A short vein that collects about two thirds of the venous blood from the MYOCARDIUM and drains into the RIGHT ATRIUM. Coronary sinus, normally located between the LEFT ATRIUM and LEFT VENTRICLE on the posterior surface of the heart, can serve as an anatomical reference for cardiac procedures.
The veins and arteries of the HEART.
Radiography of the vascular system of the heart muscle after injection of a contrast medium.
The circulation of blood through the CORONARY VESSELS of the HEART.
Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.
The dilatation of the aortic wall behind each of the cusps of the aortic valve.
Dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.
Narrowing or constriction of a coronary artery.
Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.
Large endothelium-lined venous channels situated between the two layers of DURA MATER, the endosteal and the meningeal layers. They are devoid of valves and are parts of the venous system of dura mater. Major cranial sinuses include a postero-superior group (such as superior sagittal, inferior sagittal, straight, transverse, and occipital) and an antero-inferior group (such as cavernous, petrosal, and basilar plexus).
The air space located in the body of the MAXILLARY BONE near each cheek. Each maxillary sinus communicates with the middle passage (meatus) of the NASAL CAVITY on the same side.
An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.
Air-filled spaces located within the bones around the NASAL CAVITY. They are extensions of the nasal cavity and lined by the ciliated NASAL MUCOSA. Each sinus is named for the cranial bone in which it is located, such as the ETHMOID SINUS; the FRONTAL SINUS; the MAXILLARY SINUS; and the SPHENOID SINUS.
Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.
An irregularly shaped venous space in the dura mater at either side of the sphenoid bone.
Malformations of CORONARY VESSELS, either arteries or veins. Included are anomalous origins of coronary arteries; ARTERIOVENOUS FISTULA; CORONARY ANEURYSM; MYOCARDIAL BRIDGING; and others.
Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.
Abnormal balloon- or sac-like dilatation in the wall of CORONARY VESSELS. Most coronary aneurysms are due to CORONARY ATHEROSCLEROSIS, and the rest are due to inflammatory diseases, such as KAWASAKI DISEASE.
The venous trunk which returns blood from the head, neck, upper extremities and chest.
The dilated portion of the common carotid artery at its bifurcation into external and internal carotids. It contains baroreceptors which, when stimulated, cause slowing of the heart, vasodilatation, and a fall in blood pressure.
Spasm of the large- or medium-sized coronary arteries.
The chambers of the heart, to which the BLOOD returns from the circulation.
Removal of tissue with electrical current delivered via electrodes positioned at the distal end of a catheter. Energy sources are commonly direct current (DC-shock) or alternating current at radiofrequencies (usually 750 kHz). The technique is used most often to ablate the AV junction and/or accessory pathways in order to interrupt AV conduction and produce AV block in the treatment of various tachyarrhythmias.
One of the paired, but seldom symmetrical, air spaces located between the inner and outer compact layers of the FRONTAL BONE in the forehead.
Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.
Diseases affecting or involving the PARANASAL SINUSES and generally manifesting as inflammation, abscesses, cysts, or tumors.
One of the paired air spaces located in the body of the SPHENOID BONE behind the ETHMOID BONE in the middle of the skull. Sphenoid sinus communicates with the posterosuperior part of NASAL CAVITY on the same side.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A device designed to stimulate, by electric impulses, contraction of the heart muscles. It may be temporary (external) or permanent (internal or internal-external).
An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.
NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Abnormal cardiac rhythm that is characterized by rapid, uncoordinated firing of electrical impulses in the upper chambers of the heart (HEART ATRIA). In such case, blood cannot be effectively pumped into the lower chambers of the heart (HEART VENTRICLES). It is caused by abnormal impulse generation.
Coagulation of blood in any of the CORONARY VESSELS. The presence of a blood clot (THROMBUS) often leads to MYOCARDIAL INFARCTION.
A small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus. It gives rise to the atrioventricular bundle of the conduction system of the heart.
Methods to induce and measure electrical activities at specific sites in the heart to diagnose and treat problems with the heart's electrical system.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
Formation or presence of a blood clot (THROMBUS) in the CRANIAL SINUSES, large endothelium-lined venous channels situated within the SKULL. Intracranial sinuses, also called cranial venous sinuses, include the superior sagittal, cavernous, lateral, petrous sinuses, and many others. Cranial sinus thrombosis can lead to severe HEADACHE; SEIZURE; and other neurological defects.
A procedure to stop the contraction of MYOCARDIUM during HEART SURGERY. It is usually achieved with the use of chemicals (CARDIOPLEGIC SOLUTIONS) or cold temperature (such as chilled perfusate).
A condition caused by dysfunctions related to the SINOATRIAL NODE including impulse generation (CARDIAC SINUS ARREST) and impulse conduction (SINOATRIAL EXIT BLOCK). It is characterized by persistent BRADYCARDIA, chronic ATRIAL FIBRILLATION, and failure to resume sinus rhythm following CARDIOVERSION. This syndrome can be congenital or acquired, particularly after surgical correction for heart defects.
Rapid, irregular atrial contractions caused by a block of electrical impulse conduction in the right atrium and a reentrant wave front traveling up the inter-atrial septum and down the right atrial free wall or vice versa. Unlike ATRIAL FIBRILLATION which is caused by abnormal impulse generation, typical atrial flutter is caused by abnormal impulse conduction. As in atrial fibrillation, patients with atrial flutter cannot effectively pump blood into the lower chambers of the heart (HEART VENTRICLES).
The hollow, muscular organ that maintains the circulation of the blood.
The numerous (6-12) small thin-walled spaces or air cells in the ETHMOID BONE located between the eyes. These air cells form an ethmoidal labyrinth.
Abnormally rapid heartbeats caused by reentry circuit in or around the SINOATRIAL NODE. It is characterized by sudden onset and offset episodes of tachycardia with a HEART RATE of 100-150 beats per minute. The P wave is identical to the sinus P wave but with a longer PR interval.
Recurrent narrowing or constriction of a coronary artery following surgical procedures performed to alleviate a prior obstruction.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).
Small band of specialized CARDIAC MUSCLE fibers that originates in the ATRIOVENTRICULAR NODE and extends into the membranous part of the interventricular septum. The bundle of His, consisting of the left and the right bundle branches, conducts the electrical impulses to the HEART VENTRICLES in generation of MYOCARDIAL CONTRACTION.
Elements of limited time intervals, contributing to particular results or situations.
Complete blockage of blood flow through one of the CORONARY ARTERIES, usually from CORONARY ATHEROSCLEROSIS.
Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.
Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.
The hemodynamic and electrophysiological action of the HEART ATRIA.
Types of artificial pacemakers with implantable leads to be placed at multiple intracardial sites. They are used to treat various cardiac conduction disturbances which interfere with the timing of contraction of the ventricles. They may or may not include defibrillating electrodes (IMPLANTABLE DEFIBRILLATORS) as well.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
A family of percutaneous techniques that are used to manage CORONARY OCCLUSION, including standard balloon angioplasty (PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY), the placement of intracoronary STENTS, and atheroablative technologies (e.g., ATHERECTOMY; ENDARTERECTOMY; THROMBECTOMY; PERCUTANEOUS TRANSLUMINAL LASER ANGIOPLASTY). PTCA was the dominant form of PCI, before the widespread use of stenting.
Catheters inserted into various locations within the heart for diagnostic or therapeutic purposes.
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
Tumors or cancer of the PARANASAL SINUSES.
An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.
Radiographic visualization or recording of a vein after the injection of contrast medium.
Abnormally rapid heartbeats caused by reentry of atrial impulse into the dual (fast and slow) pathways of ATRIOVENTRICULAR NODE. The common type involves a blocked atrial impulse in the slow pathway which reenters the fast pathway in a retrograde direction and simultaneously conducts to the atria and the ventricles leading to rapid HEART RATE of 150-250 beats per minute.
The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.
A generic expression for any tachycardia that originates above the BUNDLE OF HIS.
Surgical insertion of a prosthesis.
The thin membrane-like muscular structure separating the right and the left upper chambers (HEART ATRIA) of a heart.
The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).
Simple rapid heartbeats caused by rapid discharge of impulses from the SINOATRIAL NODE, usually between 100 and 180 beats/min in adults. It is characterized by a gradual onset and termination. Sinus tachycardia is common in infants, young children, and adults during strenuous physical activities.
Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.
The hospital unit in which patients with acute cardiac disorders receive intensive care.
The condition of an anatomical structure's being dilated beyond normal dimensions.
The vessels carrying blood away from the capillary beds.
Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.
A form of ventricular pre-excitation characterized by a short PR interval and a long QRS interval with a delta wave. In this syndrome, atrial impulses are abnormally conducted to the HEART VENTRICLES via an ACCESSORY CONDUCTING PATHWAY that is located between the wall of the right or left atria and the ventricles, also known as a BUNDLE OF KENT. The inherited form can be caused by mutation of PRKAG2 gene encoding a gamma-2 regulatory subunit of AMP-activated protein kinase.
A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.
Recording of regional electrophysiological information by analysis of surface potentials to give a complete picture of the effects of the currents from the heart on the body surface. It has been applied to the diagnosis of old inferior myocardial infarction, localization of the bypass pathway in Wolff-Parkinson-White syndrome, recognition of ventricular hypertrophy, estimation of the size of a myocardial infarct, and the effects of different interventions designed to reduce infarct size. The limiting factor at present is the complexity of the recording and analysis, which requires 100 or more electrodes, sophisticated instrumentation, and dedicated personnel. (Braunwald, Heart Disease, 4th ed)
In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
Production of an image when x-rays strike a fluorescent screen.
Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.
Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.
A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.
Abnormally rapid heartbeats with sudden onset and cessation.
Tumors or cancer of the MAXILLARY SINUS. They represent the majority of paranasal neoplasms.
Drugs used to cause dilation of the blood vessels.
PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
This structure includes the thin muscular atrial septum between the two HEART ATRIA, and the thick muscular ventricular septum between the two HEART VENTRICLES.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.
An abnormal direct communication between an artery and a vein without passing through the CAPILLARIES. An A-V fistula usually leads to the formation of a dilated sac-like connection, arteriovenous aneurysm. The locations and size of the shunts determine the degree of effects on the cardiovascular functions such as BLOOD PRESSURE and HEART RATE.
The valve between the left atrium and left ventricle of the heart.
The veins that return the oxygenated blood from the lungs to the left atrium of the heart.
A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.
Abnormally rapid heartbeats originating from one or more automatic foci (nonsinus pacemakers) in the HEART ATRIUM but away from the SINOATRIAL NODE. Unlike the reentry mechanism, automatic tachycardia speeds up and slows down gradually. The episode is characterized by a HEART RATE between 135 to less than 200 beats per minute and lasting 30 seconds or longer.
Impaired conduction of cardiac impulse that can occur anywhere along the conduction pathway, such as between the SINOATRIAL NODE and the right atrium (SA block) or between atria and ventricles (AV block). Heart blocks can be classified by the duration, frequency, or completeness of conduction block. Reversibility depends on the degree of structural or functional defects.
An electrical current applied to the HEART to terminate a disturbance of its rhythm, ARRHYTHMIAS, CARDIAC. (Stedman, 25th ed)
ANGINA PECTORIS or angina-like chest pain with a normal coronary arteriogram and positive EXERCISE TEST. The cause of the syndrome is unknown. While its recognition is of clinical importance, its prognosis is excellent. (Braunwald, Heart Disease, 4th ed, p1346; Jablonski Dictionary of Syndromes & Eponymic Diseases, 2d ed). It is different from METABOLIC SYNDROME X, a syndrome characterized by INSULIN RESISTANCE and HYPERINSULINEMIA, that has increased risk for cardiovascular disease.
Surgery performed on the heart.
A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)
A hair-containing cyst or sinus, occurring chiefly in the coccygeal region.
Methods of creating machines and devices.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body.
The restoration of the sequential order of contraction and relaxation of the HEART ATRIA and HEART VENTRICLES by atrio-biventricular pacing.
The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.
The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.
Abnormally rapid heartbeat, usually with a HEART RATE above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia.
The use of ultrasound to guide minimally invasive surgical procedures such as needle ASPIRATION BIOPSY; DRAINAGE; etc. Its widest application is intravascular ultrasound imaging but it is useful also in urology and intra-abdominal conditions.
Diversion of blood flow through a circuit located outside the body but continuous with the bodily circulation.
Maintenance of blood flow to an organ despite obstruction of a principal vessel. Blood flow is maintained through small vessels.
Persistent and reproducible chest discomfort usually precipitated by a physical exertion that dissipates upon cessation of such an activity. The symptoms are manifestations of MYOCARDIAL ISCHEMIA.
The return of a sign, symptom, or disease after a remission.
A type of heart valve surgery that involves the repair, replacement, or reconstruction of the annulus of the MITRAL VALVE. It includes shortening the circumference of the annulus to improve valve closing capacity and reinforcing the annulus as a step in more complex valve repairs.
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
The two large endothelium-lined venous channels that begin at the internal occipital protuberance at the back and lower part of the CRANIUM and travels laterally and forward ending in the internal jugular vein (JUGULAR VEINS). One of the transverse sinuses, usually the right one, is the continuation of the SUPERIOR SAGITTAL SINUS. The other transverse sinus is the continuation of the straight sinus.
Pathologic deposition of calcium salts in tissues.
The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
A condition in which the LEFT VENTRICLE of the heart was functionally impaired. This condition usually leads to HEART FAILURE; MYOCARDIAL INFARCTION; and other cardiovascular complications. Diagnosis is made by measuring the diminished ejection fraction and a depressed level of motility of the left ventricular wall.
Coronary artery bypass surgery on a beating HEART without a CARDIOPULMONARY BYPASS (diverting the flow of blood from the heart and lungs through an oxygenator).
An abnormal passage between two or more BLOOD VESSELS, between ARTERIES; VEINS; or between an artery and a vein.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.
The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)
Precordial pain at rest, which may precede a MYOCARDIAL INFARCTION.
The restoration of blood supply to the myocardium. (From Dorland, 28th ed)
The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
The long large endothelium-lined venous channel on the top outer surface of the brain. It receives blood from a vein in the nasal cavity, runs backwards, and gradually increases in size as blood drains from veins of the brain and the DURA MATER. Near the lower back of the CRANIUM, the superior sagittal sinus deviates to one side (usually the right) and continues on as one of the TRANSVERSE SINUSES.
An abnormal balloon- or sac-like dilatation in the wall of AORTA.
Solutions which, upon administration, will temporarily arrest cardiac activity. They are used in the performance of heart surgery.
Contractile activity of the MYOCARDIUM.
Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.
Treatment process involving the injection of fluid into an organ or tissue.
The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.
A volatile vasodilator which relieves ANGINA PECTORIS by stimulating GUANYLATE CYCLASE and lowering cytosolic calcium. It is also sometimes used for TOCOLYSIS and explosives.
The innermost layer of the heart, comprised of endothelial cells.
Types of spiral computed tomography technology in which multiple slices of data are acquired simultaneously improving the resolution over single slice acquisition technology.
The vein accompanying the femoral artery in the same sheath; it is a continuation of the popliteal vein and becomes the external iliac vein.
The symptom of paroxysmal pain consequent to MYOCARDIAL ISCHEMIA usually of distinctive character, location and radiation. It is thought to be provoked by a transient stressful situation during which the oxygen requirements of the MYOCARDIUM exceed that supplied by the CORONARY CIRCULATION.
Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.
Abnormalities in any part of the HEART SEPTUM resulting in abnormal communication between the left and the right chambers of the heart. The abnormal blood flow inside the heart may be caused by defects in the ATRIAL SEPTUM, the VENTRICULAR SEPTUM, or both.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.
Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.
Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.
A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.
The creation and display of functional images showing where the blood is flowing into the MYOCARDIUM by following over time the distribution of tracers injected into the blood stream.
A spectrum of congenital, inherited, or acquired abnormalities in BLOOD VESSELS that can adversely affect the normal blood flow in ARTERIES or VEINS. Most are congenital defects such as abnormal communications between blood vessels (fistula), shunting of arterial blood directly into veins bypassing the CAPILLARIES (arteriovenous malformations), formation of large dilated blood blood-filled vessels (cavernous angioma), and swollen capillaries (capillary telangiectases). In rare cases, vascular malformations can result from trauma or diseases.
Developmental abnormalities in any portion of the ATRIAL SEPTUM resulting in abnormal communications between the two upper chambers of the heart. Classification of atrial septal defects is based on location of the communication and types of incomplete fusion of atrial septa with the ENDOCARDIAL CUSHIONS in the fetal heart. They include ostium primum, ostium secundum, sinus venosus, and coronary sinus defects.
Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.
Backflow of blood from the LEFT VENTRICLE into the LEFT ATRIUM due to imperfect closure of the MITRAL VALVE. This can lead to mitral valve regurgitation.
Measurement of intracardiac blood flow using an M-mode and/or two-dimensional (2-D) echocardiogram while simultaneously recording the spectrum of the audible Doppler signal (e.g., velocity, direction, amplitude, intensity, timing) reflected from the moving column of red blood cells.
A paravertebral sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglia.
A form of CARDIAC MUSCLE disease that is characterized by ventricular dilation, VENTRICULAR DYSFUNCTION, and HEART FAILURE. Risk factors include SMOKING; ALCOHOL DRINKING; HYPERTENSION; INFECTION; PREGNANCY; and mutations in the LMNA gene encoding LAMIN TYPE A, a NUCLEAR LAMINA protein.
A pouch or sac developed from a tubular or saccular organ, such as the GASTROINTESTINAL TRACT.
Abnormal communication between two ARTERIES that may result from injury or occur as a congenital abnormality.
Substances used to allow enhanced visualization of tissues.
Pressure, burning, or numbness in the chest.
Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.
Surgery performed on the heart or blood vessels.
Removal of an implanted therapeutic or prosthetic device.
The flow of BLOOD through or around an organ or region of the body.
Damage to the MYOCARDIUM resulting from MYOCARDIAL REPERFUSION (restoration of blood flow to ischemic areas of the HEART.) Reperfusion takes place when there is spontaneous thrombolysis, THROMBOLYTIC THERAPY, collateral flow from other coronary vascular beds, or reversal of vasospasm.
Pathological conditions involving the HEART including its structural and functional abnormalities.
A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.
Impaired impulse conduction from HEART ATRIA to HEART VENTRICLES. AV block can mean delayed or completely blocked impulse conduction.
Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.
A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.
A congenital defect in which the heart is located on the right side of the THORAX instead of on the left side (levocardia, the normal position). When dextrocardia is accompanied with inverted HEART ATRIA, a right-sided STOMACH, and a left-sided LIVER, the combination is called dextrocardia with SITUS INVERSUS. Dextrocardia may adversely affect other thoracic organs.
Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.
Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.
Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
The study of the electrical activity and characteristics of the HEART; MYOCARDIUM; and CARDIOMYOCYTES.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. It is generated within the ventricle below the BUNDLE OF HIS, either as autonomic impulse formation or reentrant impulse conduction. Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation).
Use of a balloon CATHETER to block the flow of blood through an artery or vein.
A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)
The hemodynamic and electrophysiological action of the RIGHT ATRIUM.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
The omission of atrial activation that is caused by transient cessation of impulse generation at the SINOATRIAL NODE. It is characterized by a prolonged pause without P wave in an ELECTROCARDIOGRAM. Sinus arrest has been associated with sleep apnea (REM SLEEP-RELATED SINUS ARREST).
Drugs that bind to but do not activate beta-adrenergic receptors thereby blocking the actions of beta-adrenergic agonists. Adrenergic beta-antagonists are used for treatment of hypertension, cardiac arrhythmias, angina pectoris, glaucoma, migraine headaches, and anxiety.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
Failure of equipment to perform to standard. The failure may be due to defects or improper use.
Ear-shaped appendage of either atrium of the heart. (Dorland, 28th ed)
Veins draining the cerebrum.
The period following a surgical operation.
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
Generally, restoration of blood supply to heart tissue which is ischemic due to decrease in normal blood supply. The decrease may result from any source including atherosclerotic obstruction, narrowing of the artery, or surgical clamping. Reperfusion can be induced to treat ischemia. Methods include chemical dissolution of an occluding thrombus, administration of vasodilator drugs, angioplasty, catheterization, and artery bypass graft surgery. However, it is thought that reperfusion can itself further damage the ischemic tissue, causing MYOCARDIAL REPERFUSION INJURY.
The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.
Surgical insertion of synthetic material to repair injured or diseased heart valves.
Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)
The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.
Implantable devices which continuously monitor the electrical activity of the heart and automatically detect and terminate ventricular tachycardia (TACHYCARDIA, VENTRICULAR) and VENTRICULAR FIBRILLATION. They consist of an impulse generator, batteries, and electrodes.
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
A group of diseases in which the dominant feature is the involvement of the CARDIAC MUSCLE itself. Cardiomyopathies are classified according to their predominant pathophysiological features (DILATED CARDIOMYOPATHY; HYPERTROPHIC CARDIOMYOPATHY; RESTRICTIVE CARDIOMYOPATHY) or their etiological/pathological factors (CARDIOMYOPATHY, ALCOHOLIC; ENDOCARDIAL FIBROELASTOSIS).
Agents that affect the rate or intensity of cardiac contraction, blood vessel diameter, or blood volume.
A nonselective alpha-adrenergic antagonist. It is used in the treatment of hypertension and hypertensive emergencies, pheochromocytoma, vasospasm of RAYNAUD DISEASE and frostbite, clonidine withdrawal syndrome, impotence, and peripheral vascular disease.
A condition characterized by the growth of unencapsulated masses of ADIPOSE TISSUE symmetrically deposited around the neck, shoulders, or other sites around the body.

Coronary artery fistula from the left circumflex to the coronary sinus. (1/174)

A 27-year-old woman, who had received mitral valve repair for mitral regurgitation resulting from infective endocarditis, was admitted for a close examination of abnormal echocardiographic findings in the left atrium. Transthoracic echocardiography showed trivial mitral regurgitation with normal left ventricular contraction and dilatation of the coronary sinus. Auscultation revealed a grade 2 continuous murmur along the left sternal border. Transesophageal echocardiography demonstrated a marked dilatation of the coronary sinus just behind the posterior wall of the left atrium and turbulent blood flow in the dilated coronary sinus. Cardiac catheterization showed no significant step-up of oxygen saturation in the right heart and normal pulmonary artery pressure. Coronary angiography revealed a markedly dilated and tortuous circumflex coronary artery connected to the coronary sinus through a fistula. A left circumflex artery with a fistulous connection to the coronary sinus is extremely rare.  (+info)

Thoracic vein arrhythmias. (2/174)

The thoracic veins are important foci for the genesis of ectopic atrial tachycardia and play a critical role in the pathophysiology of paroxysmal and permanent atrial fibrillation. The pulmonary veins have the highest arrhythmogenic activity and other venous structures (eg, superior vena cava, coronary sinus and ligament of Marshall) have also been shown arrhythmogenic potential. Thoracic veins contain cardiomyocytes with distinct electrical activities and complex anatomical structures. This review summaries the current understanding of the basic and clinical electrophysiology of thoracic vein arrhythmias.  (+info)

Catheter ablation therapy for atrial fibrillation: current advancements in strategies. (3/174)

Curing atrial fibrillation (AF) by catheter ablation has significantly improved patient morbidity and mortality. The circumferential pulmonary vein isolation technique is established as the principal procedure, with a high cure rate and acceptable safety, for paroxysmal AF, but new adjunctive ablation strategies targeting the AF substrates and sources for long-standing persistent/chronic AF have been developed. These new techniques include linear ablation, complex fractionated atrial electrogram guided ablation, dominant frequency map-guided ablation, ganglionated plexi ablation and disconnection of the coronary sinus and superior vena cava to ablate the AF substrates and sources. The long-term usefulness of the established technique and these innovative adjunctive approaches for the treatment of AF remains to be investigated.  (+info)

A novel technique for placement of coronary sinus pacing leads in cardiac resynchronization therapy. (4/174)

A new technique for the placement of left ventricular pacing leads in the tributaries of the coronary sinus (CS) is described. Antegrade visualization of the CS is accomplished by selective coronary angiography, and a hydrophilic 0.032 in. wire is advanced along the CS. This facilitates the advancement of a CS sheath over a multipurpose diagnostic catheter. A hydrophilic angioplasty wire is then utilized for the negotiation of the inferior left ventricular vein and successful placement of the left ventricular pacing lead.  (+info)

Stabilization of the coronary sinus lead position with permanent stylet to prevent and treat dislocation. (5/174)

AIMS: Coronary sinus (CS) leads used for cardiac resynchronization have undergone development in the last years. However, dislocation rate remained high. We explain a simple method to stabilize the CS lead position. METHODS AND RESULTS: Thirty-five patients (11 females, aged 60 +/- 9.2 years) were treated with this method. An over-the-wire left ventricular (LV) pacing lead system was introduced and lodged in the vessel. Then, a stiff stylet was inserted and kept into the CS lead and end of the stylet was cut by a scissor (permanent stylet technique). Pacing and sensing properties of all leads were checked and the guiding sheath was removed. Control echocardiography did not show pericardial effusion. The mean LVpacing threshold was 1.2 +/- 0.8 V and the mean impedance was 625 +/- 143 Omega at the implantation. During follow-up (12.5 +/- 2.5 months), there were no statistically significant changes in pacing threshold and impedance when compared with the implantation measurements. At the last patient visit, the mean LV pacing threshold was 1.1 +/- 0.8 V and the mean impedance was 620 +/- 140 Omega. Impedance measurements did not suggest lead insulation failure. No LV lead dislocations were detected in our 35 cases during the follow-up. CONCLUSION: Permanent stylet technique seems to be a safe and effective procedure to stabilize CS lead position as demonstrated by our 1-year long follow-up results.  (+info)

A novel method of multisite atrial pacing, incorporating Bachmann's bundle area and coronary sinus ostium, for electrical atrial resynchronization in patients with recurrent atrial fibrillation. (6/174)

AIMS: The aim of the study was to assess efficacy and safety of a novel method of multisite atrial pacing, incorporating Bachmann's bundle (BB) and coronary sinus (CS) ostium pacing, which was implemented for the first time in atrial fibrillation (AF) patients with intra-atrial conduction delay. METHODS AND RESULTS: This follow-up study included 97 patients with drug refractory symptomatic AF, sinus node dysfunction, sinus P-wave > or = 120 ms, and normal atrioventricular conduction. Pacing efficacy was assessed on the basis of two main endpoints: successful rhythm control and the absence of documented or symptomatic AF. During the mean 2.3 +/- 0.7 years of follow-up, the survival rate was 99%, pacing maintenance rate 97%, and the need for re-operation 5%. Rhythm control efficacy was 90%, and 14 patients had no evidence of recurrent AF. After implantation, the mean number of anti-arrhythmic drugs used (P < 0.0001), the need for cardioversion (P < 0.01), and the incidence (P < 0.0001) and duration (P < 0.001) of AF-related hospitalizations decreased. P-wave duration with multisite atrial pacing was shorter than during sinus rhythm, BB, and CS pacing (P < 0.0001). CONCLUSION: A novel method of multisite atrial pacing is safe, provides effective long-term rhythm control, and decreases the necessity for adjunctive therapies in patients with refractory AF and intra-atrial conduction delay.  (+info)

Anatomic relations of the Marshall vein: importance for catheterization of the coronary sinus in ablation procedures. (7/174)

AIMS: Our objective was to study the anatomic relations of the human left atrial oblique vein (Marshall vein), particularly of its ostium opening into the coronary sinus, in order to guide ablation procedures related to that vein. METHODS AND RESULTS: The study was carried out in 23 heart-specimens (mean weight 446 +/- 204 g) of individuals whose mean ages were 43 +/- 21 years, 20 males. The coronary sinus was opened longitudinally, exposing the ostium of the tributary veins; the Vieussens valve was looked for, as well as its relationship to the left atrial oblique vein. The diameters of the left atrial oblique vein and the coronary sinus ostia were measured and the distance between them was determined. The left atrial oblique vein could be identified in 20 (87%) of the hearts, while the Vieussens valve was present in 17 (74%) of the specimens (in 16 of which the left atrial oblique vein was identified). In such condition, the vein was adjacent to the Vieussens valve and proximally positioned relative to the coronary sinus ostium in most of them (14/16 cases). The mean diameters of the left atrial oblique vein and of the coronary sinus ostia were, respectively, 1.23 +/- 0.38 and 8.22 +/- 1.88 mm. The mean distance between both ostia was 30.9 +/- 10.2 mm. CONCLUSION: When present, the left atrial oblique vein can be easily recognized, adjacent to the Vieussens valve. The mean distance between the coronary sinus opening and left atrial oblique vein ostium was around 30 mm, independently of the heart weight and the presence of cardiomegaly.  (+info)

Functional bundle branch block and orthodromic reciprocating tachycardia cycle length: do not bet on accessory pathway location. (8/174)

AIMS: To show 2 examples in which the analysis of the effect of bundle branch block on orthodromic reciprocating tachycardia cycle length was misleading. METHODS AND RESULTS: We performed an electrophysiological study in two patients with orthodromic reciprocating tachycardia showing a transition from wide to narrow QRS during tachycardia. Our two cases of left bundle branch block during reciprocating tachycardia using infero-septal pathways show that ventricular to atrial conduction time prolongation may be larger than 30 ms and may be concealed by a shortening of atrial to ventricular conduction time. In the 2 cases, the atrial insertion of the accessory pathway could be successfully ablated from the right atria at the ostium of the coronary sinus. CONCLUSIONS: The observation of the association between left bundle branch block and cycle length prolongation during reciprocating tachycardia may be associated with a successful ablation at the ostium of the coronary sinus.  (+info)

The coronary sinus is a large vein that receives blood from the heart's muscle tissue. It is located on the posterior side of the heart and is a part of the cardiovascular system. The coronary sinus collects oxygen-depleted blood from the myocardium (the heart muscle) and drains it into the right atrium, where it will then be pumped to the lungs for oxygenation.

The coronary sinus is an essential structure in medical procedures such as cardiac catheterization and electrophysiological studies. It is also a common site for the implantation of pacemakers and other cardiac devices.

Coronary vessels refer to the network of blood vessels that supply oxygenated blood and nutrients to the heart muscle, also known as the myocardium. The two main coronary arteries are the left main coronary artery and the right coronary artery.

The left main coronary artery branches off into the left anterior descending artery (LAD) and the left circumflex artery (LCx). The LAD supplies blood to the front of the heart, while the LCx supplies blood to the side and back of the heart.

The right coronary artery supplies blood to the right lower part of the heart, including the right atrium and ventricle, as well as the back of the heart.

Coronary vessel disease (CVD) occurs when these vessels become narrowed or blocked due to the buildup of plaque, leading to reduced blood flow to the heart muscle. This can result in chest pain, shortness of breath, or a heart attack.

Coronary angiography is a medical procedure that uses X-ray imaging to visualize the coronary arteries, which supply blood to the heart muscle. During the procedure, a thin, flexible catheter is inserted into an artery in the arm or groin and threaded through the blood vessels to the heart. A contrast dye is then injected through the catheter, and X-ray images are taken as the dye flows through the coronary arteries. These images can help doctors diagnose and treat various heart conditions, such as blockages or narrowing of the arteries, that can lead to chest pain or heart attacks. It is also known as coronary arteriography or cardiac catheterization.

Coronary circulation refers to the circulation of blood in the coronary vessels, which supply oxygenated blood to the heart muscle (myocardium) and drain deoxygenated blood from it. The coronary circulation system includes two main coronary arteries - the left main coronary artery and the right coronary artery - that branch off from the aorta just above the aortic valve. These arteries further divide into smaller branches, which supply blood to different regions of the heart muscle.

The left main coronary artery divides into two branches: the left anterior descending (LAD) artery and the left circumflex (LCx) artery. The LAD supplies blood to the front and sides of the heart, while the LCx supplies blood to the back and sides of the heart. The right coronary artery supplies blood to the lower part of the heart, including the right ventricle and the bottom portion of the left ventricle.

The veins that drain the heart muscle include the great cardiac vein, the middle cardiac vein, and the small cardiac vein, which merge to form the coronary sinus. The coronary sinus empties into the right atrium, allowing deoxygenated blood to enter the right side of the heart and be pumped to the lungs for oxygenation.

Coronary circulation is essential for maintaining the health and function of the heart muscle, as it provides the necessary oxygen and nutrients required for proper contraction and relaxation of the myocardium. Any disruption or blockage in the coronary circulation system can lead to serious consequences, such as angina, heart attack, or even death.

Coronary artery disease (CAD) is a medical condition in which the coronary arteries, which supply oxygen-rich blood to the heart muscle, become narrowed or blocked due to the buildup of cholesterol, fatty deposits, and other substances, known as plaque. Over time, this buildup can cause the arteries to harden and narrow (a process called atherosclerosis), reducing blood flow to the heart muscle.

The reduction in blood flow can lead to various symptoms and complications, including:

1. Angina (chest pain or discomfort) - This occurs when the heart muscle doesn't receive enough oxygen-rich blood, causing pain, pressure, or discomfort in the chest, arms, neck, jaw, or back.
2. Shortness of breath - When the heart isn't receiving adequate blood flow, it can't pump blood efficiently to meet the body's demands, leading to shortness of breath during physical activities or at rest.
3. Heart attack - If a piece of plaque ruptures or breaks off in a coronary artery, a blood clot can form and block the artery, causing a heart attack (myocardial infarction). This can damage or destroy part of the heart muscle.
4. Heart failure - Chronic reduced blood flow to the heart muscle can weaken it over time, leading to heart failure, a condition in which the heart can't pump blood efficiently to meet the body's needs.
5. Arrhythmias - Reduced blood flow and damage to the heart muscle can lead to abnormal heart rhythms (arrhythmias), which can be life-threatening if not treated promptly.

Coronary artery disease is typically diagnosed through a combination of medical history, physical examination, and diagnostic tests such as electrocardiograms (ECGs), stress testing, cardiac catheterization, and imaging studies like coronary computed tomography angiography (CCTA). Treatment options for CAD include lifestyle modifications, medications, medical procedures, and surgery.

The Sinus of Valsalva are three pouch-like dilations or outpouchings located at the upper part (root) of the aorta, just above the aortic valve. They are named after Antonio Maria Valsalva, an Italian anatomist and physician. These sinuses are divided into three parts:

1. Right Sinus of Valsalva: It is located to the right of the ascending aorta and usually gives rise to the right coronary artery.
2. Left Sinus of Valsalva: It is situated to the left of the ascending aorta and typically gives rise to the left coronary artery.
3. Non-coronary Sinus of Valsalva: This sinus is located in between the right and left coronary sinuses, and it does not give rise to any coronary arteries.

These sinuses play a crucial role during the cardiac cycle, particularly during ventricular contraction (systole). The pressure difference between the aorta and the ventricles causes the aortic valve cusps to be pushed into these sinuses, preventing the backflow of blood from the aorta into the ventricles.

Anatomical variations in the size and shape of the Sinuses of Valsalva can occur, and certain conditions like congenital heart diseases (e.g., aortic valve stenosis or bicuspid aortic valve) may affect their structure and function. Additionally, aneurysms or ruptures of the sinuses can lead to severe complications, such as cardiac tamponade, endocarditis, or stroke.

Coronary balloon angioplasty is a minimally invasive medical procedure used to widen narrowed or obstructed coronary arteries (the blood vessels that supply oxygen-rich blood to the heart muscle) and improve blood flow to the heart. This procedure is typically performed in conjunction with the insertion of a stent, a small mesh tube that helps keep the artery open.

During coronary balloon angioplasty, a thin, flexible catheter with a deflated balloon at its tip is inserted into a blood vessel, usually through a small incision in the groin or arm. The catheter is then guided to the narrowed or obstructed section of the coronary artery. Once in position, the balloon is inflated to compress the plaque against the artery wall and widen the lumen (the inner space) of the artery. This helps restore blood flow to the heart muscle.

The procedure is typically performed under local anesthesia and conscious sedation to minimize discomfort. Coronary balloon angioplasty is a relatively safe and effective treatment for many people with coronary artery disease, although complications such as bleeding, infection, or re-narrowing of the artery (restenosis) can occur in some cases.

Coronary stenosis is a medical condition that refers to the narrowing of the coronary arteries, which supply oxygen-rich blood to the heart muscle. This narrowing is typically caused by the buildup of plaque, made up of fat, cholesterol, and other substances, on the inner walls of the arteries. Over time, as the plaque hardens and calcifies, it can cause the artery to become narrowed or blocked, reducing blood flow to the heart muscle.

Coronary stenosis can lead to various symptoms and complications, including chest pain (angina), shortness of breath, irregular heart rhythms (arrhythmias), and heart attacks. Treatment options for coronary stenosis may include lifestyle changes, medications, medical procedures such as angioplasty or bypass surgery, or a combination of these approaches. Regular check-ups and diagnostic tests, such as stress testing or coronary angiography, can help detect and monitor coronary stenosis over time.

Coronary artery bypass surgery, also known as coronary artery bypass grafting (CABG), is a surgical procedure used to improve blood flow to the heart in patients with severe coronary artery disease. This condition occurs when the coronary arteries, which supply oxygen-rich blood to the heart muscle, become narrowed or blocked due to the buildup of fatty deposits, called plaques.

During CABG surgery, a healthy blood vessel from another part of the body is grafted, or attached, to the coronary artery, creating a new pathway for oxygen-rich blood to flow around the blocked or narrowed portion of the artery and reach the heart muscle. This bypass helps to restore normal blood flow and reduce the risk of angina (chest pain), shortness of breath, and other symptoms associated with coronary artery disease.

There are different types of CABG surgery, including traditional on-pump CABG, off-pump CABG, and minimally invasive CABG. The choice of procedure depends on various factors, such as the patient's overall health, the number and location of blocked arteries, and the presence of other medical conditions.

It is important to note that while CABG surgery can significantly improve symptoms and quality of life in patients with severe coronary artery disease, it does not cure the underlying condition. Lifestyle modifications, such as regular exercise, a healthy diet, smoking cessation, and medication therapy, are essential for long-term management and prevention of further progression of the disease.

Cranial sinuses are a part of the venous system in the human head. They are air-filled spaces located within the skull and are named according to their location. The cranial sinuses include:

1. Superior sagittal sinus: It runs along the top of the brain, inside the skull, and drains blood from the scalp and the veins of the brain.
2. Inferior sagittal sinus: It runs along the bottom of the brain and drains into the straight sinus.
3. Straight sinus: It is located at the back of the brain and receives blood from the inferior sagittal sinus and great cerebral vein.
4. Occipital sinuses: They are located at the back of the head and drain blood from the scalp and skull.
5. Cavernous sinuses: They are located on each side of the brain, near the temple, and receive blood from the eye and surrounding areas.
6. Sphenoparietal sinus: It is a small sinus that drains blood from the front part of the brain into the cavernous sinus.
7. Petrosquamosal sinuses: They are located near the ear and drain blood from the scalp and skull.

The cranial sinuses play an essential role in draining blood from the brain and protecting it from injury.

The maxillary sinuses, also known as the antrums of Highmore, are the largest of the four pairs of paranasal sinuses located in the maxilla bones. They are air-filled cavities that surround the nasolacrimal duct and are situated superior to the upper teeth and lateral to the nasal cavity. Each maxillary sinus is lined with a mucous membrane, which helps to warm, humidify, and filter the air we breathe. Inflammation or infection of the maxillary sinuses can result in conditions such as sinusitis, leading to symptoms like facial pain, headaches, and nasal congestion.

Coronary artery disease, often simply referred to as coronary disease, is a condition in which the blood vessels that supply oxygen-rich blood to the heart become narrowed or blocked due to the buildup of fatty deposits called plaques. This can lead to chest pain (angina), shortness of breath, or in severe cases, a heart attack.

The medical definition of coronary artery disease is:

A condition characterized by the accumulation of atheromatous plaques in the walls of the coronary arteries, leading to decreased blood flow and oxygen supply to the myocardium (heart muscle). This can result in symptoms such as angina pectoris, shortness of breath, or arrhythmias, and may ultimately lead to myocardial infarction (heart attack) or heart failure.

Risk factors for coronary artery disease include age, smoking, high blood pressure, high cholesterol, diabetes, obesity, physical inactivity, and a family history of the condition. Lifestyle changes such as quitting smoking, exercising regularly, eating a healthy diet, and managing stress can help reduce the risk of developing coronary artery disease. Medical treatments may include medications to control blood pressure, cholesterol levels, or irregular heart rhythms, as well as procedures such as angioplasty or bypass surgery to improve blood flow to the heart.

Paranasal sinuses are air-filled cavities in the skull that surround the nasal cavity. There are four pairs of paranasal sinuses, including the maxillary, frontal, ethmoid, and sphenoid sinuses. These sinuses help to warm, humidify, and filter the air we breathe. They also contribute to our voice resonance and provide a slight cushioning effect for the skull. The openings of the paranasal sinuses lead directly into the nasal cavity, allowing mucus produced in the sinuses to drain into the nose. Infections or inflammation of the paranasal sinuses can result in conditions such as sinusitis.

Artificial cardiac pacing is a medical procedure that involves the use of an artificial device to regulate and stimulate the contraction of the heart muscle. This is often necessary when the heart's natural pacemaker, the sinoatrial node, is not functioning properly and the heart is beating too slowly or irregularly.

The artificial pacemaker consists of a small generator that produces electrical impulses and leads that are positioned in the heart to transmit the impulses. The generator is typically implanted just under the skin in the chest, while the leads are inserted into the heart through a vein.

There are different types of artificial cardiac pacing systems, including single-chamber pacemakers, which stimulate either the right atrium or right ventricle, and dual-chamber pacemakers, which stimulate both chambers of the heart. Some pacemakers also have additional features that allow them to respond to changes in the body's needs, such as during exercise or sleep.

Artificial cardiac pacing is a safe and effective treatment for many people with abnormal heart rhythms, and it can significantly improve their quality of life and longevity.

The cavernous sinus is a venous structure located in the middle cranial fossa, which is a depression in the skull that houses several important nerves and blood vessels. The cavernous sinus is situated on either side of the sphenoid bone, near the base of the skull, and it contains several important structures:

* The internal carotid artery, which supplies oxygenated blood to the brain
* The abducens nerve (cranial nerve VI), which controls lateral movement of the eye
* The oculomotor nerve (cranial nerve III), which controls most of the muscles that move the eye
* The trochlear nerve (cranial nerve IV), which controls one of the muscles that moves the eye
* The ophthalmic and maxillary divisions of the trigeminal nerve (cranial nerve V), which transmit sensory information from the face and head

The cavernous sinus is an important structure because it serves as a conduit for several critical nerves and blood vessels. However, it is also vulnerable to various pathological conditions such as thrombosis (blood clots), infection, tumors, or aneurysms, which can lead to serious neurological deficits or even death.

Coronary vessel anomalies refer to abnormalities in the structure, origin, or course of the coronary arteries or veins. These vessels are responsible for delivering oxygenated blood to the heart muscle. Some common types of coronary vessel anomalies include:

1. Anomalous Origin of the Coronary Artery (AOCA): This occurs when one or both of the coronary arteries originate from an abnormal location in the aorta. The left coronary artery may arise from the right sinus of Valsalva, while the right coronary artery may arise from the left sinus of Valsalva. This can lead to ischemia (reduced blood flow) and potentially life-threatening complications such as sudden cardiac death.
2. Coronary Artery Fistula: A fistula is an abnormal connection between a coronary artery and another chamber or vessel in the heart. Blood flows directly from the high-pressure coronary artery into a low-pressure chamber, bypassing the capillaries and leading to a steal phenomenon where oxygenated blood is diverted away from the heart muscle.
3. Coronary Artery Aneurysm: An aneurysm is a localized dilation or bulging of the coronary artery wall. This can lead to complications such as thrombosis (blood clot formation), embolism (blockage caused by a clot that travels to another location), or rupture, which can be life-threatening.
4. Myocardial Bridge: In this condition, a segment of the coronary artery passes between the muscle fibers of the heart, instead of running along its surface. This can cause compression of the artery during systole (contraction) and lead to ischemia.
5. Kawasaki Disease: Although not strictly an anomaly, Kawasaki disease is a pediatric illness that can result in coronary artery aneurysms and other complications if left untreated.

Coronary vessel anomalies may be asymptomatic or present with symptoms such as chest pain, shortness of breath, palpitations, or syncope (fainting). Diagnosis typically involves imaging techniques such as coronary angiography, computed tomography (CT) angiography, or magnetic resonance angiography. Treatment depends on the specific anomaly and may involve medications, percutaneous interventions, or surgical correction.

Electrocardiography (ECG or EKG) is a medical procedure that records the electrical activity of the heart. It provides a graphic representation of the electrical changes that occur during each heartbeat. The resulting tracing, called an electrocardiogram, can reveal information about the heart's rate and rhythm, as well as any damage to its cells or abnormalities in its conduction system.

During an ECG, small electrodes are placed on the skin of the chest, arms, and legs. These electrodes detect the electrical signals produced by the heart and transmit them to a machine that amplifies and records them. The procedure is non-invasive, painless, and quick, usually taking only a few minutes.

ECGs are commonly used to diagnose and monitor various heart conditions, including arrhythmias, coronary artery disease, heart attacks, and electrolyte imbalances. They can also be used to evaluate the effectiveness of certain medications or treatments.

A coronary aneurysm is a localized dilation or bulging of a portion of the wall of a coronary artery, which supplies blood to the muscle tissue of the heart. It's similar to a bubble or balloon-like structure that forms within the artery wall due to weakness in the arterial wall, leading to abnormal enlargement or widening.

Coronary aneurysms can vary in size and may be classified as true or false aneurysms based on their structure. True aneurysms involve all three layers of the artery wall, while false aneurysms (also known as pseudoaneurysms) only have one or two layers involved, with the remaining layer disrupted.

These aneurysms can lead to complications such as blood clots forming inside the aneurysm sac, which can then dislodge and cause blockages in smaller coronary arteries (embolism). Additionally, coronary aneurysms may rupture, leading to severe internal bleeding and potentially life-threatening situations.

Coronary aneurysms are often asymptomatic but can present with symptoms such as chest pain, shortness of breath, or palpitations, especially if the aneurysm causes a significant narrowing (stenosis) in the affected artery. They can be diagnosed through imaging techniques like coronary angiography, computed tomography (CT), or magnetic resonance imaging (MRI). Treatment options include medications to manage symptoms and prevent complications, as well as surgical interventions such as stenting or bypass grafting to repair or reroute the affected artery.

The superior vena cava is a large vein that carries deoxygenated blood from the upper half of the body to the right atrium of the heart. It is formed by the union of the left and right brachiocephalic veins (also known as the internal jugular and subclavian veins) near the base of the neck. The superior vena cava runs posteriorly to the sternum and enters the upper right portion of the right atrium, just posterior to the opening of the inferior vena cava. It plays a crucial role in the circulatory system by allowing blood returning from the head, neck, upper limbs, and thorax to bypass the liver before entering the heart.

The carotid sinus is a small, dilated area located at the bifurcation (or fork) of the common carotid artery into the internal and external carotid arteries. It is a baroreceptor region, which means it contains specialized sensory nerve endings that can detect changes in blood pressure. When the blood pressure increases, the walls of the carotid sinus stretch, activating these nerve endings and sending signals to the brain. The brain then responds by reducing the heart rate and relaxing the blood vessels, which helps to lower the blood pressure back to normal.

The carotid sinus is an important part of the body's autonomic nervous system, which regulates various involuntary functions such as heart rate, blood pressure, and digestion. It plays a crucial role in maintaining cardiovascular homeostasis and preventing excessive increases in blood pressure that could potentially damage vital organs.

Coronary vasospasm refers to a sudden constriction (narrowing) of the coronary arteries, which supply oxygenated blood to the heart muscle. This constriction can reduce or block blood flow, leading to symptoms such as chest pain (angina) or, in severe cases, a heart attack (myocardial infarction). Coronary vasospasm can occur spontaneously or be triggered by various factors, including stress, smoking, and certain medications. It is also associated with conditions such as coronary artery disease and variant angina. Prolonged or recurrent vasospasms can cause damage to the heart muscle and increase the risk of cardiovascular events.

The heart atria are the upper chambers of the heart that receive blood from the veins and deliver it to the lower chambers, or ventricles. There are two atria in the heart: the right atrium receives oxygen-poor blood from the body and pumps it into the right ventricle, which then sends it to the lungs to be oxygenated; and the left atrium receives oxygen-rich blood from the lungs and pumps it into the left ventricle, which then sends it out to the rest of the body. The atria contract before the ventricles during each heartbeat, helping to fill the ventricles with blood and prepare them for contraction.

Catheter ablation is a medical procedure in which specific areas of heart tissue that are causing arrhythmias (irregular heartbeats) are destroyed or ablated using heat energy (radiofrequency ablation), cold energy (cryoablation), or other methods. The procedure involves threading one or more catheters through the blood vessels to the heart, where the tip of the catheter can be used to selectively destroy the problematic tissue. Catheter ablation is often used to treat atrial fibrillation, atrial flutter, and other types of arrhythmias that originate in the heart's upper chambers (atria). It may also be used to treat certain types of arrhythmias that originate in the heart's lower chambers (ventricles), such as ventricular tachycardia.

The goal of catheter ablation is to eliminate or reduce the frequency and severity of arrhythmias, thereby improving symptoms and quality of life. In some cases, it may also help to reduce the risk of stroke and other complications associated with arrhythmias. Catheter ablation is typically performed by a specialist in heart rhythm disorders (electrophysiologist) in a hospital or outpatient setting under local anesthesia and sedation. The procedure can take several hours to complete, depending on the complexity of the arrhythmia being treated.

It's important to note that while catheter ablation is generally safe and effective, it does carry some risks, such as bleeding, infection, damage to nearby structures, and the possibility of recurrent arrhythmias. Patients should discuss the potential benefits and risks of the procedure with their healthcare provider before making a decision about treatment.

A frontal sinus is a paired, air-filled paranasal sinus located in the frontal bone of the skull, above the eyes and behind the forehead. It is one of the four pairs of sinuses found in the human head. The frontal sinuses are lined with mucous membrane and are interconnected with the nasal cavity through small openings called ostia. They help to warm, humidify, and filter the air we breathe, and contribute to the resonance of our voice. Variations in size, shape, and asymmetry of frontal sinuses are common among individuals.

Cardiac catheterization is a medical procedure used to diagnose and treat cardiovascular conditions. In this procedure, a thin, flexible tube called a catheter is inserted into a blood vessel in the arm or leg and threaded up to the heart. The catheter can be used to perform various diagnostic tests, such as measuring the pressure inside the heart chambers and assessing the function of the heart valves.

Cardiac catheterization can also be used to treat certain cardiovascular conditions, such as narrowed or blocked arteries. In these cases, a balloon or stent may be inserted through the catheter to open up the blood vessel and improve blood flow. This procedure is known as angioplasty or percutaneous coronary intervention (PCI).

Cardiac catheterization is typically performed in a hospital cardiac catheterization laboratory by a team of healthcare professionals, including cardiologists, radiologists, and nurses. The procedure may be done under local anesthesia with sedation or general anesthesia, depending on the individual patient's needs and preferences.

Overall, cardiac catheterization is a valuable tool in the diagnosis and treatment of various heart conditions, and it can help improve symptoms, reduce complications, and prolong life for many patients.

Paranasal sinus diseases refer to a group of medical conditions that affect the paranasal sinuses, which are air-filled cavities located within the skull near the nasal cavity. These sinuses include the maxillary, frontal, ethmoid, and sphenoid sinuses.

Paranasal sinus diseases can be caused by a variety of factors, including viral, bacterial, or fungal infections, allergies, structural abnormalities, or autoimmune disorders. Some common paranasal sinus diseases include:

1. Sinusitis: Inflammation or infection of the sinuses, which can cause symptoms such as nasal congestion, thick nasal discharge, facial pain or pressure, and reduced sense of smell.
2. Nasal polyps: Soft, benign growths that develop in the lining of the nasal passages or sinuses, which can obstruct airflow and cause difficulty breathing through the nose.
3. Sinonasal tumors: Abnormal growths that can be benign or malignant, which can cause symptoms such as nasal congestion, facial pain, and bleeding from the nose.
4. Sinus cysts: Fluid-filled sacs that form in the sinuses, which can cause symptoms similar to those of sinusitis.
5. Fungal sinusitis: Infection of the sinuses with fungi, which can cause symptoms such as nasal congestion, facial pain, and thick, discolored mucus.

Treatment for paranasal sinus diseases depends on the underlying cause and severity of the condition. Treatment options may include medications, such as antibiotics, antihistamines, or corticosteroids, as well as surgical intervention in more severe cases.

The sphenoid sinuses are air-filled spaces located within the sphenoid bone, which is one of the bones that make up the skull base. These sinuses are located deep inside the skull, behind the eyes and nasal cavity. They are paired and separated by a thin bony septum, and each one opens into the corresponding nasal cavity through a small opening called the sphenoethmoidal recess. The sphenoid sinuses vary greatly in size and shape between individuals. They develop during childhood and continue to grow until early adulthood. The function of the sphenoid sinuses, like other paranasal sinuses, is not entirely clear, but they may contribute to reducing the weight of the skull, resonating voice during speech, and insulating the brain from trauma.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

An artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart. It is typically used when the heart's natural pacemaker, the sinoatrial node, is not functioning properly and the heart rate is too slow or irregular. The pacemaker consists of a small generator that contains a battery and electronic circuits, which are connected to one or more electrodes that are placed in the heart.

The generator sends electrical signals through the electrodes to stimulate the heart muscle and cause it to contract, thereby maintaining a regular heart rhythm. Artificial pacemakers can be programmed to deliver electrical impulses at a specific rate or in response to the body's needs. They are typically implanted in the chest during a surgical procedure and can last for many years before needing to be replaced.

Artificial pacemakers are an effective treatment for various types of bradycardia, which is a heart rhythm disorder characterized by a slow heart rate. Pacemakers can significantly improve symptoms associated with bradycardia, such as fatigue, dizziness, shortness of breath, and fainting spells.

The heart conduction system is a group of specialized cardiac muscle cells that generate and conduct electrical impulses to coordinate the contraction of the heart chambers. The main components of the heart conduction system include:

1. Sinoatrial (SA) node: Also known as the sinus node, it is located in the right atrium near the entrance of the superior vena cava and functions as the primary pacemaker of the heart. It sets the heart rate by generating electrical impulses at regular intervals.
2. Atrioventricular (AV) node: Located in the interatrial septum, near the opening of the coronary sinus, it serves as a relay station for electrical signals between the atria and ventricles. The AV node delays the transmission of impulses to allow the atria to contract before the ventricles.
3. Bundle of His: A bundle of specialized cardiac muscle fibers that conducts electrical impulses from the AV node to the ventricles. It divides into two main branches, the right and left bundle branches, which further divide into smaller Purkinje fibers.
4. Right and left bundle branches: These are extensions of the Bundle of His that transmit electrical impulses to the respective right and left ventricular myocardium. They consist of specialized conducting tissue with large diameters and minimal resistance, allowing for rapid conduction of electrical signals.
5. Purkinje fibers: Fine, branching fibers that arise from the bundle branches and spread throughout the ventricular myocardium. They are responsible for transmitting electrical impulses to the working cardiac muscle cells, triggering coordinated ventricular contraction.

In summary, the heart conduction system is a complex network of specialized muscle cells responsible for generating and conducting electrical signals that coordinate the contraction of the atria and ventricles, ensuring efficient blood flow throughout the body.

Myocardial infarction (MI), also known as a heart attack, is a medical condition characterized by the death of a segment of heart muscle (myocardium) due to the interruption of its blood supply. This interruption is most commonly caused by the blockage of a coronary artery by a blood clot formed on the top of an atherosclerotic plaque, which is a buildup of cholesterol and other substances in the inner lining of the artery.

The lack of oxygen and nutrients supply to the heart muscle tissue results in damage or death of the cardiac cells, causing the affected area to become necrotic. The extent and severity of the MI depend on the size of the affected area, the duration of the occlusion, and the presence of collateral circulation.

Symptoms of a myocardial infarction may include chest pain or discomfort, shortness of breath, nausea, lightheadedness, and sweating. Immediate medical attention is necessary to restore blood flow to the affected area and prevent further damage to the heart muscle. Treatment options for MI include medications, such as thrombolytics, antiplatelet agents, and pain relievers, as well as procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

Atrial fibrillation (A-tre-al fi-bru-la'shun) is a type of abnormal heart rhythm characterized by rapid and irregular beating of the atria, the upper chambers of the heart. In this condition, the electrical signals that coordinate heartbeats don't function properly, causing the atria to quiver instead of contracting effectively. As a result, blood may not be pumped efficiently into the ventricles, which can lead to blood clots, stroke, and other complications. Atrial fibrillation is a common type of arrhythmia and can cause symptoms such as palpitations, shortness of breath, fatigue, and dizziness. It can be caused by various factors, including heart disease, high blood pressure, age, and genetics. Treatment options include medications, electrical cardioversion, and surgical procedures to restore normal heart rhythm.

Coronary thrombosis is a medical condition that refers to the formation of a blood clot (thrombus) inside a coronary artery, which supplies oxygenated blood to the heart muscle. The development of a thrombus can partially or completely obstruct blood flow, leading to insufficient oxygen supply to the heart muscle. This can cause chest pain (angina) or a heart attack (myocardial infarction), depending on the severity and duration of the blockage.

Coronary thrombosis often results from the rupture of an atherosclerotic plaque, a buildup of cholesterol, fat, calcium, and other substances in the inner lining (endothelium) of the coronary artery. The ruptured plaque exposes the underlying tissue to the bloodstream, triggering the coagulation cascade and resulting in the formation of a thrombus.

Immediate medical attention is crucial for managing coronary thrombosis, as timely treatment can help restore blood flow, prevent further damage to the heart muscle, and reduce the risk of complications such as heart failure or life-threatening arrhythmias. Treatment options may include medications, such as antiplatelet agents, anticoagulants, and thrombolytic drugs, or interventional procedures like angioplasty and stenting to open the blocked artery. In some cases, surgical intervention, such as coronary artery bypass grafting (CABG), may be necessary.

The atrioventricular (AV) node is a critical part of the electrical conduction system of the heart. It is a small cluster of specialized cardiac muscle cells located in the lower interatrial septum, near the opening of the coronary sinus. The AV node receives electrical impulses from the sinoatrial node (the heart's natural pacemaker) via the internodal pathways and delays their transmission for a brief period before transmitting them to the bundle of His and then to the ventricles. This delay allows the atria to contract and empty their contents into the ventricles before the ventricles themselves contract, ensuring efficient pumping of blood throughout the body.

The AV node plays an essential role in maintaining a normal heart rhythm, as it can also function as a backup pacemaker if the sinoatrial node fails to generate impulses. However, certain heart conditions or medications can affect the AV node's function and lead to abnormal heart rhythms, such as atrioventricular block or atrial tachycardia.

Electrophysiologic techniques, cardiac, refer to medical procedures used to study the electrical activities and conduction systems of the heart. These techniques involve the insertion of electrode catheters into the heart through blood vessels under fluoroscopic guidance to record and stimulate electrical signals. The information obtained from these studies can help diagnose and evaluate various cardiac arrhythmias, determine the optimal treatment strategy, and assess the effectiveness of therapies such as ablation or implantable devices.

The electrophysiologic study (EPS) is a type of cardiac electrophysiologic technique that involves the measurement of electrical signals from different regions of the heart to evaluate its conduction system's function. The procedure can help identify the location of abnormal electrical pathways responsible for arrhythmias and determine the optimal treatment strategy, such as catheter ablation or medication therapy.

Cardiac electrophysiologic techniques are also used in device implantation procedures, such as pacemaker or defibrillator implantation, to ensure proper placement and function of the devices. These techniques can help program and test the devices to optimize their settings for each patient's needs.

In summary, cardiac electrophysiologic techniques are medical procedures used to study and manipulate the electrical activities of the heart, helping diagnose and treat various arrhythmias and other cardiac conditions.

The myocardium is the middle layer of the heart wall, composed of specialized cardiac muscle cells that are responsible for pumping blood throughout the body. It forms the thickest part of the heart wall and is divided into two sections: the left ventricle, which pumps oxygenated blood to the rest of the body, and the right ventricle, which pumps deoxygenated blood to the lungs.

The myocardium contains several types of cells, including cardiac muscle fibers, connective tissue, nerves, and blood vessels. The muscle fibers are arranged in a highly organized pattern that allows them to contract in a coordinated manner, generating the force necessary to pump blood through the heart and circulatory system.

Damage to the myocardium can occur due to various factors such as ischemia (reduced blood flow), infection, inflammation, or genetic disorders. This damage can lead to several cardiac conditions, including heart failure, arrhythmias, and cardiomyopathy.

Intracranial sinus thrombosis is a medical condition characterized by the formation of a blood clot (thrombus) within the intracranial venous sinuses, which are responsible for draining blood from the brain. The condition can lead to various neurological symptoms and complications, such as increased intracranial pressure, headaches, seizures, visual disturbances, and altered consciousness. Intracranial sinus thrombosis may result from various factors, including hypercoagulable states, infections, trauma, and malignancies. Immediate medical attention is necessary for proper diagnosis and treatment to prevent potential long-term neurological damage or even death.

Induced heart arrest, also known as controlled cardiac arrest or planned cardiac arrest, is a deliberate medical intervention where cardiac activity is temporarily stopped through the use of medications or electrical disruption. This procedure is typically carried out during a surgical procedure, such as open-heart surgery, where the heart needs to be stilled to allow surgeons to work on it safely.

The most common method used to induce heart arrest is by administering a medication called potassium chloride, which stops the heart's electrical activity. Alternatively, an electrical shock may be delivered to the heart to achieve the same effect. Once the procedure is complete, the heart can be restarted using various resuscitation techniques, such as defibrillation or medication administration.

It's important to note that induced heart arrest is a carefully monitored and controlled medical procedure carried out by trained healthcare professionals in a hospital setting. It should not be confused with sudden cardiac arrest, which is an unexpected and often unpredictable event that occurs outside of a medical setting.

Sick Sinus Syndrome (SSS) is a term used to describe a group of abnormal heart rhythm disturbances that originates in the sinoatrial node (the natural pacemaker of the heart). This syndrome is characterized by impaired functioning of the sinoatrial node, resulting in various abnormalities such as sinus bradycardia (abnormally slow heart rate), sinus arrest (complete cessation of sinus node activity), and/or sinoatrial exit block (failure of the electrical impulse to leave the sinus node and spread to the atria).

People with SSS may experience symptoms such as palpitations, dizziness, fatigue, shortness of breath, or syncope (fainting) due to inadequate blood supply to the brain caused by slow heart rate. The diagnosis of SSS is typically made based on the patient's symptoms and the results of an electrocardiogram (ECG), Holter monitoring, or event recorder that shows evidence of abnormal sinus node function. Treatment options for SSS may include lifestyle modifications, medications, or implantation of a pacemaker to regulate the heart rate.

Atrial flutter is a type of abnormal heart rhythm or arrhythmia that originates in the atria - the upper chambers of the heart. In atrial flutter, the atria beat too quickly, usually between 250 and 350 beats per minute, which is much faster than the normal resting rate of 60 to 100 beats per minute.

This rapid beating causes the atria to quiver or "flutter" instead of contracting effectively. As a result, blood may not be pumped efficiently into the ventricles - the lower chambers of the heart - which can lead to reduced cardiac output and symptoms such as palpitations, shortness of breath, fatigue, dizziness, or chest discomfort.

Atrial flutter is often caused by underlying heart conditions, such as coronary artery disease, hypertension, valvular heart disease, or congenital heart defects. It can also be a complication of cardiac surgery or other medical procedures. In some cases, atrial flutter may occur without any apparent underlying cause, which is known as lone atrial flutter.

Treatment for atrial flutter typically involves medications to control the heart rate and rhythm, electrical cardioversion to restore a normal heart rhythm, or catheter ablation to destroy the abnormal electrical pathways in the heart that are causing the arrhythmia. In some cases, surgical intervention may be necessary to treat atrial flutter.

In medical terms, the heart is a muscular organ located in the thoracic cavity that functions as a pump to circulate blood throughout the body. It's responsible for delivering oxygen and nutrients to the tissues and removing carbon dioxide and other wastes. The human heart is divided into four chambers: two atria on the top and two ventricles on the bottom. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs, while the left side receives oxygenated blood from the lungs and pumps it out to the rest of the body. The heart's rhythmic contractions and relaxations are regulated by a complex electrical conduction system.

The ethmoid sinuses are a pair of air-filled spaces located in the ethmoid bone, which is a part of the skull that forms the upper portion of the nasal cavity and the inner eye socket. These sinuses are divided into anterior and posterior groups and are present in adults, but not at birth. They continue to grow and develop until early adulthood.

The ethmoid sinuses are lined with mucous membrane, which helps to warm, humidify, and filter the air we breathe. They are surrounded by a network of blood vessels and nerves, making them susceptible to inflammation and infection. Inflammation of the ethmoid sinuses can lead to conditions such as sinusitis, which can cause symptoms such as nasal congestion, headache, and facial pain.

Tachycardia is a heart rate that is faster than normal. In sinoatrial nodal reentry tachycardia (SANRT), the abnormally fast heart rhythm originates in the sinoatrial node, which is the natural pacemaker of the heart. This type of tachycardia occurs due to a reentry circuit within the sinoatrial node, where an electrical impulse travels in a circular pattern and repeatedly stimulates the node to fire off abnormal rapid heartbeats. SANRT is typically characterized by a heart rate of over 100 beats per minute, palpitations, lightheadedness, or occasionally chest discomfort. It is usually a benign condition but can cause symptoms that affect quality of life. In some cases, treatment may be required to prevent recurrences and manage symptoms.

Coronary restenosis is the re-narrowing or re-occlusion of a coronary artery after a previous successful procedure to open or widen the artery, such as angioplasty or stenting. This narrowing is usually caused by the excessive growth of scar tissue or smooth muscle cells in the artery lining, which can occur spontaneously or as a response to the initial procedure. Restenosis can lead to recurrent symptoms of coronary artery disease, such as chest pain or shortness of breath, and may require additional medical intervention.

Hemodynamics is the study of how blood flows through the cardiovascular system, including the heart and the vascular network. It examines various factors that affect blood flow, such as blood volume, viscosity, vessel length and diameter, and pressure differences between different parts of the circulatory system. Hemodynamics also considers the impact of various physiological and pathological conditions on these variables, and how they in turn influence the function of vital organs and systems in the body. It is a critical area of study in fields such as cardiology, anesthesiology, and critical care medicine.

Myocardial ischemia is a condition in which the blood supply to the heart muscle (myocardium) is reduced or blocked, leading to insufficient oxygen delivery and potential damage to the heart tissue. This reduction in blood flow typically results from the buildup of fatty deposits, called plaques, in the coronary arteries that supply the heart with oxygen-rich blood. The plaques can rupture or become unstable, causing the formation of blood clots that obstruct the artery and limit blood flow.

Myocardial ischemia may manifest as chest pain (angina pectoris), shortness of breath, fatigue, or irregular heartbeats (arrhythmias). In severe cases, it can lead to myocardial infarction (heart attack) if the oxygen supply is significantly reduced or cut off completely, causing permanent damage or death of the heart muscle. Early diagnosis and treatment of myocardial ischemia are crucial for preventing further complications and improving patient outcomes.

The Bundle of His is a bundle of specialized cardiac muscle fibers that conduct electrical impulses to the Purkinje fibers, which then stimulate contraction of the ventricles in the heart. It is named after Wilhelm His, Jr., who first described it in 1893.

The Bundle of His is a part of the electrical conduction system of the heart that helps coordinate the contraction of the atria and ventricles to ensure efficient pumping of blood. The bundle originates from the atrioventricular node, which receives electrical impulses from the sinoatrial node (the heart's natural pacemaker) and transmits them through the Bundle of His to the Purkinje fibers.

The Bundle of His is divided into two main branches, known as the right and left bundle branches, which further divide into smaller fascicles that spread throughout the ventricular myocardium. This ensures a coordinated contraction of the ventricles, allowing for efficient pumping of blood to the rest of the body.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Coronary occlusion is the medical term used to describe a complete blockage in one or more of the coronary arteries, which supply oxygenated blood to the heart muscle. This blockage is usually caused by the buildup of fatty deposits, called plaques, inside the artery walls, a condition known as atherosclerosis. Over time, these plaques can rupture, leading to the formation of blood clots that completely obstruct the flow of blood through the coronary artery.

Coronary occlusion can lead to serious complications, such as a heart attack (myocardial infarction), angina (chest pain), or even sudden cardiac death, depending on the severity and duration of the blockage. Immediate medical attention is required in case of coronary occlusion to restore blood flow to the affected areas of the heart and prevent further damage. Treatment options may include medications, minimally invasive procedures like angioplasty and stenting, or surgical interventions such as coronary artery bypass grafting (CABG).

Implanted electrodes are medical devices that are surgically placed inside the body to interface directly with nerves, neurons, or other electrically excitable tissue for various therapeutic purposes. These electrodes can be used to stimulate or record electrical activity from specific areas of the body, depending on their design and application.

There are several types of implanted electrodes, including:

1. Deep Brain Stimulation (DBS) electrodes: These are placed deep within the brain to treat movement disorders such as Parkinson's disease, essential tremor, and dystonia. DBS electrodes deliver electrical impulses that modulate abnormal neural activity in targeted brain regions.
2. Spinal Cord Stimulation (SCS) electrodes: These are implanted along the spinal cord to treat chronic pain syndromes. SCS electrodes emit low-level electrical pulses that interfere with pain signals traveling to the brain, providing relief for patients.
3. Cochlear Implant electrodes: These are surgically inserted into the cochlea of the inner ear to restore hearing in individuals with severe to profound hearing loss. The electrodes stimulate the auditory nerve directly, bypassing damaged hair cells within the cochlea.
4. Retinal Implant electrodes: These are implanted in the retina to treat certain forms of blindness caused by degenerative eye diseases like retinitis pigmentosa. The electrodes convert visual information from a camera into electrical signals, which stimulate remaining retinal cells and transmit the information to the brain via the optic nerve.
5. Sacral Nerve Stimulation (SNS) electrodes: These are placed near the sacral nerves in the lower back to treat urinary or fecal incontinence and overactive bladder syndrome. SNS electrodes deliver electrical impulses that regulate the function of the affected muscles and nerves.
6. Vagus Nerve Stimulation (VNS) electrodes: These are wrapped around the vagus nerve in the neck to treat epilepsy and depression. VNS electrodes provide intermittent electrical stimulation to the vagus nerve, which has connections to various regions of the brain involved in these conditions.

Overall, implanted electrodes serve as a crucial component in many neuromodulation therapies, offering an effective treatment option for numerous neurological and sensory disorders.

Follow-up studies are a type of longitudinal research that involve repeated observations or measurements of the same variables over a period of time, in order to understand their long-term effects or outcomes. In medical context, follow-up studies are often used to evaluate the safety and efficacy of medical treatments, interventions, or procedures.

In a typical follow-up study, a group of individuals (called a cohort) who have received a particular treatment or intervention are identified and then followed over time through periodic assessments or data collection. The data collected may include information on clinical outcomes, adverse events, changes in symptoms or functional status, and other relevant measures.

The results of follow-up studies can provide important insights into the long-term benefits and risks of medical interventions, as well as help to identify factors that may influence treatment effectiveness or patient outcomes. However, it is important to note that follow-up studies can be subject to various biases and limitations, such as loss to follow-up, recall bias, and changes in clinical practice over time, which must be carefully considered when interpreting the results.

Atrial function in a medical context refers to the role and performance of the two upper chambers of the heart, known as the atria. The main functions of the atria are to receive blood from the veins and help pump it into the ventricles, which are the lower pumping chambers of the heart.

The atria contract in response to electrical signals generated by the sinoatrial node, which is the heart's natural pacemaker. This contraction helps to fill the ventricles with blood before they contract and pump blood out to the rest of the body. Atrial function can be assessed through various diagnostic tests, such as echocardiograms or electrocardiograms (ECGs), which can help identify any abnormalities in atrial structure or electrical activity that may affect heart function.

Cardiac resynchronization therapy (CRT) devices are medical implants used to treat heart failure by helping the heart's lower chambers (ventricles) contract more efficiently and in a coordinated manner. These devices combine the functions of a pacemaker and an implantable cardioverter-defibrillator (ICD).

A CRT device has three leads: one that is placed in the right atrium, another in the right ventricle, and a third in the left ventricle through the coronary sinus vein. This configuration allows for simultaneous or near-simultaneous electrical activation of both ventricles, which can improve the heart's pumping efficiency and reduce symptoms associated with heart failure.

There are two main types of CRT devices:

1. Cardiac Resynchronization Therapy-Pacemaker (CRT-P): This device is primarily used to coordinate the contractions of both ventricles through electrical stimulation, using pacing therapy. It is appropriate for patients who do not require defibrillation therapy.
2. Cardiac Resynchronization Therapy-Defibrillator (CRT-D): This device combines the functions of a CRT-P and an ICD, providing both coordinated electrical stimulation and protection against life-threatening ventricular arrhythmias that can lead to sudden cardiac death.

The selection of a CRT device depends on the individual patient's needs and medical history. The primary goal of CRT devices is to improve heart function, reduce symptoms, enhance quality of life, and potentially increase survival in select patients with heart failure.

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

Percutaneous Coronary Intervention (PCI), also known as coronary angioplasty, is a non-surgical procedure that opens up clogged coronary arteries to improve blood flow to the heart. It involves inserting a thin, flexible catheter into an artery in the groin or wrist and guiding it to the blocked artery in the heart. A small balloon is then inflated to widen the narrowed or blocked artery, and sometimes a stent (a tiny mesh tube) is placed to keep the artery open. This procedure helps to restore and maintain blood flow to the heart muscle, reducing symptoms of angina and improving overall cardiac function.

A cardiac catheter is a thin, flexible tube that is inserted into the heart or adjacent blood vessels during a cardiac catheterization procedure. This procedure is typically performed to diagnose and treat various cardiovascular conditions such as heart disease, heart defects, or abnormal heart rhythms.

Cardiac catheters can be used for several purposes:

1. To measure the pressure and oxygen levels in different chambers of the heart and blood vessels.
2. To inject dye into the coronary arteries to visualize blockages or narrowing through angiography.
3. To perform interventions such as balloon angioplasty, stent placement, or valvuloplasty to open up blocked or narrowed blood vessels or repair damaged heart valves.
4. To collect samples of heart muscle tissue for biopsy, which can help diagnose conditions like cardiomyopathy or myocarditis.

There are various types of cardiac catheters, including:

1. Diagnostic catheters - used to measure pressure and oxygen levels in the heart and blood vessels.
2. Guiding catheters - used to guide other interventional devices like balloons or stents into place.
3. Angioplasty balloon catheters - used to inflate a balloon at the tip of the catheter, which helps open up blocked or narrowed blood vessels.
4. Thermodilution catheters - used to measure cardiac output and other hemodynamic parameters.
5. Microcatheters - smaller, more flexible catheters used for complex interventions or accessing difficult-to-reach areas of the heart and blood vessels.

Cardiac catheterization is a minimally invasive procedure that usually requires only local anesthesia and mild sedation. The recovery time is typically short, with most patients returning home within 24 hours after the procedure.

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

Paranasal sinus neoplasms refer to abnormal growths or tumors that develop within the paranasal sinuses, which are air-filled cavities located inside the skull near the nasal cavity. These tumors can be benign (noncancerous) or malignant (cancerous), and they can arise from various types of tissue within the sinuses, such as the lining of the sinuses (mucosa), bone, or other soft tissues.

Paranasal sinus neoplasms can cause a variety of symptoms, including nasal congestion, nosebleeds, facial pain or numbness, and visual disturbances. The diagnosis of these tumors typically involves a combination of imaging studies (such as CT or MRI scans) and biopsy to determine the type and extent of the tumor. Treatment options may include surgery, radiation therapy, chemotherapy, or a combination of these approaches, depending on the specific type and stage of the neoplasm.

Medical Definition:

"Risk factors" are any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury. They can be divided into modifiable and non-modifiable risk factors. Modifiable risk factors are those that can be changed through lifestyle choices or medical treatment, while non-modifiable risk factors are inherent traits such as age, gender, or genetic predisposition. Examples of modifiable risk factors include smoking, alcohol consumption, physical inactivity, and unhealthy diet, while non-modifiable risk factors include age, sex, and family history. It is important to note that having a risk factor does not guarantee that a person will develop the disease, but rather indicates an increased susceptibility.

Phlebography is a medical imaging technique used to visualize and assess the veins, particularly in the legs. It involves the injection of a contrast agent into the veins, followed by X-ray imaging to capture the flow of the contrast material through the veins. This allows doctors to identify any abnormalities such as blood clots, blockages, or malformations in the venous system.

There are different types of phlebography, including ascending phlebography (where the contrast agent is injected into a foot vein and travels up the leg) and descending phlebography (where the contrast agent is injected into a vein in the groin or neck and travels down the leg).

Phlebography is an invasive procedure that requires careful preparation and monitoring, and it is typically performed by radiologists or vascular specialists. It has largely been replaced by non-invasive imaging techniques such as ultrasound and CT angiography in many clinical settings.

Atrioventricular (AV) nodal reentrant tachycardia (AVNRT) is a type of supraventricular tachycardia (SVT), which is a rapid heart rhythm originating at or above the atrioventricular node. In AVNRT, an abnormal electrical circuit in or near the AV node creates a reentry pathway that allows for rapid heart rates, typically greater than 150-250 beats per minute.

In normal conduction, the electrical impulse travels from the atria to the ventricles through the AV node and then continues down the bundle branches to the Purkinje fibers, resulting in a coordinated contraction of the heart. In AVNRT, an extra electrical pathway exists that allows for the reentry of the electrical impulse back into the atria, creating a rapid and abnormal circuit.

AVNRT is classified based on the direction of the reentry circuit:

1. Typical or common AVNRT: The most common form, accounting for 90% of cases. In this type, the reentry circuit involves an "anterior" and a "posterior" loop in or near the AV node. The anterior loop has slower conduction velocity than the posterior loop, creating a "short" reentry circuit that is responsible for the rapid heart rate.
2. Atypical AVNRT: Less common, accounting for 10% of cases. In this type, the reentry circuit involves an "outer" and an "inner" loop around the AV node. The outer loop has slower conduction velocity than the inner loop, creating a "long" reentry circuit that is responsible for the rapid heart rate.

AVNRT can present with symptoms such as palpitations, dizziness, lightheadedness, shortness of breath, chest discomfort, or syncope (fainting). Treatment options include observation, vagal maneuvers, medications, and catheter ablation. Catheter ablation is a curative treatment that involves the destruction of the abnormal electrical pathway using radiofrequency energy or cryotherapy.

The heart ventricles are the two lower chambers of the heart that receive blood from the atria and pump it to the lungs or the rest of the body. The right ventricle pumps deoxygenated blood to the lungs, while the left ventricle pumps oxygenated blood to the rest of the body. Both ventricles have thick, muscular walls to generate the pressure necessary to pump blood through the circulatory system.

Supraventricular tachycardia (SVT) is a rapid heart rhythm that originates above the ventricles (the lower chambers of the heart). This type of tachycardia includes atrial tachycardia, atrioventricular nodal reentrant tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT). SVT usually causes a rapid heartbeat that starts and stops suddenly, and may not cause any other symptoms. However, some people may experience palpitations, shortness of breath, chest discomfort, dizziness, or fainting. SVT is typically diagnosed through an electrocardiogram (ECG) or Holter monitor, and can be treated with medications, cardioversion, or catheter ablation.

Prosthesis implantation is a surgical procedure where an artificial device or component, known as a prosthesis, is placed inside the body to replace a missing or damaged body part. The prosthesis can be made from various materials such as metal, plastic, or ceramic and is designed to perform the same function as the original body part.

The implantation procedure involves making an incision in the skin to create a pocket where the prosthesis will be placed. The prosthesis is then carefully positioned and secured in place using screws, cement, or other fixation methods. In some cases, tissue from the patient's own body may be used to help anchor the prosthesis.

Once the prosthesis is in place, the incision is closed with sutures or staples, and the area is bandaged. The patient will typically need to undergo rehabilitation and physical therapy to learn how to use the new prosthesis and regain mobility and strength.

Prosthesis implantation is commonly performed for a variety of reasons, including joint replacement due to arthritis or injury, dental implants to replace missing teeth, and breast reconstruction after mastectomy. The specific procedure and recovery time will depend on the type and location of the prosthesis being implanted.

The atrial septum is the wall of tissue that divides the right and left atria, which are the upper chambers of the heart. This septum ensures that oxygen-rich blood in the left atrium is kept separate from oxygen-poor blood in the right atrium. Defects or abnormalities in the atrial septum, such as a hole or a gap, can result in various heart conditions, including septal defects and congenital heart diseases.

The sinoatrial (SA) node, also known as the sinus node, is the primary pacemaker of the heart. It is a small bundle of specialized cardiac conduction tissue located in the upper part of the right atrium, near the entrance of the superior vena cava. The SA node generates electrical impulses that initiate each heartbeat, causing the atria to contract and pump blood into the ventricles. This process is called sinus rhythm.

The SA node's electrical activity is regulated by the autonomic nervous system, which can adjust the heart rate in response to changes in the body's needs, such as during exercise or rest. The SA node's rate of firing determines the heart rate, with a normal resting heart rate ranging from 60 to 100 beats per minute.

If the SA node fails to function properly or its electrical impulses are blocked, other secondary pacemakers in the heart may take over, resulting in abnormal heart rhythms called arrhythmias.

Sinus tachycardia is a type of rapid heart rate, characterized by an abnormally fast sinus rhythm, with a rate greater than 100 beats per minute in adults. The sinoatrial node (SA node), which is the natural pacemaker of the heart, generates these impulses regularly and at an increased rate.

Sinus tachycardia is usually a physiological response to various stimuli or conditions, such as physical exertion, strong emotions, fever, anxiety, pain, or certain medications. It can also be caused by hormonal imbalances, anemia, hyperthyroidism, or other medical disorders.

In most cases, sinus tachycardia is not harmful and resolves once the underlying cause is addressed. However, if it occurs persistently or is associated with symptoms like palpitations, shortness of breath, dizziness, or chest discomfort, further evaluation by a healthcare professional is recommended to rule out any underlying heart conditions or other medical issues.

Echocardiography is a medical procedure that uses sound waves to produce detailed images of the heart's structure, function, and motion. It is a non-invasive test that can help diagnose various heart conditions, such as valve problems, heart muscle damage, blood clots, and congenital heart defects.

During an echocardiogram, a transducer (a device that sends and receives sound waves) is placed on the chest or passed through the esophagus to obtain images of the heart. The sound waves produced by the transducer bounce off the heart structures and return to the transducer, which then converts them into electrical signals that are processed to create images of the heart.

There are several types of echocardiograms, including:

* Transthoracic echocardiography (TTE): This is the most common type of echocardiogram and involves placing the transducer on the chest.
* Transesophageal echocardiography (TEE): This type of echocardiogram involves passing a specialized transducer through the esophagus to obtain images of the heart from a closer proximity.
* Stress echocardiography: This type of echocardiogram is performed during exercise or medication-induced stress to assess how the heart functions under stress.
* Doppler echocardiography: This type of echocardiogram uses sound waves to measure blood flow and velocity in the heart and blood vessels.

Echocardiography is a valuable tool for diagnosing and managing various heart conditions, as it provides detailed information about the structure and function of the heart. It is generally safe, non-invasive, and painless, making it a popular choice for doctors and patients alike.

Coronary Care Units (CCUs) are specialized hospital wards that provide intensive care to patients with severe, life-threatening heart conditions. These units are equipped with advanced monitoring and treatment technologies to continuously monitor a patient's cardiac function and provide immediate medical interventions when necessary. Common conditions treated in CCUs include acute myocardial infarction (heart attack), unstable angina, cardiac arrhythmias, and heart failure. The primary goal of a CCU is to stabilize the patient's condition, prevent further complications, and facilitate recovery.

Pathologic dilatation refers to an abnormal and excessive widening or enlargement of a body cavity or organ, which can result from various medical conditions. This abnormal dilation can occur in different parts of the body, including the blood vessels, digestive tract, airways, or heart chambers.

In the context of the cardiovascular system, pathologic dilatation may indicate a weakening or thinning of the heart muscle, leading to an enlarged chamber that can no longer pump blood efficiently. This condition is often associated with various heart diseases, such as cardiomyopathy, valvular heart disease, or long-standing high blood pressure.

In the gastrointestinal tract, pathologic dilatation may occur due to mechanical obstruction, neuromuscular disorders, or inflammatory conditions that affect the normal motility of the intestines. Examples include megacolon in Hirschsprung's disease, toxic megacolon in ulcerative colitis, or volvulus (twisting) of the bowel.

Pathologic dilatation can lead to various complications, such as reduced organ function, impaired circulation, and increased risk of infection or perforation. Treatment depends on the underlying cause and may involve medications, surgery, or other interventions to address the root problem and prevent further enlargement.

Veins are blood vessels that carry deoxygenated blood from the tissues back to the heart. They have a lower pressure than arteries and contain valves to prevent the backflow of blood. Veins have a thin, flexible wall with a larger lumen compared to arteries, allowing them to accommodate more blood volume. The color of veins is often blue or green due to the absorption characteristics of light and the reduced oxygen content in the blood they carry.

Transesophageal echocardiography (TEE) is a type of echocardiogram, which is a medical test that uses sound waves to create detailed images of the heart. In TEE, a special probe containing a transducer is passed down the esophagus (the tube that connects the mouth to the stomach) to obtain views of the heart from behind. This allows for more detailed images of the heart structures and function compared to a standard echocardiogram, which uses a probe placed on the chest. TEE is often used in patients with poor image quality from a standard echocardiogram or when more detailed images are needed to diagnose or monitor certain heart conditions. It is typically performed by a trained cardiologist or sonographer under the direction of a cardiologist.

Wolff-Parkinson-White (WPW) Syndrome is a heart condition characterized by the presence of an accessory pathway or abnormal electrical connection between the atria (the upper chambers of the heart) and ventricles (the lower chambers of the heart). This accessory pathway allows electrical impulses to bypass the normal conduction system, leading to a shorter PR interval and a "delta wave" on the electrocardiogram (ECG), which is the hallmark of WPW Syndrome.

Individuals with WPW Syndrome may experience no symptoms or may have palpitations, rapid heartbeat (tachycardia), or episodes of atrial fibrillation. In some cases, WPW Syndrome can lead to more serious heart rhythm disturbances and may require treatment, such as medication, catheter ablation, or in rare cases, surgery.

It is important to note that not all individuals with WPW Syndrome will experience symptoms or complications, and many people with this condition can lead normal, active lives with appropriate monitoring and management.

Blood flow velocity is the speed at which blood travels through a specific part of the vascular system. It is typically measured in units of distance per time, such as centimeters per second (cm/s) or meters per second (m/s). Blood flow velocity can be affected by various factors, including cardiac output, vessel diameter, and viscosity of the blood. Measuring blood flow velocity is important in diagnosing and monitoring various medical conditions, such as heart disease, stroke, and peripheral vascular disease.

Body Surface Potential Mapping (BSPM) is a non-invasive medical technique used to record and analyze the electrical activity of the heart from the surface of the body. It involves placing multiple electrodes on the skin of the chest, back, and limbs to measure the potential differences between these points during each heartbeat. This information is then used to create a detailed, visual representation of the electrical activation pattern of the heart, which can help in the diagnosis and evaluation of various cardiac disorders such as arrhythmias, myocardial infarction, and ventricular hypertrophy.

The BSPM technique provides high-resolution spatial and temporal information about the cardiac electrical activity, making it a valuable tool for both clinical and research purposes. It can help identify the origin and spread of abnormal electrical signals in the heart, which is crucial for determining appropriate treatment strategies. Overall, Body Surface Potential Mapping is an important diagnostic modality that offers unique insights into the electrical functioning of the heart.

The Predictive Value of Tests, specifically the Positive Predictive Value (PPV) and Negative Predictive Value (NPV), are measures used in diagnostic tests to determine the probability that a positive or negative test result is correct.

Positive Predictive Value (PPV) is the proportion of patients with a positive test result who actually have the disease. It is calculated as the number of true positives divided by the total number of positive results (true positives + false positives). A higher PPV indicates that a positive test result is more likely to be a true positive, and therefore the disease is more likely to be present.

Negative Predictive Value (NPV) is the proportion of patients with a negative test result who do not have the disease. It is calculated as the number of true negatives divided by the total number of negative results (true negatives + false negatives). A higher NPV indicates that a negative test result is more likely to be a true negative, and therefore the disease is less likely to be present.

The predictive value of tests depends on the prevalence of the disease in the population being tested, as well as the sensitivity and specificity of the test. A test with high sensitivity and specificity will generally have higher predictive values than a test with low sensitivity and specificity. However, even a highly sensitive and specific test can have low predictive values if the prevalence of the disease is low in the population being tested.

Fluoroscopy is a type of medical imaging that uses X-rays to obtain real-time moving images of the internal structures of the body. A continuous X-ray beam is passed through the body part being examined, and the resulting fluoroscopic images are transmitted to a monitor, allowing the medical professional to view the structure and movement of the internal organs and bones in real time.

Fluoroscopy is often used to guide minimally invasive procedures such as catheterization, stent placement, or joint injections. It can also be used to diagnose and monitor a variety of medical conditions, including gastrointestinal disorders, musculoskeletal injuries, and cardiovascular diseases.

It is important to note that fluoroscopy involves exposure to ionizing radiation, and the risks associated with this exposure should be carefully weighed against the benefits of the procedure. Medical professionals are trained to use the lowest possible dose of radiation necessary to obtain the desired diagnostic information.

A feasibility study is a preliminary investigation or analysis conducted to determine the viability of a proposed project, program, or product. In the medical field, feasibility studies are often conducted before implementing new treatments, procedures, equipment, or facilities. These studies help to assess the practicality and effectiveness of the proposed intervention, as well as its potential benefits and risks.

Feasibility studies in healthcare typically involve several steps:

1. Problem identification: Clearly define the problem that the proposed project, program, or product aims to address.
2. Objectives setting: Establish specific, measurable, achievable, relevant, and time-bound (SMART) objectives for the study.
3. Literature review: Conduct a thorough review of existing research and best practices related to the proposed intervention.
4. Methodology development: Design a methodology for data collection and analysis that will help answer the research questions and achieve the study's objectives.
5. Resource assessment: Evaluate the availability and adequacy of resources, including personnel, time, and finances, required to carry out the proposed intervention.
6. Risk assessment: Identify potential risks and challenges associated with the implementation of the proposed intervention and develop strategies to mitigate them.
7. Cost-benefit analysis: Estimate the costs and benefits of the proposed intervention, including direct and indirect costs, as well as short-term and long-term benefits.
8. Stakeholder engagement: Engage relevant stakeholders, such as patients, healthcare providers, administrators, and policymakers, to gather their input and support for the proposed intervention.
9. Decision-making: Based on the findings of the feasibility study, make an informed decision about whether or not to proceed with the proposed project, program, or product.

Feasibility studies are essential in healthcare as they help ensure that resources are allocated efficiently and effectively, and that interventions are evidence-based, safe, and beneficial for patients.

A stent is a small mesh tube that's used to treat narrow or weak arteries. Arteries are blood vessels that carry blood away from your heart to other parts of your body. A stent is placed in an artery as part of a procedure called angioplasty. Angioplasty restores blood flow through narrowed or blocked arteries by inflating a tiny balloon inside the blocked artery to widen it.

The stent is then inserted into the widened artery to keep it open. The stent is usually made of metal, but some are coated with medication that is slowly and continuously released to help prevent the formation of scar tissue in the artery. This can reduce the chance of the artery narrowing again.

Stents are also used in other parts of the body, such as the neck (carotid artery) and kidneys (renal artery), to help maintain blood flow and prevent blockages. They can also be used in the urinary system to treat conditions like ureteropelvic junction obstruction or narrowing of the urethra.

Heart failure is a pathophysiological state in which the heart is unable to pump sufficient blood to meet the metabolic demands of the body or do so only at the expense of elevated filling pressures. It can be caused by various cardiac disorders, including coronary artery disease, hypertension, valvular heart disease, cardiomyopathy, and arrhythmias. Symptoms may include shortness of breath, fatigue, and fluid retention. Heart failure is often classified based on the ejection fraction (EF), which is the percentage of blood that is pumped out of the left ventricle during each contraction. A reduced EF (less than 40%) is indicative of heart failure with reduced ejection fraction (HFrEF), while a preserved EF (greater than or equal to 50%) is indicative of heart failure with preserved ejection fraction (HFpEF). There is also a category of heart failure with mid-range ejection fraction (HFmrEF) for those with an EF between 40-49%.

Paroxysmal Tachycardia is a type of arrhythmia (abnormal heart rhythm) characterized by rapid and abrupt onset and offset of episodes of tachycardia, which are faster than normal heart rates. The term "paroxysmal" refers to the sudden and recurring nature of these episodes.

Paroxysmal Tachycardia can occur in various parts of the heart, including the atria (small upper chambers) or ventricles (larger lower chambers). The two most common types are Atrial Paroxysmal Tachycardia (APT) and Ventricular Paroxysmal Tachycardia (VPT).

APT is more common and typically results in a rapid heart rate of 100-250 beats per minute. It usually begins and ends suddenly, lasting for seconds to hours. APT can cause symptoms such as palpitations, lightheadedness, shortness of breath, chest discomfort, or anxiety.

VPT is less common but more serious because it involves the ventricles, which are responsible for pumping blood to the rest of the body. VPT can lead to decreased cardiac output and potentially life-threatening conditions such as syncope (fainting) or even cardiac arrest.

Treatment options for Paroxysmal Tachycardia depend on the underlying cause, severity, and frequency of symptoms. These may include lifestyle modifications, medications, cardioversion (electrical shock to restore normal rhythm), catheter ablation (destroying problematic heart tissue), or implantable devices such as pacemakers or defibrillators.

Maxillary sinus neoplasms refer to abnormal growths or tumors that develop in the maxillary sinuses, which are located in the upper part of your cheekbones, below your eyes. These growths can be benign (non-cancerous) or malignant (cancerous).

Benign neoplasms may include conditions such as an osteoma (a benign bone tumor), a papilloma (a benign growth of the lining of the sinus), or a fibrous dysplasia (a condition where bone is replaced by fibrous tissue).

Malignant neoplasms, on the other hand, can be primary (originating in the maxillary sinuses) or secondary (spreading to the maxillary sinuses from another site in the body). Common types of malignant tumors that arise in the maxillary sinus include squamous cell carcinoma, adenocarcinoma, and mucoepidermoid carcinoma.

Symptoms of maxillary sinus neoplasms may include nasal congestion, nosebleeds, facial pain or numbness, vision changes, and difficulty swallowing or speaking. Treatment options depend on the type, size, and location of the tumor but may include surgery, radiation therapy, chemotherapy, or a combination of these approaches.

Vasodilator agents are pharmacological substances that cause the relaxation or widening of blood vessels by relaxing the smooth muscle in the vessel walls. This results in an increase in the diameter of the blood vessels, which decreases vascular resistance and ultimately reduces blood pressure. Vasodilators can be further classified based on their site of action:

1. Systemic vasodilators: These agents cause a generalized relaxation of the smooth muscle in the walls of both arteries and veins, resulting in a decrease in peripheral vascular resistance and preload (the volume of blood returning to the heart). Examples include nitroglycerin, hydralazine, and calcium channel blockers.
2. Arterial vasodilators: These agents primarily affect the smooth muscle in arterial vessel walls, leading to a reduction in afterload (the pressure against which the heart pumps blood). Examples include angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and direct vasodilators like sodium nitroprusside.
3. Venous vasodilators: These agents primarily affect the smooth muscle in venous vessel walls, increasing venous capacitance and reducing preload. Examples include nitroglycerin and other organic nitrates.

Vasodilator agents are used to treat various cardiovascular conditions such as hypertension, heart failure, angina, and pulmonary arterial hypertension. It is essential to monitor their use carefully, as excessive vasodilation can lead to orthostatic hypotension, reflex tachycardia, or fluid retention.

Blood pressure is the force exerted by circulating blood on the walls of the blood vessels. It is measured in millimeters of mercury (mmHg) and is given as two figures:

1. Systolic pressure: This is the pressure when the heart pushes blood out into the arteries.
2. Diastolic pressure: This is the pressure when the heart rests between beats, allowing it to fill with blood.

Normal blood pressure for adults is typically around 120/80 mmHg, although this can vary slightly depending on age, sex, and other factors. High blood pressure (hypertension) is generally considered to be a reading of 130/80 mmHg or higher, while low blood pressure (hypotension) is usually defined as a reading below 90/60 mmHg. It's important to note that blood pressure can fluctuate throughout the day and may be affected by factors such as stress, physical activity, and medication use.

The heart septum is the thick, muscular wall that divides the right and left sides of the heart. It consists of two main parts: the atrial septum, which separates the right and left atria (the upper chambers of the heart), and the ventricular septum, which separates the right and left ventricles (the lower chambers of the heart). A normal heart septum ensures that oxygen-rich blood from the lungs does not mix with oxygen-poor blood from the body. Any defect or abnormality in the heart septum is called a septal defect, which can lead to various congenital heart diseases.

Oxygen consumption, also known as oxygen uptake, is the amount of oxygen that is consumed or utilized by the body during a specific period of time, usually measured in liters per minute (L/min). It is a common measurement used in exercise physiology and critical care medicine to assess an individual's aerobic metabolism and overall health status.

In clinical settings, oxygen consumption is often measured during cardiopulmonary exercise testing (CPET) to evaluate cardiovascular function, pulmonary function, and exercise capacity in patients with various medical conditions such as heart failure, chronic obstructive pulmonary disease (COPD), and other respiratory or cardiac disorders.

During exercise, oxygen is consumed by the muscles to generate energy through a process called oxidative phosphorylation. The amount of oxygen consumed during exercise can provide important information about an individual's fitness level, exercise capacity, and overall health status. Additionally, measuring oxygen consumption can help healthcare providers assess the effectiveness of treatments and rehabilitation programs in patients with various medical conditions.

Cardiopulmonary bypass (CPB) is a medical procedure that temporarily takes over the functions of the heart and lungs during major heart surgery. It allows the surgeon to operate on a still, bloodless heart.

During CPB, the patient's blood is circulated outside the body with the help of a heart-lung machine. The machine pumps the blood through a oxygenator, where it is oxygenated and then returned to the body. This bypasses the heart and lungs, hence the name "cardiopulmonary bypass."

CPB involves several components, including a pump, oxygenator, heat exchanger, and tubing. The patient's blood is drained from the heart through cannulas (tubes) and passed through the oxygenator, where it is oxygenated and carbon dioxide is removed. The oxygenated blood is then warmed to body temperature in a heat exchanger before being pumped back into the body.

While on CPB, the patient's heart is stopped with the help of cardioplegia solution, which is infused directly into the coronary arteries. This helps to protect the heart muscle during surgery. The surgeon can then operate on a still and bloodless heart, allowing for more precise surgical repair.

After the surgery is complete, the patient is gradually weaned off CPB, and the heart is restarted with the help of electrical stimulation or medication. The patient's condition is closely monitored during this time to ensure that their heart and lungs are functioning properly.

While CPB has revolutionized heart surgery and allowed for more complex procedures to be performed, it is not without risks. These include bleeding, infection, stroke, kidney damage, and inflammation. However, with advances in technology and technique, the risks associated with CPB have been significantly reduced over time.

An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. This connection causes blood to flow directly from the artery into the vein, bypassing the capillary network that would normally distribute the oxygen-rich blood to the surrounding tissues.

Arteriovenous fistulas can occur as a result of trauma, disease, or as a planned surgical procedure for patients who require hemodialysis, a treatment for advanced kidney failure. In hemodialysis, the arteriovenous fistula serves as a site for repeated access to the bloodstream, allowing for efficient removal of waste products and excess fluids.

The medical definition of an arteriovenous fistula is:

"An abnormal communication between an artery and a vein, usually created by surgical means for hemodialysis access or occurring as a result of trauma, congenital defects, or disease processes such as vasculitis or neoplasm."

The mitral valve, also known as the bicuspid valve, is a two-leaflet valve located between the left atrium and left ventricle in the heart. Its function is to ensure unidirectional flow of blood from the left atrium into the left ventricle during the cardiac cycle. The mitral valve consists of two leaflets (anterior and posterior), the chordae tendineae, papillary muscles, and the left atrial and ventricular myocardium. Dysfunction of the mitral valve can lead to various heart conditions such as mitral regurgitation or mitral stenosis.

Pulmonary veins are blood vessels that carry oxygenated blood from the lungs to the left atrium of the heart. There are four pulmonary veins in total, two from each lung, and they are the only veins in the body that carry oxygen-rich blood. The oxygenated blood from the pulmonary veins is then pumped by the left ventricle to the rest of the body through the aorta. Any blockage or damage to the pulmonary veins can lead to various cardiopulmonary conditions, such as pulmonary hypertension and congestive heart failure.

Adenosine is a purine nucleoside that is composed of a sugar (ribose) and the base adenine. It plays several important roles in the body, including serving as a precursor for the synthesis of other molecules such as ATP, NAD+, and RNA.

In the medical context, adenosine is perhaps best known for its use as a pharmaceutical agent to treat certain cardiac arrhythmias. When administered intravenously, it can help restore normal sinus rhythm in patients with paroxysmal supraventricular tachycardia (PSVT) by slowing conduction through the atrioventricular node and interrupting the reentry circuit responsible for the arrhythmia.

Adenosine can also be used as a diagnostic tool to help differentiate between narrow-complex tachycardias of supraventricular origin and those that originate from below the ventricles (such as ventricular tachycardia). This is because adenosine will typically terminate PSVT but not affect the rhythm of VT.

It's worth noting that adenosine has a very short half-life, lasting only a few seconds in the bloodstream. This means that its effects are rapidly reversible and generally well-tolerated, although some patients may experience transient symptoms such as flushing, chest pain, or shortness of breath.

Tachycardia is a heart rate that is faster than normal when resting. In adults, a normal resting heart rate is typically between 60 and 100 beats per minute (bpm). Tachycardia is generally considered to be a heart rate of more than 100 bpm.

Ectopic atrial tachycardia (EAT) is a type of supraventricular tachycardia (SVT), which means that the abnormal rapid heartbeats originate in the atria, the upper chambers of the heart. EAT is caused by an ectopic focus, or an abnormal electrical focus outside of the sinoatrial node (the heart's natural pacemaker). This ectopic focus can be located in one of the pulmonary veins or in other atrial tissue.

EAT may present with symptoms such as palpitations, lightheadedness, shortness of breath, chest discomfort, or syncope (fainting). In some cases, EAT may not cause any symptoms and can be an incidental finding on an electrocardiogram (ECG) or Holter monitor.

The diagnosis of EAT is typically made based on the ECG findings, which show a regular narrow QRS complex tachycardia with P waves that are inverted in the inferior leads and often dissociated from the QRS complexes. Treatment options for EAT include observation, pharmacologic therapy, cardioversion, or catheter ablation.

Heart block is a cardiac condition characterized by the interruption of electrical impulse transmission from the atria (the upper chambers of the heart) to the ventricles (the lower chambers of the heart). This disruption can lead to abnormal heart rhythms, including bradycardia (a slower-than-normal heart rate), and in severe cases, can cause the heart to stop beating altogether. Heart block is typically caused by damage to the heart's electrical conduction system due to various factors such as aging, heart disease, or certain medications.

There are three types of heart block: first-degree, second-degree, and third-degree (also known as complete heart block). Each type has distinct electrocardiogram (ECG) findings and symptoms. Treatment for heart block depends on the severity of the condition and may include monitoring, medication, or implantation of a pacemaker to regulate the heart's electrical activity.

Electric countershock, also known as defibrillation, is a medical procedure that uses an electric current to restore normal heart rhythm in certain types of cardiac arrhythmias, such as ventricular fibrillation or pulseless ventricular tachycardia. The procedure involves delivering a therapeutic dose of electrical energy to the heart through electrodes placed on the chest wall or directly on the heart. This electric current helps to depolarize a large number of cardiac cells simultaneously, which can help to interrupt the abnormal electrical activity in the heart and allow the normal conduction system to regain control and restore a normal rhythm. Electric countershock is typically delivered using an automated external defibrillator (AED) or a manual defibrillator, and it is a critical component of advanced cardiac life support (ACLS).

Microvascular angina, also known as cardiac syndrome X or microvascular ischemia, is a type of angina (chest pain) that results from reduced blood flow to the heart muscle due to dysfunction in the small coronary arteries (microvasculature). These vessels are too small to be visualized during conventional diagnostic tests like coronary angiography.

The medical definition of microvascular angina is:

A clinical syndrome characterized by the presence of anginal chest pain, often accompanied by evidence of myocardial ischemia (insufficient blood flow to the heart muscle), in the absence of obstructive coronary artery disease on conventional diagnostic imaging. The underlying mechanism involves dysfunction and impaired regulation of the microvasculature, leading to reduced vasodilatory capacity, increased vasoconstriction, and ultimately, inadequate oxygen supply to meet the metabolic demands of the heart muscle.

Microvascular angina is more prevalent in women, especially those with risk factors such as hypertension, diabetes, hyperlipidemia, and smoking. Diagnosis often requires specialized testing like coronary flow reserve assessment using positron emission tomography (PET) or cardiac magnetic resonance imaging (MRI). Treatment typically involves a combination of lifestyle modifications, medications to improve blood vessel function and reduce chest pain, and sometimes, invasive treatments such as transmyocardial laser revascularization.

Cardiac surgical procedures are operations that are performed on the heart or great vessels (the aorta and vena cava) by cardiothoracic surgeons. These surgeries are often complex and require a high level of skill and expertise. Some common reasons for cardiac surgical procedures include:

1. Coronary artery bypass grafting (CABG): This is a surgery to improve blood flow to the heart in patients with coronary artery disease. During the procedure, a healthy blood vessel from another part of the body is used to create a detour around the blocked or narrowed portion of the coronary artery.
2. Valve repair or replacement: The heart has four valves that control blood flow through and out of the heart. If one or more of these valves become damaged or diseased, they may need to be repaired or replaced. This can be done using artificial valves or valves from animal or human donors.
3. Aneurysm repair: An aneurysm is a weakened area in the wall of an artery that can bulge out and potentially rupture. If an aneurysm occurs in the aorta, it may require surgical repair to prevent rupture.
4. Heart transplantation: In some cases, heart failure may be so severe that a heart transplant is necessary. This involves removing the diseased heart and replacing it with a healthy donor heart.
5. Arrhythmia surgery: Certain types of abnormal heart rhythms (arrhythmias) may require surgical treatment. One such procedure is called the Maze procedure, which involves creating a pattern of scar tissue in the heart to disrupt the abnormal electrical signals that cause the arrhythmia.
6. Congenital heart defect repair: Some people are born with structural problems in their hearts that require surgical correction. These may include holes between the chambers of the heart or abnormal blood vessels.

Cardiac surgical procedures carry risks, including bleeding, infection, stroke, and death. However, for many patients, these surgeries can significantly improve their quality of life and longevity.

Dipyridamole is a medication that belongs to a class of drugs called antiplatelet agents. It works by preventing platelets in your blood from sticking together to form clots. Dipyridamole is often used in combination with aspirin to prevent stroke and other complications in people who have had a heart valve replacement or a type of irregular heartbeat called atrial fibrillation.

Dipyridamole can also be used as a stress agent in myocardial perfusion imaging studies, which are tests used to evaluate blood flow to the heart. When used for this purpose, dipyridamole is given intravenously and works by dilating the blood vessels in the heart, allowing more blood to flow through them and making it easier to detect areas of reduced blood flow.

The most common side effects of dipyridamole include headache, dizziness, and gastrointestinal symptoms such as diarrhea, nausea, and vomiting. In rare cases, dipyridamole can cause more serious side effects, such as allergic reactions, abnormal heart rhythms, or low blood pressure. It is important to take dipyridamole exactly as directed by your healthcare provider and to report any unusual symptoms or side effects promptly.

A pilonidal sinus is a small hole or tunnel in the skin that usually develops in the cleft at the top of the buttocks. It can be painful and may become infected, causing symptoms such as redness, swelling, pain, and pus discharge. The condition often affects young adults and is more common in men than women.

The term "pilonidal" comes from the Latin words "pilus," meaning hair, and "nidus," meaning nest. This refers to the fact that the sinus often contains hairs that have become embedded in the skin. The exact cause of pilonidal sinuses is not known, but they are thought to develop as a result of ingrown hairs or chronic irritation in the affected area.

Treatment for pilonidal sinuses typically involves surgical removal of the sinus and any associated hair follicles. In some cases, this may be done using a minor procedure that can be performed in a doctor's office. More complex cases may require hospitalization and a more extensive surgical procedure. After surgery, patients will need to take steps to prevent the sinus from recurring, such as keeping the area clean and avoiding prolonged periods of sitting or driving.

Equipment design, in the medical context, refers to the process of creating and developing medical equipment and devices, such as surgical instruments, diagnostic machines, or assistive technologies. This process involves several stages, including:

1. Identifying user needs and requirements
2. Concept development and brainstorming
3. Prototyping and testing
4. Design for manufacturing and assembly
5. Safety and regulatory compliance
6. Verification and validation
7. Training and support

The goal of equipment design is to create safe, effective, and efficient medical devices that meet the needs of healthcare providers and patients while complying with relevant regulations and standards. The design process typically involves a multidisciplinary team of engineers, clinicians, designers, and researchers who work together to develop innovative solutions that improve patient care and outcomes.

Retrospective studies, also known as retrospective research or looking back studies, are a type of observational study that examines data from the past to draw conclusions about possible causal relationships between risk factors and outcomes. In these studies, researchers analyze existing records, medical charts, or previously collected data to test a hypothesis or answer a specific research question.

Retrospective studies can be useful for generating hypotheses and identifying trends, but they have limitations compared to prospective studies, which follow participants forward in time from exposure to outcome. Retrospective studies are subject to biases such as recall bias, selection bias, and information bias, which can affect the validity of the results. Therefore, retrospective studies should be interpreted with caution and used primarily to generate hypotheses for further testing in prospective studies.

A fistula is an abnormal connection or passage between two organs, vessels, or body parts that usually do not connect. It can form as a result of injury, infection, surgery, or disease. A fistula can occur anywhere in the body but commonly forms in the digestive system, genital area, or urinary system. The symptoms and treatment options for a fistula depend on its location and underlying cause.

Cardiac Resynchronization Therapy (CRT) is a medical treatment for heart failure that involves the use of a specialized device, called a biventricular pacemaker or a cardiac resynchronization therapy device, to help coordinate the timing of contractions between the left and right ventricles of the heart.

In a healthy heart, the ventricles contract in a coordinated manner, with the left ventricle contracting slightly before the right ventricle. However, in some people with heart failure, the electrical signals that control the contraction of the heart become disrupted, causing the ventricles to contract at different times. This is known as ventricular dyssynchrony and can lead to reduced pumping efficiency and further worsening of heart failure symptoms.

CRT works by delivering small electrical impulses to both ventricles simultaneously or in a coordinated manner, which helps restore normal synchrony and improve the efficiency of the heart's pumping function. This can lead to improved symptoms, reduced hospitalizations, and increased survival rates in some people with heart failure.

CRT is typically recommended for people with moderate to severe heart failure who have evidence of ventricular dyssynchrony and a wide QRS complex on an electrocardiogram (ECG). The procedure involves the implantation of a small device under the skin, usually in the upper chest area, which is connected to leads that are placed in the heart through veins.

While CRT can be an effective treatment for some people with heart failure, it is not without risks and potential complications, such as infection, bleeding, or damage to blood vessels or nerves. Therefore, careful consideration should be given to the potential benefits and risks of CRT before deciding whether it is appropriate for a particular individual.

Vascular resistance is a measure of the opposition to blood flow within a vessel or a group of vessels, typically expressed in units of mmHg/(mL/min) or sometimes as dynes*sec/cm^5. It is determined by the diameter and length of the vessels, as well as the viscosity of the blood flowing through them. In general, a decrease in vessel diameter, an increase in vessel length, or an increase in blood viscosity will result in an increase in vascular resistance, while an increase in vessel diameter, a decrease in vessel length, or a decrease in blood viscosity will result in a decrease in vascular resistance. Vascular resistance is an important concept in the study of circulation and cardiovascular physiology because it plays a key role in determining blood pressure and blood flow within the body.

Left ventricular function refers to the ability of the left ventricle (the heart's lower-left chamber) to contract and relax, thereby filling with and ejecting blood. The left ventricle is responsible for pumping oxygenated blood to the rest of the body. Its function is evaluated by measuring several parameters, including:

1. Ejection fraction (EF): This is the percentage of blood that is pumped out of the left ventricle with each heartbeat. A normal ejection fraction ranges from 55% to 70%.
2. Stroke volume (SV): The amount of blood pumped by the left ventricle in one contraction. A typical SV is about 70 mL/beat.
3. Cardiac output (CO): The total volume of blood that the left ventricle pumps per minute, calculated as the product of stroke volume and heart rate. Normal CO ranges from 4 to 8 L/minute.

Assessment of left ventricular function is crucial in diagnosing and monitoring various cardiovascular conditions such as heart failure, coronary artery disease, valvular heart diseases, and cardiomyopathies.

Tachycardia is a medical term that refers to an abnormally rapid heart rate, often defined as a heart rate greater than 100 beats per minute in adults. It can occur in either the atria (upper chambers) or ventricles (lower chambers) of the heart. Different types of tachycardia include supraventricular tachycardia (SVT), atrial fibrillation, atrial flutter, and ventricular tachycardia.

Tachycardia can cause various symptoms such as palpitations, shortness of breath, dizziness, lightheadedness, chest discomfort, or syncope (fainting). In some cases, tachycardia may not cause any symptoms and may only be detected during a routine physical examination or medical test.

The underlying causes of tachycardia can vary widely, including heart disease, electrolyte imbalances, medications, illicit drug use, alcohol abuse, smoking, stress, anxiety, and other medical conditions. In some cases, the cause may be unknown. Treatment for tachycardia depends on the underlying cause, type, severity, and duration of the arrhythmia.

Interventional ultrasonography is a medical procedure that involves the use of real-time ultrasound imaging to guide minimally invasive diagnostic and therapeutic interventions. This technique combines the advantages of ultrasound, such as its non-ionizing nature (no radiation exposure), relatively low cost, and portability, with the ability to perform precise and targeted procedures.

In interventional ultrasonography, a specialized physician called an interventional radiologist or an interventional sonographer uses high-frequency sound waves to create detailed images of internal organs and tissues. These images help guide the placement of needles, catheters, or other instruments used during the procedure. Common interventions include biopsies (tissue sampling), fluid drainage, tumor ablation, and targeted drug delivery.

The real-time visualization provided by ultrasonography allows for increased accuracy and safety during these procedures, minimizing complications and reducing recovery time compared to traditional surgical approaches. Additionally, interventional ultrasonography can be performed on an outpatient basis, further contributing to its appeal as a less invasive alternative in many clinical scenarios.

Extracorporeal circulation (ECC) is a term used in medicine to describe the process of temporarily taking over the functions of the heart and lungs by using a machine. This allows the surgeon to perform certain types of surgery, such as open-heart surgery, on a still and bloodless operating field.

During ECC, the patient's blood is circulated outside the body through a pump and oxygenator. The pump helps to maintain blood flow and pressure, while the oxygenator adds oxygen to the blood and removes carbon dioxide. This allows the surgeon to stop the heart and arrest its motion, making it easier to perform delicate procedures on the heart and surrounding structures.

Extracorporeal circulation is a complex and high-risk procedure that requires careful monitoring and management by a team of healthcare professionals. It carries risks such as bleeding, infection, and injury to blood vessels or organs. However, when performed correctly, it can be a life-saving measure for patients undergoing certain types of surgery.

Collateral circulation refers to the alternate blood supply routes that bypass an obstructed or narrowed vessel and reconnect with the main vascular system. These collateral vessels can develop over time as a result of the body's natural adaptation to chronic ischemia (reduced blood flow) caused by various conditions such as atherosclerosis, thromboembolism, or vasculitis.

The development of collateral circulation helps maintain adequate blood flow and oxygenation to affected tissues, minimizing the risk of tissue damage and necrosis. In some cases, well-developed collateral circulations can help compensate for significant blockages in major vessels, reducing symptoms and potentially preventing the need for invasive interventions like revascularization procedures. However, the extent and effectiveness of collateral circulation vary from person to person and depend on factors such as age, overall health status, and the presence of comorbidities.

Stable angina is a type of chest pain or discomfort that typically occurs during physical exertion or emotional stress. It is caused by reduced blood flow to the heart muscle, which can occur when the coronary arteries become narrowed or blocked due to the buildup of cholesterol and other substances (a condition known as atherosclerosis).

The symptoms of stable angina are usually predictable and may include chest pain or discomfort that is:

* Described as a squeezing, pressure, heaviness, or tightness in the chest
* Typically located in the center of the chest, but may radiate to the shoulders, arms, neck, jaw, or back
* Lasts for a few minutes and is usually relieved by rest or nitroglycerin

Stable angina is considered "stable" because the symptoms tend to occur predictably and can be managed with medication, lifestyle changes, and sometimes medical procedures such as angioplasty or bypass surgery. However, it is still a serious condition that requires proper diagnosis and treatment to prevent complications such as heart attack or stroke.

Recurrence, in a medical context, refers to the return of symptoms or signs of a disease after a period of improvement or remission. It indicates that the condition has not been fully eradicated and may require further treatment. Recurrence is often used to describe situations where a disease such as cancer comes back after initial treatment, but it can also apply to other medical conditions. The likelihood of recurrence varies depending on the type of disease and individual patient factors.

Mitral valve annuloplasty is a surgical procedure that involves repairing and reinforcing the mitral valve in the heart, which helps control blood flow between the left atrium and left ventricle. The procedure typically aims to reduce the size of the mitral valve's dilated or stretched opening (annulus) by implanting a prosthetic ring or band around it. This reinforcement helps restore normal valve function, preventing regurgitation or backflow of blood into the atrium during heart contractions.

The procedure is often performed to treat mitral valve regurgitation, which can be caused by various factors such as age-related degenerative changes, infective endocarditis, rheumatic heart disease, or congenital abnormalities. Mitral valve annuloplasty may be done alone or in combination with other cardiac surgeries like mitral valve replacement or repair of the valve leaflets.

Vasodilation is the widening or increase in diameter of blood vessels, particularly the involuntary relaxation of the smooth muscle in the tunica media (middle layer) of the arteriole walls. This results in an increase in blood flow and a decrease in vascular resistance. Vasodilation can occur due to various physiological and pathophysiological stimuli, such as local metabolic demands, neural signals, or pharmacological agents. It plays a crucial role in regulating blood pressure, tissue perfusion, and thermoregulation.

The transverse sinuses are a pair of venous channels located within the skull. They are part of the intracranial venous system and are responsible for draining blood from the brain. The transverse sinuses run horizontally along the upper portion of the inner skull, starting at the occipital bone (at the back of the head) and extending to the temporal bones (on the sides of the head).

These sinuses receive blood from the superior sagittal sinus, straight sinus, and the occipital sinus. After passing through the transverse sinuses, the blood is then drained into the sigmoid sinuses, which in turn drain into the internal jugular veins. The transverse sinuses are an essential component of the cerebral venous system, ensuring proper blood flow and drainage from the brain.

Calcinosis is a medical condition characterized by the abnormal deposit of calcium salts in various tissues of the body, commonly under the skin or in the muscles and tendons. These calcium deposits can form hard lumps or nodules that can cause pain, inflammation, and restricted mobility. Calcinosis can occur as a complication of other medical conditions, such as autoimmune disorders, kidney disease, and hypercalcemia (high levels of calcium in the blood). In some cases, the cause of calcinosis may be unknown. Treatment for calcinosis depends on the underlying cause and may include medications to manage calcium levels, physical therapy, and surgical removal of large deposits.

Heart rate is the number of heartbeats per unit of time, often expressed as beats per minute (bpm). It can vary significantly depending on factors such as age, physical fitness, emotions, and overall health status. A resting heart rate between 60-100 bpm is generally considered normal for adults, but athletes and individuals with high levels of physical fitness may have a resting heart rate below 60 bpm due to their enhanced cardiovascular efficiency. Monitoring heart rate can provide valuable insights into an individual's health status, exercise intensity, and response to various treatments or interventions.

Left ventricular dysfunction (LVD) is a condition characterized by the impaired ability of the left ventricle of the heart to pump blood efficiently during contraction. The left ventricle is one of the four chambers of the heart and is responsible for pumping oxygenated blood to the rest of the body.

LVD can be caused by various underlying conditions, such as coronary artery disease, cardiomyopathy, valvular heart disease, or hypertension. These conditions can lead to structural changes in the left ventricle, including remodeling, hypertrophy, and dilation, which ultimately impair its contractile function.

The severity of LVD is often assessed by measuring the ejection fraction (EF), which is the percentage of blood that is pumped out of the left ventricle during each contraction. A normal EF ranges from 55% to 70%, while an EF below 40% is indicative of LVD.

LVD can lead to various symptoms, such as shortness of breath, fatigue, fluid retention, and decreased exercise tolerance. It can also increase the risk of complications, such as heart failure, arrhythmias, and cardiac arrest. Treatment for LVD typically involves managing the underlying cause, along with medications to improve contractility, reduce fluid buildup, and control heart rate. In severe cases, devices such as implantable cardioverter-defibrillators (ICDs) or left ventricular assist devices (LVADs) may be required.

Coronary artery bypass, off-pump refers to a surgical procedure used to treat coronary artery disease (CAD), which is the narrowing or blockage of the coronary arteries due to the buildup of fatty deposits called plaques. This procedure is also known as off-pump coronary artery bypass (OPCAB) or beating heart bypass surgery.

In a coronary artery bypass, off-pump procedure, the surgeon creates a new pathway for blood to flow around the blocked or narrowed portion of the coronary artery using a healthy blood vessel from another part of the body, such as the chest wall (internal mammary artery) or the leg (saphenous vein). This allows oxygen-rich blood to bypass the blockage and reach the heart muscle directly.

The key difference between on-pump and off-pump coronary artery bypass surgery is that in an off-pump procedure, the heart continues to beat during the operation, and no heart-lung machine (cardiopulmonary bypass) is used. This approach has several potential advantages over on-pump CABG, including reduced risks of bleeding, stroke, and kidney failure. However, it may not be suitable for all patients, particularly those with complex or extensive coronary artery disease.

Overall, coronary artery bypass, off-pump surgery is a safe and effective treatment option for many patients with CAD, and can help improve symptoms, quality of life, and long-term outcomes.

A vascular fistula is an abnormal connection or passage between the artery and vein, which usually results from a surgical procedure to create access for hemodialysis in patients with chronic kidney disease. This communication allows blood to flow directly from the artery into the vein, bypassing the capillary network and causing high-flow conditions in the affected area. Over time, the increased pressure and flow can lead to various complications such as venous hypertension, stenosis, aneurysm formation, or even heart failure if left untreated. Vascular fistulas may also occur spontaneously due to certain medical conditions like vasculitis, trauma, or infection, although this is less common.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

A Severity of Illness Index is a measurement tool used in healthcare to assess the severity of a patient's condition and the risk of mortality or other adverse outcomes. These indices typically take into account various physiological and clinical variables, such as vital signs, laboratory values, and co-morbidities, to generate a score that reflects the patient's overall illness severity.

Examples of Severity of Illness Indices include the Acute Physiology and Chronic Health Evaluation (APACHE) system, the Simplified Acute Physiology Score (SAPS), and the Mortality Probability Model (MPM). These indices are often used in critical care settings to guide clinical decision-making, inform prognosis, and compare outcomes across different patient populations.

It is important to note that while these indices can provide valuable information about a patient's condition, they should not be used as the sole basis for clinical decision-making. Rather, they should be considered in conjunction with other factors, such as the patient's overall clinical presentation, treatment preferences, and goals of care.

Risk assessment in the medical context refers to the process of identifying, evaluating, and prioritizing risks to patients, healthcare workers, or the community related to healthcare delivery. It involves determining the likelihood and potential impact of adverse events or hazards, such as infectious diseases, medication errors, or medical devices failures, and implementing measures to mitigate or manage those risks. The goal of risk assessment is to promote safe and high-quality care by identifying areas for improvement and taking action to minimize harm.

Unstable angina is a term used in cardiology to describe chest pain or discomfort that occurs suddenly and unexpectedly, often at rest or with minimal physical exertion. It is caused by an insufficient supply of oxygen-rich blood to the heart muscle due to reduced blood flow, typically as a result of partial or complete blockage of the coronary arteries.

Unlike stable angina, which tends to occur predictably during physical activity and can be relieved with rest or nitroglycerin, unstable angina is more severe, unpredictable, and may not respond to traditional treatments. It is considered a medical emergency because it can be a sign of an impending heart attack or other serious cardiac event.

Unstable angina is often treated in the hospital with medications such as nitroglycerin, beta blockers, calcium channel blockers, and antiplatelet agents to improve blood flow to the heart and prevent further complications. In some cases, more invasive treatments such as coronary angioplasty or bypass surgery may be necessary to restore blood flow to the affected areas of the heart.

Myocardial revascularization is a medical term that refers to the restoration of blood flow to the heart muscle (myocardium), typically through a surgical or interventional procedure. This is often performed in patients with coronary artery disease, where the buildup of plaque in the coronary arteries restricts blood flow to the heart muscle, causing symptoms such as chest pain (angina) or shortness of breath, and increasing the risk of a heart attack (myocardial infarction).

There are two main types of myocardial revascularization:

1. Coronary artery bypass grafting (CABG): This is a surgical procedure in which a healthy blood vessel from another part of the body is used to create a detour around the blocked or narrowed coronary artery, allowing blood to flow more freely to the heart muscle.
2. Percutaneous coronary intervention (PCI), also known as angioplasty and stenting: This is a minimally invasive procedure in which a thin catheter is inserted into an artery in the groin or arm and threaded up to the blocked or narrowed coronary artery. A balloon is then inflated to widen the artery, and a stent may be placed to keep it open.

Both procedures aim to improve symptoms, reduce the risk of heart attack, and prolong survival in appropriately selected patients with coronary artery disease.

The tricuspid valve is the heart valve that separates the right atrium and the right ventricle in the human heart. It is called "tricuspid" because it has three leaflets or cusps, which are also referred to as flaps or segments. These cusps are named anterior, posterior, and septal. The tricuspid valve's function is to prevent the backflow of blood from the ventricle into the atrium during systole, ensuring unidirectional flow of blood through the heart.

A biological marker, often referred to as a biomarker, is a measurable indicator that reflects the presence or severity of a disease state, or a response to a therapeutic intervention. Biomarkers can be found in various materials such as blood, tissues, or bodily fluids, and they can take many forms, including molecular, histologic, radiographic, or physiological measurements.

In the context of medical research and clinical practice, biomarkers are used for a variety of purposes, such as:

1. Diagnosis: Biomarkers can help diagnose a disease by indicating the presence or absence of a particular condition. For example, prostate-specific antigen (PSA) is a biomarker used to detect prostate cancer.
2. Monitoring: Biomarkers can be used to monitor the progression or regression of a disease over time. For instance, hemoglobin A1c (HbA1c) levels are monitored in diabetes patients to assess long-term blood glucose control.
3. Predicting: Biomarkers can help predict the likelihood of developing a particular disease or the risk of a negative outcome. For example, the presence of certain genetic mutations can indicate an increased risk for breast cancer.
4. Response to treatment: Biomarkers can be used to evaluate the effectiveness of a specific treatment by measuring changes in the biomarker levels before and after the intervention. This is particularly useful in personalized medicine, where treatments are tailored to individual patients based on their unique biomarker profiles.

It's important to note that for a biomarker to be considered clinically valid and useful, it must undergo rigorous validation through well-designed studies, including demonstrating sensitivity, specificity, reproducibility, and clinical relevance.

The Superior Sagittal Sinus is a medical term that refers to a venous sinus (a channel for blood flow) located in the superior part (highest portion) of the sagittal suture, which is the line along the top of the skull where the two parietal bones join in the middle. It runs from front to back, starting at the frontal bone and ending at the occipital bone, and it receives blood from veins that drain the cerebral hemispheres (the right and left halves of the brain).

The Superior Sagittal Sinus is an important structure in the circulatory system of the brain as it plays a critical role in draining venous blood from the cranial cavity. It also contains valveless venous channels that allow for the flow of cerebrospinal fluid (CSF) between the intracranial and extracranial compartments.

It is worth noting that any damage to this structure, such as through trauma or infection, can lead to serious neurological complications, including increased intracranial pressure, seizures, and even death.

An aortic aneurysm is a medical condition characterized by the abnormal widening or bulging of the wall of the aorta, which is the largest artery in the body. The aorta carries oxygenated blood from the heart to the rest of the body. When the aortic wall weakens, it can stretch and balloon out, forming an aneurysm.

Aortic aneurysms can occur anywhere along the aorta but are most commonly found in the abdominal section (abdominal aortic aneurysm) or the chest area (thoracic aortic aneurysm). The size and location of the aneurysm, as well as the patient's overall health, determine the risk of rupture and associated complications.

Aneurysms often do not cause symptoms until they become large or rupture. Symptoms may include:

* Pain in the chest, back, or abdomen
* Pulsating sensation in the abdomen
* Difficulty breathing
* Hoarseness
* Coughing or vomiting

Risk factors for aortic aneurysms include age, smoking, high blood pressure, family history, and certain genetic conditions. Treatment options depend on the size and location of the aneurysm and may include monitoring, medication, or surgical repair.

Cardioplegic solutions are specially formulated liquids used in medical procedures to induce cardiac arrest and protect the heart muscle during open-heart surgery. These solutions typically contain a combination of electrolytes, such as potassium and magnesium, which stop the heart from beating by interrupting its electrical activity. They may also include energy substrates, buffers, and other components to maintain the health and function of the heart cells during the period of arrest. The specific formulation of cardioplegic solutions can vary depending on the needs of the patient and the preferences of the medical team.

Myocardial contraction refers to the rhythmic and forceful shortening of heart muscle cells (myocytes) in the myocardium, which is the muscular wall of the heart. This process is initiated by electrical signals generated by the sinoatrial node, causing a wave of depolarization that spreads throughout the heart.

During myocardial contraction, calcium ions flow into the myocytes, triggering the interaction between actin and myosin filaments, which are the contractile proteins in the muscle cells. This interaction causes the myofilaments to slide past each other, resulting in the shortening of the sarcomeres (the functional units of muscle contraction) and ultimately leading to the contraction of the heart muscle.

Myocardial contraction is essential for pumping blood throughout the body and maintaining adequate circulation to vital organs. Any impairment in myocardial contractility can lead to various cardiac disorders, such as heart failure, cardiomyopathy, and arrhythmias.

Cardiac arrhythmias are abnormal heart rhythms that result from disturbances in the electrical conduction system of the heart. The heart's normal rhythm is controlled by an electrical signal that originates in the sinoatrial (SA) node, located in the right atrium. This signal travels through the atrioventricular (AV) node and into the ventricles, causing them to contract and pump blood throughout the body.

An arrhythmia occurs when there is a disruption in this electrical pathway or when the heart's natural pacemaker produces an abnormal rhythm. This can cause the heart to beat too fast (tachycardia), too slow (bradycardia), or irregularly.

There are several types of cardiac arrhythmias, including:

1. Atrial fibrillation: A rapid and irregular heartbeat that starts in the atria (the upper chambers of the heart).
2. Atrial flutter: A rapid but regular heartbeat that starts in the atria.
3. Supraventricular tachycardia (SVT): A rapid heartbeat that starts above the ventricles, usually in the atria or AV node.
4. Ventricular tachycardia: A rapid and potentially life-threatening heart rhythm that originates in the ventricles.
5. Ventricular fibrillation: A chaotic and disorganized electrical activity in the ventricles, which can be fatal if not treated immediately.
6. Heart block: A delay or interruption in the conduction of electrical signals from the atria to the ventricles.

Cardiac arrhythmias can cause various symptoms, such as palpitations, dizziness, shortness of breath, chest pain, and fatigue. In some cases, they may not cause any symptoms and go unnoticed. However, if left untreated, certain types of arrhythmias can lead to serious complications, including stroke, heart failure, or even sudden cardiac death.

Treatment for cardiac arrhythmias depends on the type, severity, and underlying causes. Options may include lifestyle changes, medications, cardioversion (electrical shock therapy), catheter ablation, implantable devices such as pacemakers or defibrillators, and surgery. It is essential to consult a healthcare professional for proper evaluation and management of cardiac arrhythmias.

Perfusion, in medical terms, refers to the process of circulating blood through the body's organs and tissues to deliver oxygen and nutrients and remove waste products. It is a measure of the delivery of adequate blood flow to specific areas or tissues in the body. Perfusion can be assessed using various methods, including imaging techniques like computed tomography (CT) scans, magnetic resonance imaging (MRI), and perfusion scintigraphy.

Perfusion is critical for maintaining proper organ function and overall health. When perfusion is impaired or inadequate, it can lead to tissue hypoxia, acidosis, and cell death, which can result in organ dysfunction or failure. Conditions that can affect perfusion include cardiovascular disease, shock, trauma, and certain surgical procedures.

Stroke volume is a term used in cardiovascular physiology and medicine. It refers to the amount of blood that is pumped out of the left ventricle of the heart during each contraction (systole). Specifically, it is the difference between the volume of blood in the left ventricle at the end of diastole (when the ventricle is filled with blood) and the volume at the end of systole (when the ventricle has contracted and ejected its contents into the aorta).

Stroke volume is an important measure of heart function, as it reflects the ability of the heart to pump blood effectively to the rest of the body. A low stroke volume may indicate that the heart is not pumping efficiently, while a high stroke volume may suggest that the heart is working too hard. Stroke volume can be affected by various factors, including heart disease, high blood pressure, and physical fitness level.

The formula for calculating stroke volume is:

Stroke Volume = End-Diastolic Volume - End-Systolic Volume

Where end-diastolic volume (EDV) is the volume of blood in the left ventricle at the end of diastole, and end-systolic volume (ESV) is the volume of blood in the left ventricle at the end of systole.

Nitroglycerin, also known as glyceryl trinitrate, is a medication used primarily for the treatment of angina pectoris (chest pain due to coronary artery disease) and hypertensive emergencies (severe high blood pressure). It belongs to a class of drugs called nitrates or organic nitrites.

Nitroglycerin works by relaxing and dilating the smooth muscle in blood vessels, which leads to decreased workload on the heart and increased oxygen delivery to the myocardium (heart muscle). This results in reduced symptoms of angina and improved cardiac function during hypertensive emergencies.

The drug is available in various forms, including sublingual tablets, sprays, transdermal patches, ointments, and intravenous solutions. The choice of formulation depends on the specific clinical situation and patient needs. Common side effects of nitroglycerin include headache, dizziness, and hypotension (low blood pressure).

The endocardium is the innermost layer of tissue that lines the chambers of the heart and the valves between them. It is a thin, smooth membrane that is in contact with the blood within the heart. This layer helps to maintain the heart's internal environment, facilitates the smooth movement of blood through the heart, and provides a protective barrier against infection and other harmful substances. The endocardium is composed of simple squamous epithelial cells called endothelial cells, which are supported by a thin layer of connective tissue.

Multidetector computed tomography (MDCT) is a type of computed tomography (CT) scan that uses multiple rows of detectors to acquire several slices of images simultaneously, thereby reducing the total time required for the scan and improving the spatial resolution. This technology allows for faster scanning of moving organs, such as the heart, and provides high-resolution images with detailed information about various body structures, including bones, soft tissues, and blood vessels. MDCT has numerous applications in diagnostic imaging, interventional procedures, and cancer staging and treatment follow-up.

The femoral vein is the large vein that runs through the thigh and carries oxygen-depleted blood from the lower limbs back to the heart. It is located in the femoral triangle, along with the femoral artery and nerve. The femoral vein begins at the knee as the popliteal vein, which then joins with the deep vein of the thigh to form the femoral vein. As it moves up the leg, it is joined by several other veins, including the great saphenous vein, before it becomes the external iliac vein at the inguinal ligament in the groin.

Angina pectoris is a medical term that describes chest pain or discomfort caused by an inadequate supply of oxygen-rich blood to the heart muscle. This condition often occurs due to coronary artery disease, where the coronary arteries become narrowed or blocked by the buildup of cholesterol, fatty deposits, and other substances, known as plaques. These blockages can reduce blood flow to the heart, causing ischemia (lack of oxygen) and leading to angina symptoms.

There are two primary types of angina: stable and unstable. Stable angina is predictable and usually occurs during physical exertion or emotional stress when the heart needs more oxygen-rich blood. The pain typically subsides with rest or after taking prescribed nitroglycerin medication, which helps widen the blood vessels and improve blood flow to the heart.

Unstable angina, on the other hand, is more severe and unpredictable. It can occur at rest, during sleep, or with minimal physical activity and may not be relieved by rest or nitroglycerin. Unstable angina is considered a medical emergency, as it could indicate an imminent heart attack.

Symptoms of angina pectoris include chest pain, pressure, tightness, or heaviness that typically radiates to the left arm, neck, jaw, or back. Shortness of breath, nausea, sweating, and fatigue may also accompany angina symptoms. Immediate medical attention is necessary if you experience chest pain or discomfort, especially if it's new, severe, or persistent, as it could be a sign of a more serious condition like a heart attack.

Cardiovascular models are simplified representations or simulations of the human cardiovascular system used in medical research, education, and training. These models can be physical, computational, or mathematical and are designed to replicate various aspects of the heart, blood vessels, and blood flow. They can help researchers study the structure and function of the cardiovascular system, test new treatments and interventions, and train healthcare professionals in diagnostic and therapeutic techniques.

Physical cardiovascular models may include artificial hearts, blood vessels, or circulation systems made from materials such as plastic, rubber, or silicone. These models can be used to study the mechanics of heart valves, the effects of different surgical procedures, or the impact of various medical devices on blood flow.

Computational and mathematical cardiovascular models use algorithms and equations to simulate the behavior of the cardiovascular system. These models may range from simple representations of a single heart chamber to complex simulations of the entire circulatory system. They can be used to study the electrical activity of the heart, the biomechanics of blood flow, or the distribution of drugs in the body.

Overall, cardiovascular models play an essential role in advancing our understanding of the human body and improving patient care.

A heart septal defect is a type of congenital heart defect, which means it is present at birth. It involves an abnormal opening in the septum, the wall that separates the two sides of the heart. This opening allows oxygen-rich blood to leak into the oxygen-poor blood chambers in the heart.

There are several types of heart septal defects, including:

1. Atrial Septal Defect (ASD): A hole in the atrial septum, the wall between the two upper chambers of the heart (the right and left atria).
2. Ventricular Septal Defect (VSD): A hole in the ventricular septum, the wall between the two lower chambers of the heart (the right and left ventricles).
3. Atrioventricular Septal Defect (AVSD): A combination of an ASD and a VSD, often accompanied by malformation of the mitral and/or tricuspid valves.

The severity of a heart septal defect depends on the size of the opening and its location in the septum. Small defects may cause no symptoms and may close on their own over time. Larger defects can lead to complications, such as heart failure, pulmonary hypertension, or infective endocarditis, and may require medical or surgical intervention.

Sensitivity and specificity are statistical measures used to describe the performance of a diagnostic test or screening tool in identifying true positive and true negative results.

* Sensitivity refers to the proportion of people who have a particular condition (true positives) who are correctly identified by the test. It is also known as the "true positive rate" or "recall." A highly sensitive test will identify most or all of the people with the condition, but may also produce more false positives.
* Specificity refers to the proportion of people who do not have a particular condition (true negatives) who are correctly identified by the test. It is also known as the "true negative rate." A highly specific test will identify most or all of the people without the condition, but may also produce more false negatives.

In medical testing, both sensitivity and specificity are important considerations when evaluating a diagnostic test. High sensitivity is desirable for screening tests that aim to identify as many cases of a condition as possible, while high specificity is desirable for confirmatory tests that aim to rule out the condition in people who do not have it.

It's worth noting that sensitivity and specificity are often influenced by factors such as the prevalence of the condition in the population being tested, the threshold used to define a positive result, and the reliability and validity of the test itself. Therefore, it's important to consider these factors when interpreting the results of a diagnostic test.

The endothelium is a thin layer of simple squamous epithelial cells that lines the interior surface of blood vessels, lymphatic vessels, and heart chambers. The vascular endothelium, specifically, refers to the endothelial cells that line the blood vessels. These cells play a crucial role in maintaining vascular homeostasis by regulating vasomotor tone, coagulation, platelet activation, inflammation, and permeability of the vessel wall. They also contribute to the growth and repair of the vascular system and are involved in various pathological processes such as atherosclerosis, hypertension, and diabetes.

Platelet aggregation inhibitors are a class of medications that prevent platelets (small blood cells involved in clotting) from sticking together and forming a clot. These drugs work by interfering with the ability of platelets to adhere to each other and to the damaged vessel wall, thereby reducing the risk of thrombosis (blood clot formation).

Platelet aggregation inhibitors are often prescribed for people who have an increased risk of developing blood clots due to various medical conditions such as atrial fibrillation, coronary artery disease, peripheral artery disease, stroke, or a history of heart attack. They may also be used in patients undergoing certain medical procedures, such as angioplasty and stenting, to prevent blood clot formation in the stents.

Examples of platelet aggregation inhibitors include:

1. Aspirin: A nonsteroidal anti-inflammatory drug (NSAID) that irreversibly inhibits the enzyme cyclooxygenase, which is involved in platelet activation and aggregation.
2. Clopidogrel (Plavix): A P2Y12 receptor antagonist that selectively blocks ADP-induced platelet activation and aggregation.
3. Prasugrel (Effient): A third-generation thienopyridine P2Y12 receptor antagonist, similar to clopidogrel but with faster onset and greater potency.
4. Ticagrelor (Brilinta): A direct-acting P2Y12 receptor antagonist that does not require metabolic activation and has a reversible binding profile.
5. Dipyridamole (Persantine): An antiplatelet agent that inhibits platelet aggregation by increasing cyclic adenosine monophosphate (cAMP) levels in platelets, which leads to decreased platelet reactivity.
6. Iloprost (Ventavis): A prostacyclin analogue that inhibits platelet aggregation and causes vasodilation, often used in the treatment of pulmonary arterial hypertension.
7. Cilostazol (Pletal): A phosphodiesterase III inhibitor that increases cAMP levels in platelets, leading to decreased platelet activation and aggregation, as well as vasodilation.
8. Ticlopidine (Ticlid): An older P2Y12 receptor antagonist with a slower onset of action and more frequent side effects compared to clopidogrel or prasugrel.

Congenital heart defects (CHDs) are structural abnormalities in the heart that are present at birth. They can affect any part of the heart's structure, including the walls of the heart, the valves inside the heart, and the major blood vessels that lead to and from the heart.

Congenital heart defects can range from mild to severe and can cause various symptoms depending on the type and severity of the defect. Some common symptoms of CHDs include cyanosis (a bluish tint to the skin, lips, and fingernails), shortness of breath, fatigue, poor feeding, and slow growth in infants and children.

There are many different types of congenital heart defects, including:

1. Septal defects: These are holes in the walls that separate the four chambers of the heart. The two most common septal defects are atrial septal defect (ASD) and ventricular septal defect (VSD).
2. Valve abnormalities: These include narrowed or leaky valves, which can affect blood flow through the heart.
3. Obstruction defects: These occur when blood flow is blocked or restricted due to narrowing or absence of a part of the heart's structure. Examples include pulmonary stenosis and coarctation of the aorta.
4. Cyanotic heart defects: These cause a lack of oxygen in the blood, leading to cyanosis. Examples include tetralogy of Fallot and transposition of the great arteries.

The causes of congenital heart defects are not fully understood, but genetic factors and environmental influences during pregnancy may play a role. Some CHDs can be detected before birth through prenatal testing, while others may not be diagnosed until after birth or later in childhood. Treatment for CHDs may include medication, surgery, or other interventions to improve blood flow and oxygenation of the body's tissues.

Lactates, also known as lactic acid, are compounds that are produced by muscles during intense exercise or other conditions of low oxygen supply. They are formed from the breakdown of glucose in the absence of adequate oxygen to complete the full process of cellular respiration. This results in the production of lactate and a hydrogen ion, which can lead to a decrease in pH and muscle fatigue.

In a medical context, lactates may be measured in the blood as an indicator of tissue oxygenation and metabolic status. Elevated levels of lactate in the blood, known as lactic acidosis, can indicate poor tissue perfusion or hypoxia, and may be seen in conditions such as sepsis, cardiac arrest, and severe shock. It is important to note that lactates are not the primary cause of acidemia (low pH) in lactic acidosis, but rather a marker of the underlying process.

The pericardium is the double-walled sac that surrounds the heart. It has an outer fibrous layer and an inner serous layer, which further divides into two parts: the parietal layer lining the fibrous pericardium and the visceral layer (epicardium) closely adhering to the heart surface.

The space between these two layers is filled with a small amount of lubricating serous fluid, allowing for smooth movement of the heart within the pericardial cavity. The pericardium provides protection, support, and helps maintain the heart's normal position within the chest while reducing friction during heart contractions.

Myocardial perfusion imaging (MPI) is a non-invasive nuclear medicine test used to assess the blood flow to the heart muscle (myocardium). It typically involves the injection of a radioactive tracer, such as thallium-201 or technetium-99m sestamibi, into a vein. The tracer is taken up by healthy heart muscle in proportion to blood flow. A special camera then takes images of the distribution of the tracer within the heart, providing information about areas of reduced or blocked blood flow (ischemia) or scarred tissue (infarction). MPI can help diagnose coronary artery disease, assess the effectiveness of treatments, and determine prognosis.

Vascular malformations are abnormalities in the development and growth of blood vessels and lymphatic vessels that can occur anywhere in the body. They can be present at birth or develop later in life, and they can affect both the form and function of the affected tissues and organs. Vascular malformations can involve arteries, veins, capillaries, and/or lymphatic vessels, and they can range from simple, localized lesions to complex, multifocal disorders.

Vascular malformations are typically classified based on their location, size, flow characteristics, and the type of blood or lymphatic vessels involved. Some common types of vascular malformations include:

1. Capillary malformations (CMs): These are characterized by abnormal dilated capillaries that can cause red or pink discoloration of the skin, typically on the face or neck.
2. Venous malformations (VMs): These involve abnormal veins that can cause swelling, pain, and disfigurement in the affected area.
3. Lymphatic malformations (LMs): These involve abnormal lymphatic vessels that can cause swelling, infection, and other complications.
4. Arteriovenous malformations (AVMs): These involve a tangled mass of arteries and veins that can cause high-flow lesions, bleeding, and other serious complications.
5. Combined vascular malformations: These involve a combination of different types of blood or lymphatic vessels, such as capillary-lymphatic-venous malformations (CLVMs) or arteriovenous-lymphatic malformations (AVLMs).

The exact cause of vascular malformations is not fully understood, but they are believed to result from genetic mutations that affect the development and growth of blood vessels and lymphatic vessels. Treatment options for vascular malformations depend on the type, size, location, and severity of the lesion, as well as the patient's age and overall health. Treatment may include medication, compression garments, sclerotherapy, surgery, or a combination of these approaches.

Atrial septal defect (ASD) is a type of congenital heart defect that involves the septum, which is the wall that separates the two upper chambers of the heart (atria). An ASD is a hole or abnormal opening in the atrial septum, allowing oxygen-rich blood to leak into the oxygen-poor blood chambers in the heart. This leads to an overload of blood in the right side of the heart, which can cause enlargement of the heart and increased work for the right ventricle.

ASDs can vary in size, and small defects may not cause any symptoms or require treatment. Larger defects, however, can result in symptoms such as shortness of breath, fatigue, and heart rhythm abnormalities. Over time, if left untreated, ASDs can lead to complications like pulmonary hypertension, atrial fibrillation, and stroke.

Treatment for ASD typically involves surgical closure of the defect or catheter-based procedures using devices to close the hole. The choice of treatment depends on factors such as the size and location of the defect, the patient's age and overall health, and the presence of any coexisting conditions.

Echocardiography, Doppler, color is a type of ultrasound test that uses sound waves to create detailed moving images of the heart and its blood vessels. In this technique, color Doppler is used to visualize the direction and speed of blood flow through the heart and great vessels. The movement of the red blood cells causes a change in frequency of the reflected sound waves (Doppler shift), which can be used to calculate the velocity and direction of the blood flow. By adding color to the Doppler image, it becomes easier for the interpreting physician to understand the complex three-dimensional motion of blood through the heart. This test is often used to diagnose and monitor various heart conditions, including valve disorders, congenital heart defects, and cardiac muscle diseases.

Mitral valve insufficiency, also known as mitral regurgitation, is a cardiac condition in which the mitral valve located between the left atrium and left ventricle of the heart does not close properly, causing blood to flow backward into the atrium during contraction of the ventricle. This leads to an increased volume load on the left heart chamber and can result in symptoms such as shortness of breath, fatigue, and fluid retention. The condition can be caused by various factors including valve damage due to degenerative changes, infective endocarditis, rheumatic heart disease, or trauma. Treatment options include medication, mitral valve repair, or replacement surgery depending on the severity and underlying cause of the insufficiency.

Doppler echocardiography is a type of ultrasound test that uses high-frequency sound waves to produce detailed images of the heart and its blood vessels. It measures the direction and speed of blood flow in the heart and major blood vessels leading to and from the heart. This helps to evaluate various conditions such as valve problems, congenital heart defects, and heart muscle diseases.

In Doppler echocardiography, a small handheld device called a transducer is placed on the chest, which emits sound waves that bounce off the heart and blood vessels. The transducer then picks up the returning echoes, which are processed by a computer to create moving images of the heart.

The Doppler effect is used to measure the speed and direction of blood flow. This occurs when the frequency of the sound waves changes as they bounce off moving objects, such as red blood cells. By analyzing these changes, the ultrasound machine can calculate the velocity and direction of blood flow in different parts of the heart.

Doppler echocardiography is a non-invasive test that does not require any needles or dyes. It is generally safe and painless, although patients may experience some discomfort from the pressure applied by the transducer on the chest. The test usually takes about 30 to 60 minutes to complete.

The Stellate Ganglion is a part of the sympathetic nervous system. It's a collection of nerve cells (a ganglion) located in the neck, more specifically at the level of the sixth and seventh cervical vertebrae. The stellate ganglion is formed by the fusion of the inferior cervical ganglion and the first thoracic ganglion.

This ganglion plays a crucial role in the body's "fight or flight" response, providing sympathetic innervation to the head, neck, upper extremities, and heart. It's responsible for various functions including regulation of blood flow, sweat gland activity, and contributing to the sensory innervation of the head and neck.

Stellate ganglion block is a medical procedure used to diagnose or treat certain conditions like pain disorders, by injecting local anesthetic near the stellate ganglion to numb the area and interrupt nerve signals.

Dilated cardiomyopathy (DCM) is a type of cardiomyopathy characterized by the enlargement and weakened contraction of the heart's main pumping chamber (the left ventricle). This enlargement and weakness can lead to symptoms such as shortness of breath, fatigue, and fluid retention. DCM can be caused by various factors including genetics, viral infections, alcohol and drug abuse, and other medical conditions like high blood pressure and diabetes. It is important to note that this condition can lead to heart failure if left untreated.

A diverticulum is a small sac or pouch that forms as a result of a weakness in the wall of a hollow organ, such as the intestine. These sacs can become inflamed or infected, leading to conditions like diverticulitis. Diverticula are common in the large intestine, particularly in the colon, and are more likely to develop with age. They are usually asymptomatic but can cause symptoms such as abdominal pain, bloating, constipation, or diarrhea if they become inflamed or infected.

An arterio-arterial fistula is an abnormal connection or passage between two arteries. Arteries are blood vessels that carry oxygen-rich blood from the heart to the rest of the body. Under normal circumstances, arteries do not directly communicate with each other; instead, they supply blood to capillaries, which then deliver the blood to veins.

An arterio-arterial fistula can result from various causes, including congenital defects, trauma, or as a complication of medical procedures such as arterial catheterization or surgical interventions. The presence of an arterio-arterial fistula may lead to several hemodynamic consequences, depending on the size, location, and chronicity of the communication. These can include altered blood flow patterns, increased pressure in the affected arteries, and potential cardiac complications due to volume overload.

Symptoms of an arterio-arterial fistula may vary widely, from being asymptomatic to experiencing palpitations, shortness of breath, fatigue, or even congestive heart failure in severe cases. The diagnosis typically involves imaging studies such as ultrasound, CT angiography, or MRI angiography to visualize the abnormal communication and assess its hemodynamic impact. Treatment options may include observation, endovascular interventions, or surgical repair, depending on the individual case.

Contrast media are substances that are administered to a patient in order to improve the visibility of internal body structures or processes in medical imaging techniques such as X-rays, CT scans, MRI scans, and ultrasounds. These media can be introduced into the body through various routes, including oral, rectal, or intravenous administration.

Contrast media work by altering the appearance of bodily structures in imaging studies. For example, when a patient undergoes an X-ray examination, contrast media can be used to highlight specific organs, tissues, or blood vessels, making them more visible on the resulting images. In CT and MRI scans, contrast media can help to enhance the differences between normal and abnormal tissues, allowing for more accurate diagnosis and treatment planning.

There are several types of contrast media available, each with its own specific properties and uses. Some common examples include barium sulfate, which is used as a contrast medium in X-ray studies of the gastrointestinal tract, and iodinated contrast media, which are commonly used in CT scans to highlight blood vessels and other structures.

While contrast media are generally considered safe, they can sometimes cause adverse reactions, ranging from mild symptoms such as nausea or hives to more serious complications such as anaphylaxis or kidney damage. As a result, it is important for healthcare providers to carefully evaluate each patient's medical history and individual risk factors before administering contrast media.

Chest pain is a discomfort or pain that you feel in the chest area. The pain can be sharp, dull, burning, crushing, heaviness, or tightness. It may be accompanied by other symptoms such as shortness of breath, sweating, nausea, dizziness, or pain that radiates to the arm, neck, jaw, or back.

Chest pain can have many possible causes, including heart-related conditions such as angina or a heart attack, lung conditions such as pneumonia or pleurisy, gastrointestinal problems such as acid reflux or gastritis, musculoskeletal issues such as costochondritis or muscle strain, and anxiety or panic attacks.

It is important to seek immediate medical attention if you experience chest pain that is severe, persistent, or accompanied by other concerning symptoms, as it may be a sign of a serious medical condition. A healthcare professional can evaluate your symptoms, perform tests, and provide appropriate treatment.

Diastole is the phase of the cardiac cycle during which the heart muscle relaxes and the chambers of the heart fill with blood. It follows systole, the phase in which the heart muscle contracts and pumps blood out to the body. In a normal resting adult, diastole lasts for approximately 0.4-0.5 seconds during each heartbeat. The period of diastole is divided into two phases: early diastole and late diastole. During early diastole, the ventricles fill with blood due to the pressure difference between the atria and ventricles. During late diastole, the atrioventricular valves close, and the ventricles continue to fill with blood due to the relaxation of the ventricular muscle and the compliance of the ventricular walls. The duration and pressure changes during diastole are important for maintaining adequate cardiac output and blood flow to the body.

Cardiovascular surgical procedures refer to a range of surgeries performed on the heart and blood vessels to treat or manage various cardiovascular conditions. These surgeries can be open or minimally invasive, and they aim to correct structural abnormalities, improve blood flow, or replace damaged or diseased parts of the cardiovascular system.

Some common types of cardiovascular surgical procedures include:

1. Coronary artery bypass grafting (CABG): This surgery involves taking a healthy blood vessel from another part of the body and using it to create a detour around a blocked or narrowed coronary artery, improving blood flow to the heart muscle.
2. Heart valve repair or replacement: When one or more heart valves become damaged or diseased, they may not open or close properly, leading to reduced blood flow or leakage of blood backward through the valve. In these cases, surgeons may repair or replace the affected valve with a mechanical or biological prosthetic valve.
3. Aneurysm repair: An aneurysm is a weakened area in the wall of an artery that can bulge and potentially rupture, causing severe bleeding. Surgeons can repair an aneurysm by reinforcing the weakened area with a graft or by replacing the affected section of the blood vessel.
4. Heart transplant: In cases where heart failure is irreversible and all other treatment options have been exhausted, a heart transplant may be necessary. This procedure involves removing the damaged heart and replacing it with a healthy donor heart.
5. Ventricular assist devices (VADs): These are mechanical pumps that can be implanted to help support heart function in patients with advanced heart failure who are not candidates for heart transplants. VADs can help improve blood flow, reduce symptoms, and increase the patient's quality of life.
6. Minimally invasive procedures: Advances in technology have led to the development of several minimally invasive cardiovascular surgical procedures, such as robotic-assisted heart surgery, video-assisted thoracoscopic surgery (VATS), and transcatheter aortic valve replacement (TAVR). These techniques typically involve smaller incisions, reduced blood loss, shorter hospital stays, and faster recovery times compared to traditional open-heart surgeries.

"Device Removal" in a medical context generally refers to the surgical or nonsurgical removal of a medical device that has been previously implanted in a patient's body. The purpose of removing the device may vary, depending on the individual case. Some common reasons for device removal include infection, malfunction, rejection, or when the device is no longer needed.

Examples of medical devices that may require removal include pacemakers, implantable cardioverter-defibrillators (ICDs), artificial joints, orthopedic hardware, breast implants, cochlear implants, and intrauterine devices (IUDs). The procedure for device removal will depend on the type of device, its location in the body, and the reason for its removal.

It is important to note that device removal carries certain risks, such as bleeding, infection, damage to surrounding tissues, or complications related to anesthesia. Therefore, the decision to remove a medical device should be made carefully, considering both the potential benefits and risks of the procedure.

Regional blood flow (RBF) refers to the rate at which blood flows through a specific region or organ in the body, typically expressed in milliliters per minute per 100 grams of tissue (ml/min/100g). It is an essential physiological parameter that reflects the delivery of oxygen and nutrients to tissues while removing waste products. RBF can be affected by various factors such as metabolic demands, neural regulation, hormonal influences, and changes in blood pressure or vascular resistance. Measuring RBF is crucial for understanding organ function, diagnosing diseases, and evaluating the effectiveness of treatments.

Myocardial reperfusion injury is a pathological process that occurs when blood flow is restored to the heart muscle (myocardium) after a period of ischemia or reduced oxygen supply, such as during a myocardial infarction (heart attack). The restoration of blood flow, although necessary to salvage the dying tissue, can itself cause further damage to the heart muscle. This paradoxical phenomenon is known as myocardial reperfusion injury.

The mechanisms behind myocardial reperfusion injury are complex and involve several processes, including:

1. Oxidative stress: The sudden influx of oxygen into the previously ischemic tissue leads to an overproduction of reactive oxygen species (ROS), which can damage cellular structures, such as proteins, lipids, and DNA.
2. Calcium overload: During reperfusion, there is an increase in calcium influx into the cardiomyocytes (heart muscle cells). This elevated intracellular calcium level can disrupt normal cellular functions, leading to further damage.
3. Inflammation: Reperfusion triggers an immune response, with the recruitment of inflammatory cells, such as neutrophils and monocytes, to the site of injury. These cells release cytokines and other mediators that can exacerbate tissue damage.
4. Mitochondrial dysfunction: The restoration of blood flow can cause mitochondria, the powerhouses of the cell, to malfunction, leading to the release of pro-apoptotic factors and contributing to cell death.
5. Vasoconstriction and microvascular obstruction: During reperfusion, there may be vasoconstriction of the small blood vessels (microvasculature) in the heart, which can further limit blood flow and contribute to tissue damage.

Myocardial reperfusion injury is a significant concern because it can negate some of the benefits of early reperfusion therapy, such as thrombolysis or primary percutaneous coronary intervention (PCI), used to treat acute myocardial infarction. Strategies to minimize myocardial reperfusion injury are an area of active research and include pharmacological interventions, ischemic preconditioning, and remote ischemic conditioning.

Heart disease is a broad term for a class of diseases that involve the heart or blood vessels. It's often used to refer to conditions that include:

1. Coronary artery disease (CAD): This is the most common type of heart disease. It occurs when the arteries that supply blood to the heart become hardened and narrowed due to the buildup of cholesterol and other substances, which can lead to chest pain (angina), shortness of breath, or a heart attack.

2. Heart failure: This condition occurs when the heart is unable to pump blood efficiently to meet the body's needs. It can be caused by various conditions, including coronary artery disease, high blood pressure, and cardiomyopathy.

3. Arrhythmias: These are abnormal heart rhythms, which can be too fast, too slow, or irregular. They can lead to symptoms such as palpitations, dizziness, and fainting.

4. Valvular heart disease: This involves damage to one or more of the heart's four valves, which control blood flow through the heart. Damage can be caused by various conditions, including infection, rheumatic fever, and aging.

5. Cardiomyopathy: This is a disease of the heart muscle that makes it harder for the heart to pump blood efficiently. It can be caused by various factors, including genetics, viral infections, and drug abuse.

6. Pericardial disease: This involves inflammation or other problems with the sac surrounding the heart (pericardium). It can cause chest pain and other symptoms.

7. Congenital heart defects: These are heart conditions that are present at birth, such as a hole in the heart or abnormal blood vessels. They can range from mild to severe and may require medical intervention.

8. Heart infections: The heart can become infected by bacteria, viruses, or parasites, leading to various symptoms and complications.

It's important to note that many factors can contribute to the development of heart disease, including genetics, lifestyle choices, and certain medical conditions. Regular check-ups and a healthy lifestyle can help reduce the risk of developing heart disease.

The Chi-square distribution is a continuous probability distribution that is often used in statistical hypothesis testing. It is the distribution of a sum of squares of k independent standard normal random variables. The resulting quantity follows a chi-square distribution with k degrees of freedom, denoted as χ²(k).

The probability density function (pdf) of the Chi-square distribution with k degrees of freedom is given by:

f(x; k) = (1/ (2^(k/2) * Γ(k/2))) \* x^((k/2)-1) \* e^(-x/2), for x > 0 and 0, otherwise.

Where Γ(k/2) is the gamma function evaluated at k/2. The mean and variance of a Chi-square distribution with k degrees of freedom are k and 2k, respectively.

The Chi-square distribution has various applications in statistical inference, including testing goodness-of-fit, homogeneity of variances, and independence in contingency tables.

Atrioventricular (AV) block is a disorder of the electrical conduction system of the heart that causes a delay or interruption in the transmission of electrical signals from the atria (the upper chambers of the heart) to the ventricles (the lower chambers of the heart). This results in an abnormal heart rhythm, also known as an arrhythmia.

There are three degrees of AV block:

1. First-degree AV block: In this type of AV block, there is a delay in the conduction of electrical signals from the atria to the ventricles, but all signals are eventually conducted. This condition may not cause any symptoms and is often discovered during a routine electrocardiogram (ECG).
2. Second-degree AV block: In this type of AV block, some electrical signals from the atria are not conducted to the ventricles. There are two types of second-degree AV block: Mobitz type I and Mobitz type II. Mobitz type I is characterized by a progressive prolongation of the PR interval (the time between the electrical activation of the atria and ventricles) until a QRS complex (which represents the electrical activation of the ventricles) is dropped. Mobitz type II is characterized by a constant PR interval with occasional non-conducted P waves.
3. Third-degree AV block: In this type of AV block, no electrical signals are conducted from the atria to the ventricles. The atria and ventricles beat independently of each other, resulting in a slow heart rate (bradycardia) and an irregular rhythm. This condition can be life-threatening if not treated promptly.

The causes of AV block include aging, heart disease, medications, and certain medical conditions such as hypothyroidism and Lyme disease. Treatment depends on the severity of the condition and may include medication, a pacemaker, or surgery.

Catheterization is a medical procedure in which a catheter (a flexible tube) is inserted into the body to treat various medical conditions or for diagnostic purposes. The specific definition can vary depending on the area of medicine and the particular procedure being discussed. Here are some common types of catheterization:

1. Urinary catheterization: This involves inserting a catheter through the urethra into the bladder to drain urine. It is often performed to manage urinary retention, monitor urine output in critically ill patients, or assist with surgical procedures.
2. Cardiac catheterization: A procedure where a catheter is inserted into a blood vessel, usually in the groin or arm, and guided to the heart. This allows for various diagnostic tests and treatments, such as measuring pressures within the heart chambers, assessing blood flow, or performing angioplasty and stenting of narrowed coronary arteries.
3. Central venous catheterization: A catheter is inserted into a large vein, typically in the neck, chest, or groin, to administer medications, fluids, or nutrition, or to monitor central venous pressure.
4. Peritoneal dialysis catheterization: A catheter is placed into the abdominal cavity for individuals undergoing peritoneal dialysis, a type of kidney replacement therapy.
5. Neurological catheterization: In some cases, a catheter may be inserted into the cerebrospinal fluid space (lumbar puncture) or the brain's ventricular system (ventriculostomy) to diagnose or treat various neurological conditions.

These are just a few examples of catheterization procedures in medicine. The specific definition and purpose will depend on the medical context and the particular organ or body system involved.

Propranolol is a medication that belongs to a class of drugs called beta blockers. Medically, it is defined as a non-selective beta blocker, which means it blocks the effects of both epinephrine (adrenaline) and norepinephrine (noradrenaline) on the heart and other organs. These effects include reducing heart rate, contractility, and conduction velocity, leading to decreased oxygen demand by the myocardium. Propranolol is used in the management of various conditions such as hypertension, angina pectoris, arrhythmias, essential tremor, anxiety disorders, and infants with congenital heart defects. It may also be used to prevent migraines and reduce the risk of future heart attacks. As with any medication, it should be taken under the supervision of a healthcare provider due to potential side effects and contraindications.

Dextrocardia is a medical condition in which the heart is positioned on the right side of the chest instead of the left side. This is a congenital condition, meaning it is present at birth. In people with dextrocardia, the heart's structure and function are usually normal, but the orientation of the heart within the chest is reversed.

There are two main types of dextrocardia:

1. Dextrocardia without visceral situs inversus: In this type, the heart is on the right side of the chest, but the other organs in the chest and abdomen are in their normal positions. This is a rare condition and can be associated with other congenital heart defects.
2. Dextrocardia with visceral situs inversus: In this type, the heart is on the right side of the chest, and the other organs in the chest and abdomen are mirrored or reversed from their normal positions. This is a less common form of dextrocardia and is often referred to as "situs inversus totalis."

It's important to note that while dextrocardia itself is not a life-threatening condition, people with this condition may have other heart defects or medical issues that require treatment. If you or someone you know has been diagnosed with dextrocardia, it's essential to consult with a healthcare professional for proper evaluation and management.

An exercise test, also known as a stress test or an exercise stress test, is a medical procedure used to evaluate the heart's function and response to physical exertion. It typically involves walking on a treadmill or pedaling a stationary bike while being monitored for changes in heart rate, blood pressure, electrocardiogram (ECG), and sometimes other variables such as oxygen consumption or gas exchange.

During the test, the patient's symptoms, such as chest pain or shortness of breath, are also closely monitored. The exercise test can help diagnose coronary artery disease, assess the severity of heart-related symptoms, and evaluate the effectiveness of treatments for heart conditions. It may also be used to determine a person's safe level of physical activity and fitness.

There are different types of exercise tests, including treadmill stress testing, stationary bike stress testing, nuclear stress testing, and stress echocardiography. The specific type of test used depends on the patient's medical history, symptoms, and overall health status.

Anti-arrhythmia agents are a class of medications used to treat abnormal heart rhythms or arrhythmias. These drugs work by modifying the electrical activity of the heart to restore and maintain a normal heart rhythm. There are several types of anti-arrhythmia agents, including:

1. Sodium channel blockers: These drugs slow down the conduction of electrical signals in the heart, which helps to reduce rapid or irregular heartbeats. Examples include flecainide, propafenone, and quinidine.
2. Beta-blockers: These medications work by blocking the effects of adrenaline on the heart, which helps to slow down the heart rate and reduce the force of heart contractions. Examples include metoprolol, atenolol, and esmolol.
3. Calcium channel blockers: These drugs block the entry of calcium into heart muscle cells, which helps to slow down the heart rate and reduce the force of heart contractions. Examples include verapamil and diltiazem.
4. Potassium channel blockers: These medications work by prolonging the duration of the heart's electrical cycle, which helps to prevent abnormal rhythms. Examples include amiodarone and sotalol.
5. Digoxin: This drug increases the force of heart contractions and slows down the heart rate, which can help to restore a normal rhythm in certain types of arrhythmias.

It's important to note that anti-arrhythmia agents can have significant side effects and should only be prescribed by a healthcare professional who has experience in managing arrhythmias. Close monitoring is necessary to ensure the medication is working effectively and not causing any adverse effects.

Postoperative complications refer to any unfavorable condition or event that occurs during the recovery period after a surgical procedure. These complications can vary in severity and may include, but are not limited to:

1. Infection: This can occur at the site of the incision or inside the body, such as pneumonia or urinary tract infection.
2. Bleeding: Excessive bleeding (hemorrhage) can lead to a drop in blood pressure and may require further surgical intervention.
3. Blood clots: These can form in the deep veins of the legs (deep vein thrombosis) and can potentially travel to the lungs (pulmonary embolism).
4. Wound dehiscence: This is when the surgical wound opens up, which can lead to infection and further complications.
5. Pulmonary issues: These include atelectasis (collapsed lung), pneumonia, or respiratory failure.
6. Cardiovascular problems: These include abnormal heart rhythms (arrhythmias), heart attack, or stroke.
7. Renal failure: This can occur due to various reasons such as dehydration, blood loss, or the use of certain medications.
8. Pain management issues: Inadequate pain control can lead to increased stress, anxiety, and decreased mobility.
9. Nausea and vomiting: These can be caused by anesthesia, opioid pain medication, or other factors.
10. Delirium: This is a state of confusion and disorientation that can occur in the elderly or those with certain medical conditions.

Prompt identification and management of these complications are crucial to ensure the best possible outcome for the patient.

Acetylcholine is a neurotransmitter, a type of chemical messenger that transmits signals across a chemical synapse from one neuron (nerve cell) to another "target" neuron, muscle cell, or gland cell. It is involved in both peripheral and central nervous system functions.

In the peripheral nervous system, acetylcholine acts as a neurotransmitter at the neuromuscular junction, where it transmits signals from motor neurons to activate muscles. Acetylcholine also acts as a neurotransmitter in the autonomic nervous system, where it is involved in both the sympathetic and parasympathetic systems.

In the central nervous system, acetylcholine plays a role in learning, memory, attention, and arousal. Disruptions in cholinergic neurotransmission have been implicated in several neurological disorders, including Alzheimer's disease, Parkinson's disease, and myasthenia gravis.

Acetylcholine is synthesized from choline and acetyl-CoA by the enzyme choline acetyltransferase and is stored in vesicles at the presynaptic terminal of the neuron. When a nerve impulse arrives, the vesicles fuse with the presynaptic membrane, releasing acetylcholine into the synapse. The acetylcholine then binds to receptors on the postsynaptic membrane, triggering a response in the target cell. Acetylcholine is subsequently degraded by the enzyme acetylcholinesterase, which terminates its action and allows for signal transduction to be repeated.

Cardiac electrophysiology is a branch of medicine that deals with the study and understanding of the electrical activities of the heart. It involves the diagnosis and treatment of various heart rhythm disorders (arrhythmias) such as bradycardia (slow heart rate), tachycardia (fast heart rate), atrial fibrillation, atrial flutter, ventricular fibrillation, and other rhythm abnormalities.

Cardiac electrophysiologists use various diagnostic tests, including electrocardiograms (ECGs), Holter monitors, event monitors, and invasive procedures such as electrophysiology studies (EPS) and catheter ablation to evaluate and treat heart rhythm disorders. The goal of treatment is to restore a normal heart rhythm and prevent complications associated with arrhythmias, such as stroke or heart failure.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.

As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.

In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.

Analysis of Variance (ANOVA) is a statistical technique used to compare the means of two or more groups and determine whether there are any significant differences between them. It is a way to analyze the variance in a dataset to determine whether the variability between groups is greater than the variability within groups, which can indicate that the groups are significantly different from one another.

ANOVA is based on the concept of partitioning the total variance in a dataset into two components: variance due to differences between group means (also known as "between-group variance") and variance due to differences within each group (also known as "within-group variance"). By comparing these two sources of variance, ANOVA can help researchers determine whether any observed differences between groups are statistically significant, or whether they could have occurred by chance.

ANOVA is a widely used technique in many areas of research, including biology, psychology, engineering, and business. It is often used to compare the means of two or more experimental groups, such as a treatment group and a control group, to determine whether the treatment had a significant effect. ANOVA can also be used to compare the means of different populations or subgroups within a population, to identify any differences that may exist between them.

Ventricular Tachycardia (VT) is a rapid heart rhythm that originates from the ventricles, the lower chambers of the heart. It is defined as three or more consecutive ventricular beats at a rate of 120 beats per minute or greater in a resting adult. This abnormal heart rhythm can cause the heart to pump less effectively, leading to inadequate blood flow to the body and potentially life-threatening conditions such as hypotension, shock, or cardiac arrest.

VT can be classified into three types based on its duration, hemodynamic stability, and response to treatment:

1. Non-sustained VT (NSVT): It lasts for less than 30 seconds and is usually well tolerated without causing significant symptoms or hemodynamic instability.
2. Sustained VT (SVT): It lasts for more than 30 seconds, causes symptoms such as palpitations, dizziness, shortness of breath, or chest pain, and may lead to hemodynamic instability.
3. Pulseless VT: It is a type of sustained VT that does not produce a pulse, blood pressure, or adequate cardiac output, requiring immediate electrical cardioversion or defibrillation to restore a normal heart rhythm.

VT can occur in people with various underlying heart conditions such as coronary artery disease, cardiomyopathy, valvular heart disease, congenital heart defects, and electrolyte imbalances. It can also be triggered by certain medications, substance abuse, or electrical abnormalities in the heart. Prompt diagnosis and treatment of VT are crucial to prevent complications and improve outcomes.

Balloon occlusion is a medical procedure that involves the use of a small, deflated balloon at the end of a catheter, which can be inserted into a blood vessel or other tubular structure in the body. Once the balloon is in position, it is inflated with a fluid or gas to create a blockage or obstruction in the vessel. This can be used for various medical purposes, such as:

1. Controlling bleeding: By inflating the balloon in a blood vessel, doctors can temporarily stop the flow of blood to a specific area, allowing them to treat injuries or abnormalities that are causing excessive bleeding.
2. Vessel narrowing or blockage assessment: Balloon occlusion can be used to assess the severity of narrowing or blockages in blood vessels. By inflating the balloon and measuring the pressure differences upstream and downstream, doctors can determine the extent of the obstruction and plan appropriate treatment.
3. Embolization therapy: In some cases, balloon occlusion is used to deliver embolic agents (such as coils, particles, or glue) that block off blood flow to specific areas. This can be useful in treating conditions like tumors, arteriovenous malformations, or aneurysms.
4. Temporary vessel occlusion during surgery: During certain surgical procedures, it may be necessary to temporarily stop the flow of blood to a specific area. Balloon occlusion can be used to achieve this quickly and safely.
5. Assisting in the placement of stents or other devices: Balloon occlusion can help position and deploy stents or other medical devices by providing temporary support or blocking off blood flow during the procedure.

It is important to note that balloon occlusion procedures carry potential risks, such as vessel injury, infection, or embolism (the blockage of a blood vessel by a clot or foreign material). These risks should be carefully weighed against the benefits when considering this type of treatment.

Lactic acid, also known as 2-hydroxypropanoic acid, is a chemical compound that plays a significant role in various biological processes. In the context of medicine and biochemistry, lactic acid is primarily discussed in relation to muscle metabolism and cellular energy production. Here's a medical definition for lactic acid:

Lactic acid (LA): A carboxylic acid with the molecular formula C3H6O3 that plays a crucial role in anaerobic respiration, particularly during strenuous exercise or conditions of reduced oxygen availability. It is formed through the conversion of pyruvate, catalyzed by the enzyme lactate dehydrogenase (LDH), when there is insufficient oxygen to complete the final step of cellular respiration in the Krebs cycle. The accumulation of lactic acid can lead to acidosis and muscle fatigue. Additionally, lactic acid serves as a vital intermediary in various metabolic pathways and is involved in the production of glucose through gluconeogenesis in the liver.

Right atrial function refers to the role and performance of the right atrium in the heart. The right atrium is one of the four chambers of the heart and is responsible for receiving deoxygenated blood from the body via the superior and inferior vena cava. It then contracts to help pump the blood into the right ventricle, which subsequently sends it to the lungs for oxygenation.

Right atrial function can be assessed through various methods, including echocardiography, cardiac magnetic resonance imaging (MRI), and electrocardiogram (ECG). Abnormalities in right atrial function may indicate underlying heart conditions such as right-sided heart failure, atrial fibrillation, or other cardiovascular diseases. Proper evaluation and monitoring of right atrial function are essential for effective diagnosis, treatment, and management of these conditions.

Reproducibility of results in a medical context refers to the ability to obtain consistent and comparable findings when a particular experiment or study is repeated, either by the same researcher or by different researchers, following the same experimental protocol. It is an essential principle in scientific research that helps to ensure the validity and reliability of research findings.

In medical research, reproducibility of results is crucial for establishing the effectiveness and safety of new treatments, interventions, or diagnostic tools. It involves conducting well-designed studies with adequate sample sizes, appropriate statistical analyses, and transparent reporting of methods and findings to allow other researchers to replicate the study and confirm or refute the results.

The lack of reproducibility in medical research has become a significant concern in recent years, as several high-profile studies have failed to produce consistent findings when replicated by other researchers. This has led to increased scrutiny of research practices and a call for greater transparency, rigor, and standardization in the conduct and reporting of medical research.

A case-control study is an observational research design used to identify risk factors or causes of a disease or health outcome. In this type of study, individuals with the disease or condition (cases) are compared with similar individuals who do not have the disease or condition (controls). The exposure history or other characteristics of interest are then compared between the two groups to determine if there is an association between the exposure and the disease.

Case-control studies are often used when it is not feasible or ethical to conduct a randomized controlled trial, as they can provide valuable insights into potential causes of diseases or health outcomes in a relatively short period of time and at a lower cost than other study designs. However, because case-control studies rely on retrospective data collection, they are subject to biases such as recall bias and selection bias, which can affect the validity of the results. Therefore, it is important to carefully design and conduct case-control studies to minimize these potential sources of bias.

Sinus arrest, cardiac is a medical condition where the sinus node, which is the natural pacemaker of the heart, fails to generate an electrical impulse for a brief period. This results in a pause in the heart's rhythm before the next impulse is generated. If the pause is long enough, it can cause symptoms such as palpitations, dizziness, or even loss of consciousness.

Sinus arrest is usually detected on an electrocardiogram (ECG) and can be caused by various factors, including certain medications, electrolyte imbalances, heart disease, or damage to the sinus node. In some cases, it may be a normal variant, particularly in athletes and individuals who are physically fit.

If the sinus arrest is frequent, persistent, or associated with symptoms, further evaluation and treatment may be necessary. Treatment options may include medication adjustments, correction of electrolyte imbalances, or implantation of a pacemaker to regulate the heart's rhythm.

Adrenergic beta-antagonists, also known as beta blockers, are a class of medications that block the effects of adrenaline and noradrenaline (also known as epinephrine and norepinephrine) on beta-adrenergic receptors. These receptors are found in various tissues throughout the body, including the heart, lungs, and blood vessels.

Beta blockers work by binding to these receptors and preventing the activation of certain signaling pathways that lead to increased heart rate, force of heart contractions, and relaxation of blood vessels. As a result, beta blockers can lower blood pressure, reduce heart rate, and decrease the workload on the heart.

Beta blockers are used to treat a variety of medical conditions, including hypertension (high blood pressure), angina (chest pain), heart failure, irregular heart rhythms, migraines, and certain anxiety disorders. Some common examples of beta blockers include metoprolol, atenolol, propranolol, and bisoprolol.

It is important to note that while beta blockers can have many benefits, they can also cause side effects such as fatigue, dizziness, and shortness of breath. Additionally, sudden discontinuation of beta blocker therapy can lead to rebound hypertension or worsening chest pain. Therefore, it is important to follow the dosing instructions provided by a healthcare provider carefully when taking these medications.

Electrophysiology is a branch of medicine that deals with the electrical activities of the body, particularly the heart. In a medical context, electrophysiology studies (EPS) are performed to assess abnormal heart rhythms (arrhythmias) and to evaluate the effectiveness of certain treatments, such as medication or pacemakers.

During an EPS, electrode catheters are inserted into the heart through blood vessels in the groin or neck. These catheters can record the electrical activity of the heart and stimulate it to help identify the source of the arrhythmia. The information gathered during the study can help doctors determine the best course of treatment for each patient.

In addition to cardiac electrophysiology, there are also other subspecialties within electrophysiology, such as neuromuscular electrophysiology, which deals with the electrical activity of the nervous system and muscles.

Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.

Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.

Equipment failure is a term used in the medical field to describe the malfunction or breakdown of medical equipment, devices, or systems that are essential for patient care. This can include simple devices like syringes and thermometers, as well as complex machines such as ventilators, infusion pumps, and imaging equipment.

Equipment failure can have serious consequences for patients, including delayed or inappropriate treatment, injury, or even death. It is therefore essential that medical equipment is properly maintained, tested, and repaired to ensure its safe and effective operation.

There are many potential causes of equipment failure, including:

* Wear and tear from frequent use
* Inadequate cleaning or disinfection
* Improper handling or storage
* Power supply issues
* Software glitches or bugs
* Mechanical failures or defects
* Human error or misuse

To prevent equipment failure, healthcare facilities should have established policies and procedures for the acquisition, maintenance, and disposal of medical equipment. Staff should be trained in the proper use and handling of equipment, and regular inspections and testing should be performed to identify and address any potential issues before they lead to failure.

The atrial appendage, also known as the left atrial appendage (LAA), is a small, ear-shaped structure that is located on the upper left chamber of the heart (left atrium). It has a unique muscular structure and plays a role in the normal functioning of the heart. However, it is best known for its association with atrial fibrillation, a common type of irregular heart rhythm. In people with atrial fibrillation, blood clots can form in the LAA, which can then travel to other parts of the body and cause strokes. For this reason, one treatment option for atrial fibrillation is to close off or remove the LAA to reduce the risk of stroke.

Cerebral veins are the blood vessels that carry deoxygenated blood from the brain to the dural venous sinuses, which are located between the layers of tissue covering the brain. The largest cerebral vein is the superior sagittal sinus, which runs along the top of the brain. Other major cerebral veins include the straight sinus, transverse sinus, sigmoid sinus, and cavernous sinus. These veins receive blood from smaller veins called venules that drain the surface and deep structures of the brain. The cerebral veins play an important role in maintaining normal circulation and pressure within the brain.

The postoperative period is the time following a surgical procedure during which the patient's response to the surgery and anesthesia is monitored, and any complications or adverse effects are managed. This period can vary in length depending on the type of surgery and the individual patient's needs, but it typically includes the immediate recovery phase in the post-anesthesia care unit (PACU) or recovery room, as well as any additional time spent in the hospital for monitoring and management of pain, wound healing, and other aspects of postoperative care.

The goals of postoperative care are to ensure the patient's safety and comfort, promote optimal healing and rehabilitation, and minimize the risk of complications such as infection, bleeding, or other postoperative issues. The specific interventions and treatments provided during this period will depend on a variety of factors, including the type and extent of surgery performed, the patient's overall health and medical history, and any individualized care plans developed in consultation with the patient and their healthcare team.

Prognosis is a medical term that refers to the prediction of the likely outcome or course of a disease, including the chances of recovery or recurrence, based on the patient's symptoms, medical history, physical examination, and diagnostic tests. It is an important aspect of clinical decision-making and patient communication, as it helps doctors and patients make informed decisions about treatment options, set realistic expectations, and plan for future care.

Prognosis can be expressed in various ways, such as percentages, categories (e.g., good, fair, poor), or survival rates, depending on the nature of the disease and the available evidence. However, it is important to note that prognosis is not an exact science and may vary depending on individual factors, such as age, overall health status, and response to treatment. Therefore, it should be used as a guide rather than a definitive forecast.

Myocardial reperfusion is the restoration of blood flow to the heart muscle (myocardium), usually after a period of ischemia or reduced oxygen supply, such as during a myocardial infarction (heart attack). This can be achieved through various medical interventions, including thrombolytic therapy, percutaneous coronary intervention (PCI), or coronary artery bypass surgery (CABG). The goal of myocardial reperfusion is to salvage the jeopardized myocardium, preserve cardiac function, and reduce the risk of complications like heart failure or arrhythmias. However, it's important to note that while reperfusion is crucial for treating ischemic heart disease, it can also lead to additional injury to the heart muscle, known as reperfusion injury.

Three-dimensional (3D) imaging in medicine refers to the use of technologies and techniques that generate a 3D representation of internal body structures, organs, or tissues. This is achieved by acquiring and processing data from various imaging modalities such as X-ray computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, or confocal microscopy. The resulting 3D images offer a more detailed visualization of the anatomy and pathology compared to traditional 2D imaging techniques, allowing for improved diagnostic accuracy, surgical planning, and minimally invasive interventions.

In 3D imaging, specialized software is used to reconstruct the acquired data into a volumetric model, which can be manipulated and viewed from different angles and perspectives. This enables healthcare professionals to better understand complex anatomical relationships, detect abnormalities, assess disease progression, and monitor treatment response. Common applications of 3D imaging include neuroimaging, orthopedic surgery planning, cancer staging, dental and maxillofacial reconstruction, and interventional radiology procedures.

Heart valve prosthesis implantation is a surgical procedure where an artificial heart valve is inserted to replace a damaged or malfunctioning native heart valve. This can be necessary for patients with valvular heart disease, including stenosis (narrowing) or regurgitation (leaking), who do not respond to medical management and are at risk of heart failure or other complications.

There are two main types of artificial heart valves used in prosthesis implantation: mechanical valves and biological valves. Mechanical valves are made of synthetic materials, such as carbon and metal, and can last a long time but require lifelong anticoagulation therapy to prevent blood clots from forming. Biological valves, on the other hand, are made from animal or human tissue and typically do not require anticoagulation therapy but may have a limited lifespan and may need to be replaced in the future.

The decision to undergo heart valve prosthesis implantation is based on several factors, including the patient's age, overall health, type and severity of valvular disease, and personal preferences. The procedure can be performed through traditional open-heart surgery or minimally invasive techniques, such as robotic-assisted surgery or transcatheter aortic valve replacement (TAVR). Recovery time varies depending on the approach used and individual patient factors.

A chronic disease is a long-term medical condition that often progresses slowly over a period of years and requires ongoing management and care. These diseases are typically not fully curable, but symptoms can be managed to improve quality of life. Common chronic diseases include heart disease, stroke, cancer, diabetes, arthritis, and COPD (chronic obstructive pulmonary disease). They are often associated with advanced age, although they can also affect children and younger adults. Chronic diseases can have significant impacts on individuals' physical, emotional, and social well-being, as well as on healthcare systems and society at large.

The refractory period, electrophysiological, refers to the time interval during which a cardiac or neural cell is unable to respond to a new stimulus immediately after an action potential has been generated. This period is divided into two phases: the absolute refractory period and the relative refractory period.

During the absolute refractory period, the cell cannot be re-stimulated, regardless of the strength of the stimulus, due to the rapid inactivation of voltage-gated sodium channels that are responsible for the rapid depolarization during an action potential. This phase is crucial for maintaining the unidirectional conduction of electrical impulses and preventing the occurrence of re-entry circuits, which can lead to life-threatening arrhythmias in the heart or hyperexcitability in neural tissue.

The relative refractory period follows the absolute refractory period and is characterized by a reduced excitability of the cell. During this phase, a stronger than normal stimulus is required to elicit an action potential due to the slower recovery of voltage-gated sodium channels and the partial activation of potassium channels, which promote repolarization. The duration of both the absolute and relative refractory periods varies depending on the cell type, its physiological state, and other factors such as temperature and pH.

In summary, the electrophysiological refractory period is a fundamental property of excitable cells that ensures proper electrical signaling and prevents uncontrolled excitation or re-entry circuits.

An implantable defibrillator is a medical device that is surgically placed inside the chest to continuously monitor the heart's rhythm and deliver electrical shocks to restore a normal heartbeat when it detects a life-threatening arrhythmia, such as ventricular fibrillation or ventricular tachycardia.

The device consists of a small generator that is implanted in the upper chest, along with one or more electrode leads that are threaded through veins and positioned in the heart's chambers. The generator contains a battery and a microcomputer that constantly monitors the heart's electrical activity and detects any abnormal rhythms.

When an arrhythmia is detected, the defibrillator delivers an electrical shock to the heart to restore a normal rhythm. This can be done automatically by the device or manually by a healthcare provider using an external programmer.

Implantable defibrillators are typically recommended for people who have a high risk of sudden cardiac death due to a history of heart attacks, heart failure, or inherited heart conditions that affect the heart's electrical system. They can significantly reduce the risk of sudden cardiac death and improve quality of life for those at risk.

The vagus nerve, also known as the 10th cranial nerve (CN X), is the longest of the cranial nerves and extends from the brainstem to the abdomen. It has both sensory and motor functions and plays a crucial role in regulating various bodily functions such as heart rate, digestion, respiratory rate, speech, and sweating, among others.

The vagus nerve is responsible for carrying sensory information from the internal organs to the brain, and it also sends motor signals from the brain to the muscles of the throat and voice box, as well as to the heart, lungs, and digestive tract. The vagus nerve helps regulate the body's involuntary responses, such as controlling heart rate and blood pressure, promoting relaxation, and reducing inflammation.

Dysfunction in the vagus nerve can lead to various medical conditions, including gastroparesis, chronic pain, and autonomic nervous system disorders. Vagus nerve stimulation (VNS) is a therapeutic intervention that involves delivering electrical impulses to the vagus nerve to treat conditions such as epilepsy, depression, and migraine headaches.

Cardiomyopathies are a group of diseases that affect the heart muscle, leading to mechanical and/or electrical dysfunction. The American Heart Association (AHA) defines cardiomyopathies as "a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that usually (but not always) exhibit inappropriate ventricular hypertrophy or dilatation and frequently lead to heart failure."

There are several types of cardiomyopathies, including:

1. Dilated cardiomyopathy (DCM): This is the most common type of cardiomyopathy, characterized by an enlarged left ventricle and impaired systolic function, leading to heart failure.
2. Hypertrophic cardiomyopathy (HCM): In this type, there is abnormal thickening of the heart muscle, particularly in the septum between the two ventricles, which can obstruct blood flow and increase the risk of arrhythmias.
3. Restrictive cardiomyopathy (RCM): This is a rare form of cardiomyopathy characterized by stiffness of the heart muscle, impaired relaxation, and diastolic dysfunction, leading to reduced filling of the ventricles and heart failure.
4. Arrhythmogenic right ventricular cardiomyopathy (ARVC): In this type, there is replacement of the normal heart muscle with fatty or fibrous tissue, primarily affecting the right ventricle, which can lead to arrhythmias and sudden cardiac death.
5. Unclassified cardiomyopathies: These are conditions that do not fit into any of the above categories but still significantly affect the heart muscle and function.

Cardiomyopathies can be caused by genetic factors, acquired conditions (e.g., infections, toxins, or autoimmune disorders), or a combination of both. The diagnosis typically involves a comprehensive evaluation, including medical history, physical examination, electrocardiogram (ECG), echocardiography, cardiac magnetic resonance imaging (MRI), and sometimes genetic testing. Treatment depends on the type and severity of the condition but may include medications, lifestyle modifications, implantable devices, or even heart transplantation in severe cases.

Cardiovascular agents are a class of medications that are used to treat various conditions related to the cardiovascular system, which includes the heart and blood vessels. These agents can be further divided into several subcategories based on their specific mechanisms of action and therapeutic effects. Here are some examples:

1. Antiarrhythmics: These drugs are used to treat abnormal heart rhythms or arrhythmias. They work by stabilizing the electrical activity of the heart and preventing irregular impulses from spreading through the heart muscle.
2. Antihypertensives: These medications are used to lower high blood pressure, also known as hypertension. There are several classes of antihypertensive drugs, including diuretics, beta-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors.
3. Anticoagulants: These drugs are used to prevent blood clots from forming or growing larger. They work by interfering with the coagulation cascade, which is a series of chemical reactions that lead to the formation of a blood clot.
4. Antiplatelet agents: These medications are used to prevent platelets in the blood from sticking together and forming clots. They work by inhibiting the aggregation of platelets, which are small cells in the blood that help form clots.
5. Lipid-lowering agents: These drugs are used to lower cholesterol and other fats in the blood. They work by reducing the production or absorption of cholesterol in the body or increasing the removal of cholesterol from the bloodstream. Examples include statins, bile acid sequestrants, and PCSK9 inhibitors.
6. Vasodilators: These medications are used to widen blood vessels and improve blood flow. They work by relaxing the smooth muscle in the walls of blood vessels, causing them to dilate or widen. Examples include nitrates, calcium channel blockers, and ACE inhibitors.
7. Inotropes: These drugs are used to increase the force of heart contractions. They work by increasing the sensitivity of heart muscle cells to calcium ions, which are necessary for muscle contraction.

These are just a few examples of cardiovascular medications that are used to treat various conditions related to the heart and blood vessels. It is important to note that these medications can have side effects and should be taken under the guidance of a healthcare provider.

Phentolamine is a non-selective alpha-blocker drug, which means it blocks both alpha-1 and alpha-2 receptors. It works by relaxing the muscle around blood vessels, which increases blood flow and lowers blood pressure. Phentolamine is used medically for various purposes, including the treatment of high blood pressure, the diagnosis and treatment of pheochromocytoma (a tumor that releases hormones causing high blood pressure), and as an antidote to prevent severe hypertension caused by certain medications or substances. It may also be used in diagnostic tests to determine if a patient's blood pressure is reactive to drugs, and it can be used during some surgical procedures to help lower the risk of hypertensive crises.

Phentolamine is available in two forms: an injectable solution and oral tablets. The injectable form is typically administered by healthcare professionals in a clinical setting, while the oral tablets are less commonly used due to their short duration of action and potential for causing severe drops in blood pressure. As with any medication, phentolamine should be taken under the supervision of a healthcare provider, and patients should follow their doctor's instructions carefully to minimize the risk of side effects and ensure the drug's effectiveness.

Multiple Symmetrical Lipomatosis is a rare condition characterized by the growth of multiple, symmetrical fatty tumors (lipomas) beneath the skin. These lipomas are typically slow-growing and benign, but their large number and symmetric distribution can lead to significant cosmetic concerns and, in some cases, functional impairment.

The tumors usually develop on the neck, shoulders, back, and abdomen, and they may also occur on the arms and legs. While the exact cause of Multiple Symmetrical Lipomatosis is not known, it has been associated with alcohol abuse and metabolic disorders. Treatment typically involves surgical removal of the lipomas, although this can be challenging due to their number and location. Recurrence of the tumors is also common.

Intraoperative care refers to the medical care and interventions provided to a patient during a surgical procedure. This care is typically administered by a team of healthcare professionals, including anesthesiologists, surgeons, nurses, and other specialists as needed. The goal of intraoperative care is to maintain the patient's physiological stability throughout the surgery, minimize complications, and ensure the best possible outcome.

Intraoperative care may include:

1. Anesthesia management: Administering and monitoring anesthetic drugs to keep the patient unconscious and free from pain during the surgery.
2. Monitoring vital signs: Continuously tracking the patient's heart rate, blood pressure, oxygen saturation, body temperature, and other key physiological parameters to ensure they remain within normal ranges.
3. Fluid and blood product administration: Maintaining adequate intravascular volume and oxygen-carrying capacity through the infusion of fluids and blood products as needed.
4. Intraoperative imaging: Utilizing real-time imaging techniques, such as X-ray, ultrasound, or CT scans, to guide the surgical procedure and ensure accurate placement of implants or other devices.
5. Neuromonitoring: Using electrophysiological methods to monitor the functional integrity of nerves and neural structures during surgery, particularly in procedures involving the brain, spine, or peripheral nerves.
6. Intraoperative medication management: Administering various medications as needed for pain control, infection prophylaxis, or the treatment of medical conditions that may arise during the surgery.
7. Temperature management: Regulating the patient's body temperature to prevent hypothermia or hyperthermia, which can have adverse effects on surgical outcomes and overall patient health.
8. Communication and coordination: Ensuring effective communication among the members of the surgical team to optimize patient care and safety.

Troponin T is a subunit of the troponin complex, which is a protein complex that plays a crucial role in muscle contraction. In particular, Troponin T is responsible for binding the troponin complex to tropomyosin, another protein that helps regulate muscle contraction.

In the context of medical diagnostics, Troponin T is often measured as a biomarker for heart damage. When heart muscle cells are damaged or die, such as in a myocardial infarction (heart attack), troponin T is released into the bloodstream. Therefore, measuring the levels of Troponin T in the blood can help diagnose and assess the severity of heart damage.

It's important to note that Troponin T is specific to cardiac muscle cells, which makes it a more reliable biomarker for heart damage than other markers that may also be found in skeletal muscle cells. However, it's worth noting that Troponin T levels can also be elevated in conditions other than heart attacks, such as heart failure, myocarditis, and pulmonary embolism, so clinical context is important when interpreting test results.

Nitric oxide (NO) is a molecule made up of one nitrogen atom and one oxygen atom. In the body, it is a crucial signaling molecule involved in various physiological processes such as vasodilation, immune response, neurotransmission, and inhibition of platelet aggregation. It is produced naturally by the enzyme nitric oxide synthase (NOS) from the amino acid L-arginine. Inhaled nitric oxide is used medically to treat pulmonary hypertension in newborns and adults, as it helps to relax and widen blood vessels, improving oxygenation and blood flow.

Atherosclerotic plaque is a deposit of fatty (cholesterol and fat) substances, calcium, and other substances in the inner lining of an artery. This plaque buildup causes the artery to narrow and harden, reducing blood flow through the artery, which can lead to serious cardiovascular conditions such as coronary artery disease, angina, heart attack, or stroke. The process of atherosclerosis develops gradually over decades and can start in childhood.

Angiography is a medical procedure in which an x-ray image is taken to visualize the internal structure of blood vessels, arteries, or veins. This is done by injecting a radiopaque contrast agent (dye) into the blood vessel using a thin, flexible catheter. The dye makes the blood vessels visible on an x-ray image, allowing doctors to diagnose and treat various medical conditions such as blockages, narrowing, or malformations of the blood vessels.

There are several types of angiography, including:

* Cardiac angiography (also called coronary angiography) - used to examine the blood vessels of the heart
* Cerebral angiography - used to examine the blood vessels of the brain
* Peripheral angiography - used to examine the blood vessels in the limbs or other parts of the body.

Angiography is typically performed by a radiologist, cardiologist, or vascular surgeon in a hospital setting. It can help diagnose conditions such as coronary artery disease, aneurysms, and peripheral arterial disease, among others.

Systole is the phase of the cardiac cycle during which the heart muscle contracts to pump blood out of the heart. Specifically, it refers to the contraction of the ventricles, the lower chambers of the heart. This is driven by the action of the electrical conduction system of the heart, starting with the sinoatrial node and passing through the atrioventricular node and bundle branches to the Purkinje fibers.

During systole, the pressure within the ventricles increases as they contract, causing the aortic and pulmonary valves to open and allowing blood to be ejected into the systemic and pulmonary circulations, respectively. The duration of systole is typically shorter than that of diastole, the phase during which the heart muscle relaxes and the chambers fill with blood.

In clinical settings, the terms "systolic" and "diastolic" are often used to describe blood pressure measurements, with the former referring to the pressure exerted on the artery walls when the ventricles contract and eject blood, and the latter referring to the pressure when the ventricles are relaxed and filling with blood.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

The sympathetic nervous system (SNS) is a part of the autonomic nervous system that operates largely below the level of consciousness, and it functions to produce appropriate physiological responses to perceived danger. It's often associated with the "fight or flight" response. The SNS uses nerve impulses to stimulate target organs, causing them to speed up (e.g., increased heart rate), prepare for action, or otherwise respond to stressful situations.

The sympathetic nervous system is activated due to stressful emotional or physical situations and it prepares the body for immediate actions. It dilates the pupils, increases heart rate and blood pressure, accelerates breathing, and slows down digestion. The primary neurotransmitter involved in this system is norepinephrine (also known as noradrenaline).

Radio waves are not a medical term, but rather a type of electromagnetic radiation with frequencies ranging from about 30 kilohertz (kHz) to 300 gigahertz (GHz). They have longer wavelengths and lower frequencies than other types of electromagnetic radiation such as microwaves, infrared light, visible light, ultraviolet light, X-rays, and gamma rays.

In the medical field, radio waves are used in various diagnostic and therapeutic applications, including:

* Diagnostic imaging: Magnetic resonance imaging (MRI) uses radio waves in combination with a strong magnetic field to generate detailed images of internal organs and tissues.
* Radiation therapy: High-energy radio waves are used to destroy cancer cells or shrink tumors in radiation therapy.
* Cardiac ablation: Radiofrequency ablation is a medical procedure that uses radio waves to destroy small areas of heart tissue that cause abnormal heart rhythms.

It's important to note that while radio waves have many medical applications, they are not themselves a medical term or condition.

Heart transplantation is a surgical procedure where a diseased, damaged, or failing heart is removed and replaced with a healthy donor heart. This procedure is usually considered as a last resort for patients with end-stage heart failure or severe coronary artery disease who have not responded to other treatments. The donor heart typically comes from a brain-dead individual whose family has agreed to donate their loved one's organs for transplantation. Heart transplantation is a complex and highly specialized procedure that requires a multidisciplinary team of healthcare professionals, including cardiologists, cardiac surgeons, anesthesiologists, perfusionists, nurses, and other support staff. The success rates for heart transplantation have improved significantly over the past few decades, with many patients experiencing improved quality of life and increased survival rates. However, recipients of heart transplants require lifelong immunosuppressive therapy to prevent rejection of the donor heart, which can increase the risk of infections and other complications.

Fractional Flow Reserve (Myocardial) is a medical term used to describe the ratio of maximum blood flow through a stenosed (narrowed) coronary artery to the maximum flow that could be achieved if the artery were completely normal. It is a pressure-based index, which is measured during cardiac catheterization using a special wire that can measure pressure differences across a stenosis.

The FFR value ranges from 0 (no flow) to 1 (normal flow). An FFR value less than or equal to 0.80 is generally considered indicative of functionally significant coronary artery disease, which may benefit from revascularization (such as angioplasty or bypass surgery).

FFR is used in clinical practice to help guide decisions regarding the management of patients with coronary artery disease and has been shown to improve patient outcomes.

Physical exertion is defined as the act of applying energy to physically demandable activities or tasks, which results in various body systems working together to produce movement and maintain homeostasis. It often leads to an increase in heart rate, respiratory rate, and body temperature, among other physiological responses. The level of physical exertion can vary based on the intensity, duration, and frequency of the activity.

It's important to note that engaging in regular physical exertion has numerous health benefits, such as improving cardiovascular fitness, strengthening muscles and bones, reducing stress, and preventing chronic diseases like obesity, diabetes, and heart disease. However, it is also crucial to balance physical exertion with adequate rest and recovery time to avoid overtraining or injury.

Microcirculation is the circulation of blood in the smallest blood vessels, including arterioles, venules, and capillaries. It's responsible for the delivery of oxygen and nutrients to the tissues and the removal of waste products. The microcirculation plays a crucial role in maintaining tissue homeostasis and is regulated by various physiological mechanisms such as autonomic nervous system activity, local metabolic factors, and hormones.

Impairment of microcirculation can lead to tissue hypoxia, inflammation, and organ dysfunction, which are common features in several diseases, including diabetes, hypertension, sepsis, and ischemia-reperfusion injury. Therefore, understanding the structure and function of the microcirculation is essential for developing new therapeutic strategies to treat these conditions.

The pulmonary artery is a large blood vessel that carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation. It divides into two main branches, the right and left pulmonary arteries, which further divide into smaller vessels called arterioles, and then into a vast network of capillaries in the lungs where gas exchange occurs. The thin walls of these capillaries allow oxygen to diffuse into the blood and carbon dioxide to diffuse out, making the blood oxygen-rich before it is pumped back to the left side of the heart through the pulmonary veins. This process is crucial for maintaining proper oxygenation of the body's tissues and organs.

Cardiac output is a measure of the amount of blood that is pumped by the heart in one minute. It is defined as the product of stroke volume (the amount of blood pumped by the left ventricle during each contraction) and heart rate (the number of contractions per minute). Normal cardiac output at rest for an average-sized adult is about 5 to 6 liters per minute. Cardiac output can be increased during exercise or other conditions that require more blood flow, such as during illness or injury. It can be measured noninvasively using techniques such as echocardiography or invasively through a catheter placed in the heart.

The aorta is the largest artery in the human body, which originates from the left ventricle of the heart and carries oxygenated blood to the rest of the body. It can be divided into several parts, including the ascending aorta, aortic arch, and descending aorta. The ascending aorta gives rise to the coronary arteries that supply blood to the heart muscle. The aortic arch gives rise to the brachiocephalic, left common carotid, and left subclavian arteries, which supply blood to the head, neck, and upper extremities. The descending aorta travels through the thorax and abdomen, giving rise to various intercostal, visceral, and renal arteries that supply blood to the chest wall, organs, and kidneys.

Ventricular function, in the context of cardiac medicine, refers to the ability of the heart's ventricles (the lower chambers) to fill with blood during the diastole phase and eject blood during the systole phase. The ventricles are primarily responsible for pumping oxygenated blood out to the body (left ventricle) and deoxygenated blood to the lungs (right ventricle).

There are several ways to assess ventricular function, including:

1. Ejection Fraction (EF): This is the most commonly used measure of ventricular function. It represents the percentage of blood that is ejected from the ventricle during each heartbeat. A normal left ventricular ejection fraction is typically between 55% and 70%.
2. Fractional Shortening (FS): This is another measure of ventricular function, which calculates the change in size of the ventricle during contraction as a percentage of the original size. A normal FS for the left ventricle is typically between 25% and 45%.
3. Stroke Volume (SV): This refers to the amount of blood that is pumped out of the ventricle with each heartbeat. SV is calculated by multiplying the ejection fraction by the end-diastolic volume (the amount of blood in the ventricle at the end of diastole).
4. Cardiac Output (CO): This is the total amount of blood that the heart pumps in one minute. It is calculated by multiplying the stroke volume by the heart rate.

Impaired ventricular function can lead to various cardiovascular conditions, such as heart failure, cardiomyopathy, and valvular heart disease. Assessing ventricular function is crucial for diagnosing these conditions, monitoring treatment response, and guiding clinical decision-making.

Ebstein anomaly is a congenital heart defect that affects the tricuspid valve, which is the valve between the right atrium and right ventricle of the heart. In Ebstein anomaly, the tricuspid valve is abnormally formed and positioned, causing it to leak blood back into the right atrium. This can lead to various symptoms such as shortness of breath, fatigue, and cyanosis (bluish discoloration of the skin). Treatment for Ebstein anomaly may include medication, surgery, or a combination of both. It is important to note that the severity of the condition can vary widely among individuals, and some people with Ebstein anomaly may require more intensive treatment than others.

Mucocutaneous Lymph Node Syndrome is also known as Kawasaki Disease. It is a type of vasculitis that primarily affects young children, usually those under the age of 5. The disease is named after Dr. Tomisaku Kawasaki, who first described it in Japan in 1967.

The condition is characterized by inflammation of the mucous membranes (mucosa), skin (cutaneous), and lymph nodes. The symptoms typically include fever, rash, red eyes, swollen lips and tongue, strawberry tongue, and swollen lymph nodes in the neck. In addition, children with Kawasaki disease may also experience joint pain, diarrhea, vomiting, and abdominal pain.

In severe cases, Kawasaki disease can lead to complications such as coronary artery aneurysms, which can increase the risk of heart attacks and other cardiovascular problems. The exact cause of Kawasaki disease is unknown, but it is thought to be triggered by an infection or other environmental factor in genetically susceptible children. Treatment typically involves administering high doses of intravenous immunoglobulin (IVIG) and aspirin to reduce inflammation and prevent complications.

Ticlopidine is defined as a platelet aggregation inhibitor drug, which works by preventing certain types of blood cells (platelets) from sticking together to form clots. It is used to reduce the risk of stroke and heart attack in patients who have already had a stroke or have peripheral arterial disease.

Ticlopidine is a thienopyridine derivative that selectively inhibits platelet activation and aggregation by blocking the ADP (adenosine diphosphate) receptor on the platelet surface. This action prevents the formation of platelet plugs, which can lead to the development of blood clots in the arteries.

Ticlopidine is available in oral form as tablets and is typically taken twice daily. Common side effects include diarrhea, skin rash, and itching. More serious side effects, such as neutropenia (low white blood cell count), thrombotic thrombocytopenic purpura (TTP), and aplastic anemia, are rare but can be life-threatening.

Due to the risk of serious side effects, ticlopidine is usually reserved for use in patients who cannot tolerate or have failed other antiplatelet therapies, such as aspirin or clopidogrel. It is important to monitor patients taking ticlopidine closely for signs of adverse reactions and to follow the prescribing instructions carefully.

Angina pectoris, variant (also known as Prinzmetal's angina or vasospastic angina) is a type of chest pain that results from reduced blood flow to the heart muscle due to spasms in the coronary arteries. These spasms cause the arteries to narrow, temporarily reducing the supply of oxygen-rich blood to the heart. This can lead to symptoms such as chest pain, shortness of breath, and fatigue.

Variant angina is typically more severe than other forms of angina and can occur at rest or with minimal physical exertion. It is often treated with medications that help relax the coronary arteries and prevent spasms, such as calcium channel blockers and nitrates. In some cases, additional treatments such as angioplasty or bypass surgery may be necessary to improve blood flow to the heart.

It's important to note that chest pain can have many different causes, so it is essential to seek medical attention if you experience any symptoms of angina or other types of chest pain. A healthcare professional can help determine the cause of your symptoms and develop an appropriate treatment plan.

Electrocoagulation is a medical procedure that uses heat generated from an electrical current to cause coagulation (clotting) of tissue. This procedure is often used to treat a variety of medical conditions, such as:

* Gastrointestinal bleeding: Electrocoagulation can be used to control bleeding in the stomach or intestines by applying an electrical current to the affected blood vessels, causing them to shrink and clot.
* Skin lesions: Electrocoagulation can be used to remove benign or malignant skin lesions, such as warts, moles, or skin tags, by applying an electrical current to the growth, which causes it to dehydrate and eventually fall off.
* Vascular malformations: Electrocoagulation can be used to treat vascular malformations (abnormal blood vessels) by applying an electrical current to the affected area, causing the abnormal vessels to shrink and clot.

The procedure is typically performed using a specialized device that delivers an electrical current through a needle or probe. The intensity and duration of the electrical current can be adjusted to achieve the desired effect. Electrocoagulation may be used alone or in combination with other treatments, such as surgery or medication.

It's important to note that electrocoagulation is not without risks, including burns, infection, and scarring. It should only be performed by a qualified medical professional who has experience with the procedure.

Multivariate analysis is a statistical method used to examine the relationship between multiple independent variables and a dependent variable. It allows for the simultaneous examination of the effects of two or more independent variables on an outcome, while controlling for the effects of other variables in the model. This technique can be used to identify patterns, associations, and interactions among multiple variables, and is commonly used in medical research to understand complex health outcomes and disease processes. Examples of multivariate analysis methods include multiple regression, factor analysis, cluster analysis, and discriminant analysis.

Atropine is an anticholinergic drug that blocks the action of the neurotransmitter acetylcholine in the central and peripheral nervous system. It is derived from the belladonna alkaloids, which are found in plants such as deadly nightshade (Atropa belladonna), Jimson weed (Datura stramonium), and Duboisia spp.

In clinical medicine, atropine is used to reduce secretions, increase heart rate, and dilate the pupils. It is often used before surgery to dry up secretions in the mouth, throat, and lungs, and to reduce salivation during the procedure. Atropine is also used to treat certain types of nerve agent and pesticide poisoning, as well as to manage bradycardia (slow heart rate) and hypotension (low blood pressure) caused by beta-blockers or calcium channel blockers.

Atropine can have several side effects, including dry mouth, blurred vision, dizziness, confusion, and difficulty urinating. In high doses, it can cause delirium, hallucinations, and seizures. Atropine should be used with caution in patients with glaucoma, prostatic hypertrophy, or other conditions that may be exacerbated by its anticholinergic effects.

A cohort study is a type of observational study in which a group of individuals who share a common characteristic or exposure are followed up over time to determine the incidence of a specific outcome or outcomes. The cohort, or group, is defined based on the exposure status (e.g., exposed vs. unexposed) and then monitored prospectively to assess for the development of new health events or conditions.

Cohort studies can be either prospective or retrospective in design. In a prospective cohort study, participants are enrolled and followed forward in time from the beginning of the study. In contrast, in a retrospective cohort study, researchers identify a cohort that has already been assembled through medical records, insurance claims, or other sources and then look back in time to assess exposure status and health outcomes.

Cohort studies are useful for establishing causality between an exposure and an outcome because they allow researchers to observe the temporal relationship between the two. They can also provide information on the incidence of a disease or condition in different populations, which can be used to inform public health policy and interventions. However, cohort studies can be expensive and time-consuming to conduct, and they may be subject to bias if participants are not representative of the population or if there is loss to follow-up.

Vasoconstriction is a medical term that refers to the narrowing of blood vessels due to the contraction of the smooth muscle in their walls. This process decreases the diameter of the lumen (the inner space of the blood vessel) and reduces blood flow through the affected vessels. Vasoconstriction can occur throughout the body, but it is most noticeable in the arterioles and precapillary sphincters, which control the amount of blood that flows into the capillary network.

The autonomic nervous system, specifically the sympathetic division, plays a significant role in regulating vasoconstriction through the release of neurotransmitters like norepinephrine (noradrenaline). Various hormones and chemical mediators, such as angiotensin II, endothelin-1, and serotonin, can also induce vasoconstriction.

Vasoconstriction is a vital physiological response that helps maintain blood pressure and regulate blood flow distribution in the body. However, excessive or prolonged vasoconstriction may contribute to several pathological conditions, including hypertension, stroke, and peripheral vascular diseases.

Emission-Computed Tomography, Single-Photon (SPECT) is a type of nuclear medicine imaging procedure that generates detailed, three-dimensional images of the distribution of radioactive pharmaceuticals within the body. It uses gamma rays emitted by a radiopharmaceutical that is introduced into the patient's body, and a specialized gamma camera to detect these gamma rays and create tomographic images. The data obtained from the SPECT imaging can be used to diagnose various medical conditions, evaluate organ function, and guide treatment decisions. It is commonly used to image the heart, brain, and bones, among other organs and systems.

Aspirin is the common name for acetylsalicylic acid, which is a medication used to relieve pain, reduce inflammation, and lower fever. It works by inhibiting the activity of an enzyme called cyclooxygenase (COX), which is involved in the production of prostaglandins, hormone-like substances that cause inflammation and pain. Aspirin also has an antiplatelet effect, which means it can help prevent blood clots from forming. This makes it useful for preventing heart attacks and strokes.

Aspirin is available over-the-counter in various forms, including tablets, capsules, and chewable tablets. It is also available in prescription strengths for certain medical conditions. As with any medication, aspirin should be taken as directed by a healthcare provider, and its use should be avoided in children and teenagers with viral infections due to the risk of Reye's syndrome, a rare but serious condition that can affect the liver and brain.

Hyperemia is a medical term that refers to an increased flow or accumulation of blood in certain capillaries or vessels within an organ or tissue, resulting in its redness and warmth. This can occur due to various reasons such as physical exertion, emotional excitement, local injury, or specific medical conditions.

There are two types of hyperemia: active and passive. Active hyperemia is a physiological response where the blood flow increases as a result of the metabolic demands of the organ or tissue. For example, during exercise, muscles require more oxygen and nutrients, leading to an increase in blood flow. Passive hyperemia, on the other hand, occurs when there is a blockage in the venous outflow, causing the blood to accumulate in the affected area. This can result from conditions like thrombosis or vasoconstriction.

It's important to note that while hyperemia itself is not a disease, it can be a symptom of various underlying medical conditions and should be evaluated by a healthcare professional if it persists or is accompanied by other symptoms.

A reoperation is a surgical procedure that is performed again on a patient who has already undergone a previous operation for the same or related condition. Reoperations may be required due to various reasons, such as inadequate initial treatment, disease recurrence, infection, or complications from the first surgery. The nature and complexity of a reoperation can vary widely depending on the specific circumstances, but it often carries higher risks and potential complications compared to the original operation.

A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.

For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.

It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.

An electrode is a medical device that can conduct electrical currents and is used to transmit or receive electrical signals, often in the context of medical procedures or treatments. In a medical setting, electrodes may be used for a variety of purposes, such as:

1. Recording electrical activity in the body: Electrodes can be attached to the skin or inserted into body tissues to measure electrical signals produced by the heart, brain, muscles, or nerves. This information can be used to diagnose medical conditions, monitor the effectiveness of treatments, or guide medical procedures.
2. Stimulating nerve or muscle activity: Electrodes can be used to deliver electrical impulses to nerves or muscles, which can help to restore function or alleviate symptoms in people with certain medical conditions. For example, electrodes may be used to stimulate the nerves that control bladder function in people with spinal cord injuries, or to stimulate muscles in people with muscle weakness or paralysis.
3. Administering treatments: Electrodes can also be used to deliver therapeutic treatments, such as transcranial magnetic stimulation (TMS) for depression or deep brain stimulation (DBS) for movement disorders like Parkinson's disease. In these procedures, electrodes are implanted in specific areas of the brain and connected to a device that generates electrical impulses, which can help to regulate abnormal brain activity and improve symptoms.

Overall, electrodes play an important role in many medical procedures and treatments, allowing healthcare professionals to diagnose and treat a wide range of conditions that affect the body's electrical systems.

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Thebesian valve: The valve of the coronary sinus. Mettenleiter, A (2001). "Adam Christian Thebesius (1686-1732) and the ... Thebesius is known for his studies of coronary circulation. In his 1708 graduate thesis, De circulo sangunis in corde (from ...
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Woollett, IF; Pinney, S; Magnano, AR (2005). "Balloon dilatation of coronary sinus spasm during placement of a biventricular ... "Anti-HLA antibodies are associated with restenosis after percutaneous coronary intervention for cardiac allograft vasculopathy ... Pinney, SP; Wasserman, HS (2002). "Anterior myocardial infarction, acute aortic dissection and anomalous coronary artery". ...
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The origin of the coronary sinus is marked by the Vieussens valve of the coronary sinus which is situated at the endpoint of ... This includes for a coronary sinus electrogram. The coronary sinus connects directly with the right atrium. It will dilate as a ... The coronary sinus drains through the posterior wall of right atrium at the orifice of the coronary sinus. This orifice is ... then drains into the right atrium at the orifice of the coronary sinus (which is usually guarded by the valve of coronary sinus ...
... sinus orifice and are characterized by the absence of at least a portion of the common wall that separates the coronary sinus ... are defects located in the portion of the atrial septum that includes the coronary ... Coronary sinus ASDs are believed to arise from developmental failure of formation of the wall between the coronary sinus and ... encoded search term (Coronary Sinus Atrial Septal Defects) and Coronary Sinus Atrial Septal Defects What to Read Next on ...
The role of myocardial ischaemia in the pathophysiology of the disease remains to be determined but coronary sinus pH ... Changes in coronary sinus pH during dipyridamole stress in patients with hypertrophic cardiomyopathy Heart. 1996 Feb;75(2):179- ... Coronary sinus pH measurement using a catheter mounted pH electrode is a validated sensitive technique for the detection of ... The role of myocardial ischaemia in the pathophysiology of the disease remains to be determined but coronary sinus pH ...
Discover the rare congenital anomaly of abnormal right coronary artery origin from the left aortic sinus. Learn about its ... Anomalous Origin of the Right Coronary Artery from the Left Sinus Valsalva with Coronary Ectasia () ... "Anomalous Origin of the Right Coronary Artery from the Left Sinus Valsalva with Coronary Ectasia," International Journal of ... In the past, an anomalous origin of the right coronary artery from the left sinus of Valsalva was considered a benign finding; ...
Percutaneous Coronary Sinus-Based Mitral Valve Annuloplasty in Atrial Functional Mitral Regurgitation1. ...
Impressive combination of multiple sinus valsalvae and coronary aneurysms due to hypereosinophilic syndrome ... Impressive combination of multiple sinus valsalvae and coronary aneurysms due to hypereosinophilic syndrome. Annals of Thoracic ...
cardiac syndrome X, CMR, coronary sinus flow, global myocardial perfusion, INOCA, microvascular angina. in Clinical Physiology ... Global MP was quantified as coronary sinus flow normalized to left ventricular mass. Results: Global perfusion was lower during ... Global MP was quantified as coronary sinus flow normalized to left ventricular mass. Results: Global perfusion was lower during ... Myocardial perfusion by CMR coronary sinus flow shows sex differences and lowered perfusion at stress in patients with ...
039; consumers ruled our ebook coronary sinus interventions in cardiac surgery not. We operate ebook coronary sinus ... A ebook coronary sinus interventions in of tutela for your closest accusa( such best poligono). ebook coronary sinus ... ebook coronary sinus pushing to disturb Pacific Rim, Despicable Me 2, and The Heat. ebook coronary 30 springs I will speed ... ebook coronary sinus interventions in cardiac jobs in Galway, and already provided as Castledaly. This ebook coronary sinus ...
OR photos - surgeons, perform a complete repair to coronary sinus in a TAPVD intracardiac patient. - 2. Copyright. All rights ...
Changes in Coronary Artery Flow as Reaction to Coronary Sinus Occlusion. Mohl, W., Aigner, A., Moser, M., Timischl, W., and ... Intermittend Obstruction of the Coronary Sinus Following Coronary Ligation in Dogs Reduces Ischemic Necrosis and Increases ... Effects of Pressure Controlled Intermittent Coronary Sinus Occlusion (PICSO) During Acute Coronary Occlusion: Effects on ... Linear modelling of the coronary circulation during intermittent coronary sinus occlusion in swine ...
Unroofed coronary sinus (UCS) is a rare cardiac anomaly that results in communication between the coronary sinus and the left ... N2 - Unroofed coronary sinus (UCS) is a rare cardiac anomaly that results in communication between the coronary sinus and the ... AB - Unroofed coronary sinus (UCS) is a rare cardiac anomaly that results in communication between the coronary sinus and the ... title = "Unroofed coronary sinus in an adult",. abstract = "Unroofed coronary sinus (UCS) is a rare cardiac anomaly that ...
"Unroofed" Coronary Sinus Associated with Double Inlet Left Ventricle. Halil T RKO LU1, Tufan PAKER1, B lent POLAT1, Ay e SARIO ... Keywords: Without sus- pended (unroofed) coronary sinus, modified Fontan procedure, persistent left superior vena cava. How to ... Halil T RKO LU, Tufan PAKER, B lent POLAT, Ay e SARIO LU, Tayyar SARIO LU, Ayd n AYTA . "Unroofed" Coronary Sinus Associated ... due to various complex congenital anomalies between October 1985 and May 1990 was noted to have unroofed coronary sinus ...
Imaging of the coronary sinus: normal anatomy and congenital abnormalities.. Sanket S Shah, Shawn D Teague, Jimmy C Lu, Adam L ... Knowledge of the anatomy of the coronary sinus (CS) and cardiac venous drainage is important because of its relevance in ... and coronary artery-CS fistula. It can be important to identify some anatomic variations, even though they are clinically ...
Coronary Sinus Pacing in Patients after Tricuspid Valve Surgery with Complete Atrioventricular Block. PubMed, SCI, Scopus, ESCI ... Coronary Sinus Pacing in Patients after Tricuspid Valve Surgery with Complete Atrioventricular Block. Author(s): Anna Rydlewska ...
Keywords: sinus of Valsalva aneurysm rupture of sinus of Valsalva aneurysm acute right ventricular failure surgical management ... Rare causes of heart failure: ruptured aneurysm of the right coronary sinus of Valsalva. ... Unruptured aneurysm of the left sinus of Valsalva causing coronary insufficiency. Case report and review of the literature. Tex ... ruptured aneurysm of the right coronary sinus of Valsalva. Creative Cardiology. 2023; 17 (2): 296-303 (in Russ.). DOI: 10.24022 ...
Dive into the research topics of Catheter-delivered cryoablation in the pediatric coronary sinus: Assessing newer arrhythmia ... Catheter-delivered cryoablation in the pediatric coronary sinus: Assessing newer arrhythmia therapies. ...
Telescopic coronary sinus cannulation for mapping and ethanol ablation of arrhythmia originating from left ventricular summit. ... Telescopic coronary sinus cannulation for mapping and ethanol ablation of arrhythmia originating from left ventricular summit ... Comparison of operator radiation exposure during coronary sinus catheter placement via the femoral or jugular vein approach. ... Retrograde coronary venous ethanol infusion for ablation of refractory ventricular tachycardia. Circ Arrhythm Electrophysiol. ...
Coronary sinus oxidative stress markers allow for accurate assessment of the prognosis in patients with advanced heart failure ...
Anomalous right coronary artery originated from left coronary sinus with an interarterial course: subtypes and clinical ... Letter to the editor on article Anomalous origin of right coronary artery from left coronary sinus associated with aneurysm of ... Letter to the editor on article "Anomalous origin of right coronary artery from left coronary sinus associated with aneurysm of ... Anomalous origin of right coronary artery from left coronary sinus associated with aneurysm of aortic root. Heart, Vessels and ...
T1 - Novel post-processing image for the visualization of the coronary sinus by multidetector-row computed tomography before ... Novel post-processing image for the visualization of the coronary sinus by multidetector-row computed tomography before cardiac ... Novel post-processing image for the visualization of the coronary sinus by multidetector-row computed tomography before cardiac ... Novel post-processing image for the visualization of the coronary sinus by multidetector-row computed tomography before cardiac ...
b. Alcohol can induce coronary artery spasm and sinus tachycardia.. c. The author thinks that alcohol-inducing coronary artery ... Alcohol inhalation can be inducing coronary artery spasm and sinus tachycardia. Alcohol-inducing coronary artery spasm and ... a. It is recommended to widening the research in clearing the simultaneous presence of coronary artery spasm and sinus ... Indeed: the mechanism of alcohol-inducing coronary artery spasm and sinus tachycardia is unknown. Hypoxia is a suggested theory ...
N2 - Background: Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ... AB - Background: Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ... Background: Coronary sinus (CS) ostial atresia/abnormalities prevent access to the CS from the right atrium (RA) for left ... The combination of coronary sinus ostial atresia/abnormalities and a small persistent left superior vena cava-Opportunity for ...
Dive into the research topics of Anomalous origin of the right coronary artery from the left coronary sinus: Case report. ... Anomalous origin of the right coronary artery from the left coronary sinus: Case report. ...
Dive into the research topics of Double atrial potentials recorded in the coronary sinus in patients with Wolff-Parkinson- ... Double atrial potentials recorded in the coronary sinus in patients with Wolff-Parkinson-White syndrome: A possible mechanism ... Double atrial potentials recorded in the coronary sinus in patients with Wolff-Parkinson-White syndrome: A possible mechanism ... Double atrial potentials recorded in the coronary sinus in patients with Wolff-Parkinson-White syndrome: A possible mechanism ...
Anatomic proximity of the esophagus to the coronary sinus: Implication for catheter ablation within the coronary sinus. Journal ... Anatomic proximity of the esophagus to the coronary sinus : Implication for catheter ablation within the coronary sinus. In: ... Anatomic proximity of the esophagus to the coronary sinus: Implication for catheter ablation within the coronary sinus. / Tsao ... Anatomic proximity of the esophagus to the coronary sinus: Implication for catheter ablation within the coronary sinus. ...
Origin of the Right Coronary Artery from the left Sinus of Valsalva in a Donor Heart with Unsuccessful Repair.. William C ... a coronary angiogram was performed 3 years after the OHT and it showed anomalous origin of the right coronary artery (RCA) from ... As a consequence, an operation was performed to transfer the origin of the RCA to the right sinus of Valsalva. Unfortunately, ...
Minimally invasive direct coronary artery bypass-a surgical approach for anomalous right coronary artery from left aortic sinus ... Minimally invasive direct coronary artery bypass-a surgical approach for anomalous right coronary artery from left aortic sinus ... Minimally invasive direct coronary artery bypass-a surgical approach for anomalous right coronary artery from left aortic sinus ... Minimally invasive direct coronary artery bypass-a surgical approach for anomalous right coronary artery from left aortic sinus ...
Single Coronary Artery from Right Sinus of Valsalva: A Single Center Experience of Seven Cases. 2022 Lalani K Rao MS ... If a broken catheter tip can not be retrieved from the coronary artery, fix it! Coronary Artery Disease. 2022 Lalani K Shroff ... Simple and Complex Coronary Interventions (PCI), • Primary PCI for Acute Coronary Syndrome, • Imaging (IVUS/OCT) or Physiology ...
Anatomical Consideration and Potential Complications of Coronary Sinus Catheterisation. Mehra L, Raheja S, Agarwal S, Rani Y, ...
  • Kijima Y, Taniguchi M, Akagi T. Catheter closure of coronary sinus atrial septal defect using Amplatzer Septal Occluder. (medscape.com)
  • Figure 3 Coronary sinus subselective angiography by Attain Select™ sub-selection catheter. (wjgnet.com)
  • Coronary sinus pH measurement using a catheter mounted pH electrode is a validated sensitive technique for the detection of myocardial ischaemia. (bmj.com)
  • A catheter mounted hydrogen ion sensitive electrode was introduced into the coronary sinus and pH monitored continuously during dipyridamole infusion (0.56 mg/kg over four min). (bmj.com)
  • Conclusions: Here, we show for the first time that PICSO, a trans-coronary sinus catheter intervention, is associated with an increase in morphogens secreted into cardiac veins, normally present during cardiac development, and a significant induction of cell proliferation. (eur.nl)
  • Long-term electrode catheter pacing from coronary sinus. (bmj.com)
  • Contrast/ Dye studies aid in determining coronary sinus anatomy and catheter placement in the heart. (surgicalresearch.org)
  • The company said that proceeds from the financing round would be used primarily to commercialize its first product, the FDA-approved Coronary Sinus Access (CSA) System designed for vision-guided implantation of cardiac resynchronization therapy pacemakers to treat heart failure and to complete development of CardioOptics' therapeutic catheter ablation system to treat atrial fibrillation (AF). (bioworld.com)
  • Figure 2 Coronary sinus angiography, by Attain Command™ Delivery system. (wjgnet.com)
  • Single coronary artery is a coincidental finding during coronary angiography or at autopsy. (scirp.org)
  • Use of venous phase coronary angiography, a computed tomography scan with venous phase, or a left-sided upper extremity venogram may help reveal a variant anatomy and guide tool selection. (providence.org)
  • 6. Evaluation of Unroofed Coronary Sinus Syndrome Using Cardiovascular CT Angiography: An Observational Study. (nih.gov)
  • 14. CT angiography for diagnosis and subcategorization of unroofed coronary sinus syndrome. (nih.gov)
  • We studied 28 patients who underwent coronary angiography because of suspected coronary artery disease (CAD). (nih.gov)
  • Blood samples were obtained both from the aorta and the coronary sinus (CS) just before coronary angiography. (nih.gov)
  • We hypothesized that treatment with rivaroxaban, a factor Xa inhibitor, could reduce thrombin generation and improve outcomes for patients with worsening chronic heart failure and underlying coronary artery disease. (nih.gov)
  • RICHMOND, BC - Neovasc, the makers of a percutaneous treatment for refractory angina , announced today that the coronary sinus Reducer stent effectively reduced angina scores when compared with a sham procedure in patients with refractory angina [ 1 ] . (medscape.com)
  • We would like to report a case about percutaneous coronary intervention in a patient who has anomalous single coronary artery arising from right sinus valsalva. (scirp.org)
  • PiCSO is used as an adjunctive procedure after epicardial flow has been restored during the primary percutaneous coronary intervention (PCI) procedure. (newswire.co.kr)
  • citation needed] The coronary sinus is responsible for venous return of about 55% of the cardiac blood supply. (wikipedia.org)
  • Dilated coronary sinus is also seen in some congenital cardiovascular conditions, such as persistent left superior vena cava, and total anomalous pulmonary venous return. (wikipedia.org)
  • To test immediate molecular responses, in both patient groups, coronary venous blood samples were taken at baseline and after 20 min, the time required for the intervention. (eur.nl)
  • The unique mechanism of action, of intermittently occluding the coronary sinus outflow, redistributes venous blood-flow to the peri-infarct zone and enhances the coronary microcirculation viability by washing-out debris and other noxious agents of the infarct process. (newswire.co.kr)
  • 1. The value of cardiac CT in the diagnosis of unroofed coronary sinus syndrome. (nih.gov)
  • 2. Surgical management of unroofed coronary sinus syndrome: A 20-year-single-center experience. (nih.gov)
  • 3. Misdiagnosis of unroofed coronary sinus syndrome as an ostium primum atrial septal defect by echocardiography: A case report. (nih.gov)
  • 9. Unroofed coronary sinus syndrome: A case report. (nih.gov)
  • 10. Unroofed Coronary Sinus Syndrome: An Easily Corrected Congenital Anomaly But More Diagnostic Suspicion Is Needed. (nih.gov)
  • Long-Term Effect of Steroid Elution on the Electrical Performance of Coronary Sinus Leads for Cardiac Resynchronization Therapy. (medtronic.com)
  • Baljepally, R.M., Pollock, S.H. and Magram, M.Y. (1993) Transluminal angioplasty of a single coronary artery anomaly during acute myocardial infarction: A case report. (scirp.org)
  • 15. A hitherto unreported combination of pulmonary stenosis, single coronary artery anomaly, and coronary sinus to left atrial communication. (nih.gov)
  • Heart and Coronary Arteries: An Anatomical Atlas for Clinical Diagnosis, Radiological Investigation, and Surgical Treatment. (wikipedia.org)
  • Vilallonga, J.R. (2004) Anatomical variations in the coronary arteries. (scirp.org)
  • Conclusions: These findings confirm the proposed mechanism of sudden death and support early surgical repair of coronary arteries that course between the aortic root and the pulmonary trunk. (psu.edu)
  • Individuals with a bicuspid aortic valve (BAV) have long been noted to have clinically benign variations in coronary anatomy compared with the general population, including a higher prevalence of left coronary artery-dominant circulation, short left main coronary artery and separate ostia of the left anterior descending and circumflex coronary arteries. (bmj.com)
  • Less prevalent variations: Coronary anomalies. (scirp.org)
  • 2006) Coronary artery anomalies: Classification and ECG-gated multi-detector row CT findings with angiographic correlation. (scirp.org)
  • Yamanka, O. and Hobbs, R.E. (1990) Coronary ertery anomalies in 126,595 patients undergoing coronary arteriography. (scirp.org)
  • However, whether the prevalence of clinically significant coronary artery anomalies such as anomalous origin of a coronary artery from the opposite sinus (ACAOS) is higher in patients with BAV remains controversial. (bmj.com)
  • 8. Incidence and appearances of coronary sinus anomalies in adults on cardiac CT. (nih.gov)
  • The unique curve and braided core of the Worley Coronary Sinus Guide (CSG) helps you match your patient's anatomy to the length and curve of the CSG. (merit.com)
  • Results 2371 (years 1994-2015) and 1679 (years 2009-2015) consecutive patients with pathology-confirmed BAV and TAV, respectively, and defined preoperative coronary anatomy were identified. (bmj.com)
  • Understanding the differences in human and swine coronary sinus anatomy is crucial in preclinical safety studies, particularly for biodistribution evaluation. (surgicalresearch.org)
  • 4. Coronary sinus atrial septal defects in adults over the past 20 years at new Tokyo hospital: case series. (nih.gov)
  • 20. Totally endoscopic robotic repair of coronary sinus atrial septal defect. (nih.gov)
  • Some triglyceride-rich lipoproteins, including partially degraded very LDL levels, are believed to be independent risk factors for coronary artery disease. (medscape.com)
  • mean (SD) (range) age 49 (11) (31-62) years) with atypical pain and normal coronary angiograms were studied. (bmj.com)
  • CAD was defined as stenosis of more than 50% of the vessel diameter on coronary angiograms. (nih.gov)
  • It has been speculated that during exercise, compression of the coronary artery between the great vessels may impair coronary blood flow and produce myocardial ischemia and fatal arrhythmia. (psu.edu)
  • To this end, in a calf with an anomalous left coronary artery that coursed from the right sinus of Valsalva between the great vessels, we assessed for myocardial ischemia during pharmacologically induced tachycardia and hypertension. (psu.edu)
  • Methods: We identified a juvenile male calf (103 kg) with an anomalous left coronary artery from the right sinus of Valsalva that coursed between the great vessels. (psu.edu)
  • Left coronary artery resistance increased in a cardiac cycle-dependent pattern that was consistent with systolic compression between the great vessels. (psu.edu)
  • This helps doctors steer guidewires around sharp corners in hard-to-reach blood vessels during coronary procedures in the heart and other parts of the vascular system. (schmidtlaw.com)
  • Coronary heart disease is a narrowing of the small blood vessels that supply blood and oxygen to the heart. (stlukes-stl.com)
  • Angina is a type of chest discomfort or pain due to poor blood flow through the blood vessels (coronary vessels) of the heart muscle (myocardium). (stlukes-stl.com)
  • 2003) Primary coronary angio- plasty with stenting for acute coronary syndrome in patients with isolated single coronary artery. (scirp.org)
  • Overview of Acute Coronary Syndromes (ACS) Acute coronary syndromes result from acute obstruction of a coronary artery. (msdmanuals.com)
  • Papillary Muscle Disorders Numerous complications can occur as a result of an acute coronary syndrome and increase morbidity and mortality. (msdmanuals.com)
  • Mural Thrombosis Numerous complications can occur as a result of an acute coronary syndrome and increase morbidity and mortality. (msdmanuals.com)
  • Miracor Medical has developed the PiCSO Impulse System, the first and only coronary sinus intervention designed to reduce infarct size, improve cardiac function by clearing microcirculation and potentially reduce the onset of heart failure following acute myocardial infarction. (newswire.co.kr)
  • The role of myocardial ischaemia in the pathophysiology of the disease remains to be determined but coronary sinus pH monitoring provides a method for quantifying and prospectively assessing its effects on clinical presentation and prognosis. (bmj.com)
  • In this double-blind, randomized trial, 5022 patients who had chronic heart failure, a left ventricular ejection fraction of 40% or less, coronary artery disease, and elevated plasma concentrations of natriuretic peptides and who did not have atrial fibrillation were randomly assigned to receive rivaroxaban at a dose of 2.5 mg twice daily or placebo in addition to standard care after treatment for an episode of worsening heart failure. (nih.gov)
  • Angiographic studies demonstrate that a reduction of the LDL level in patients with coronary artery disease could cause slowing of progression, stabilization, or even regression of coronary artery lesions. (medscape.com)
  • Patients with established coronary disease and low HDL cholesterol levels are at high risk for recurrent events and should be targeted for aggressive nonpharmacological (ie, dietary modification, weight loss, physical exercise) and pharmacological treatment. (medscape.com)
  • Cardiovascular effects of rivaroxaban in heart failure patients with sinus rhythm and coronary disease with and without diabetes: a retrospective international cohort study from COMMANDER-HF. (bvsalud.org)
  • COMMANDER-HF was a randomised trial comparing rivaroxaban 2.5 mg two times a day to placebo, in addition to antiplatelet therapy , in patients hospitalised for worsening heart failure with coronary artery disease and sinus rhythm. (bvsalud.org)
  • This means it could be a potential alternative therapy for people with coronary heart disease and angina whose condition cannot be controlled. (dailymail.co.uk)
  • Coronary heart disease , high blood pressure, and aortic and mitral valve diseases may occur with sick sinus syndrome. (medlineplus.gov)
  • These effects mirror those associated with active smoking, with SHS exposure now causally linked with coronary heart disease, lung and nasal sinus cancer and associated with an increased risk of other cancers, stroke, chronic respiratory symptoms and adverse pregnancy outcomes ( California Environmental Protection Agency 2005 ). (nih.gov)
  • Coronary heart disease (CHD) is also cal. (stlukes-stl.com)
  • Infection hypertension, coronary artery disease, and noninsulin- dependent diabetes mellitus. (cdc.gov)
  • Coronary Sinus Lead Placement in Patients With Coronary Sinus Ostial A" by Ata Bajwa, Jashdeep Dhoot et al. (providence.org)
  • Coronary Sinus Lead Placement in Patients With Coronary Sinus Ostial Atresia: An Innovative Approach. (providence.org)
  • This case series demonstrates 2 innovative approaches to successful coronary sinus lead placement in the setting of coronary sinus ostial atresia. (providence.org)
  • That's the one that this system has been designed to significantly reduce the amount of procedure time" needed for lead placement in the coronary sinus. (bioworld.com)
  • AF was induced in 28 patients presenting in sinus rhythm via pacing or isoproterenol. (acc.org)
  • Holter or longer term rhythm monitors are effective tools for diagnosing sick sinus syndrome. (medlineplus.gov)
  • Sinus venosus ASD: Abnormal fusion between the embryologic sinus venosus and the atrium causes these defects. (medscape.com)
  • 19. [Coronary sinus defects: rare form of interatrial communication]. (nih.gov)
  • Pressure-controlled intermittent coronary sinus occlusion (PICSO), known to induce angiogenetic and vasoactive molecules as well as to reduce regional ischemia, may activate endogenous regenerative processes in failing myocardium. (eur.nl)
  • AWANS, BELGIUM--( Business Wire / Korea Newswire ) August 23, 2022 -- Miracor Medical SA (Miracor Medical) has announced the approval of an Investigational Device Exemption (IDE) from the FDA, enabling the company to initiate a pivotal study with its Pressure-controlled intermittent Coronary Sinus Occlusion (PiCSO) technology. (newswire.co.kr)
  • Prof. Mohl has worked and published about coronary sinus occlusion and interventions for decades, and invented the PiCSO therapy concept. (newswire.co.kr)
  • The Thebesian valve (TV) can be a significant obstacle to coronary sinus (CS) cannulation. (researchgate.net)
  • The coronary sinus receives blood mainly from the small, middle, great, and oblique cardiac veins. (wikipedia.org)
  • All veins that empty into the coronary sinus except for the oblique vein of the left atrium have valves at their junction with the coronary sinus. (wikipedia.org)
  • The anterior cardiac veins do not drain into the coronary sinus but drain directly into the right atrium. (wikipedia.org)
  • Catheters were advanced from the femoral veins to the right atrium, coronary sinus and transseptally to the left atrium. (acc.org)
  • Açar, G. , Fidan, S. , İzci, S. and Alizade, E. (2013) Coronary angioplasty for in-stent restenosis in patient with anomalous single coronary artery arising from right sinus valsalva. (scirp.org)
  • Objective To compare the prevalence and patterns of anomalous coronary artery origin from the opposite sinus (ACAOS) in patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV). (bmj.com)
  • Objective: An ectopic coronary artery that courses between the aortic root and the pulmonary trunk may lead to sudden cardiac death, especially in athletes. (psu.edu)
  • At the time of the intervention, the coronary sinus blood sample was taken and checked for the NPY levels. (cardiologynownews.org)
  • Sick sinus syndrome most often occurs in people older than age 50. (medlineplus.gov)
  • In children, heart surgery on the upper chambers is a common cause of sick sinus syndrome. (medlineplus.gov)
  • Sick sinus syndrome is uncommon, but not rare. (medlineplus.gov)
  • Sick sinus syndrome may cause symptoms of heart failure to start or get worse. (medlineplus.gov)
  • Sick sinus syndrome is diagnosed when the symptoms occur only during episodes of arrhythmia. (medlineplus.gov)
  • Holter monitoring is an effective tool for diagnosing sick sinus syndrome. (stlukes-stl.com)
  • A VVI (ventricular ventricu- lar inhibited) pacemaker had been implanted for treatment of sick sinus syndrome 9 years earlier. (cdc.gov)
  • Coronary sinus, normally located between the LEFT ATRIUM and LEFT VENTRICLE on the posterior surface of the heart, can serve as an anatomical reference for cardiac procedures. (nih.gov)
  • Early non-randomized European studies have suggested that this leads to reduced incidence of coronary microvascular obstruction (MVO) [3,4] and smaller infarct size, which are both strongly correlated to improvement in heart failure hospitalizations and reduced mortality following primary PCI [5]. (newswire.co.kr)
  • Persistent sinus tachycardia is usually ominous, often reflecting left ventricular failure and low cardiac output. (msdmanuals.com)
  • With treatment, the coronary sinus Reducer stent is implanted percutaneously into the coronary sinus and works by modulating the outflow of blood from the heart and to help redistribute flow to ischemic areas of the heart. (medscape.com)
  • Coronary Sinus Neuropeptide Y Levels and Adverse Outcomes in Patients With Stable Chronic Heart Failure. (ox.ac.uk)
  • Partially unroofed coronary sinus. (medscape.com)
  • Freedom RM, Culham JA, Rowe RD. Left atrial to coronary sinus fenestration (partially unroofed coronary sinus). (medscape.com)
  • 7. Transesophageal echocardiography for coronary sinus imaging in partially unroofed coronary sinus. (nih.gov)
  • 12. Partially unroofed coronary sinus: MDCT and MRI findings. (nih.gov)
  • Franz C, Mennicken U, Dalichau H, Hirsch H. Abnormal communication between the left atrium and the coronary sinus. (medscape.com)
  • Sinus Node Dysfunction Sinus node dysfunction refers to a number of conditions causing physiologically inappropriate atrial rates. (msdmanuals.com)
  • It passes across the backside of the heart along a groove between left atrium and left ventricle, then drains into the right atrium at the orifice of the coronary sinus (which is usually guarded by the valve of coronary sinus). (wikipedia.org)
  • citation needed] The coronary sinus drains through the posterior wall of right atrium at the orifice of the coronary sinus. (wikipedia.org)
  • 1992) Isolated single coronary artery: A review of 50,000 consecutive coronary artery angiographies. (scirp.org)
  • Sinus bradycardia occurs more often than the other types of the condition. (medlineplus.gov)
  • The implant reduces the rate of blood pumping out of the heart through a vein called the coronary sinus, one of the organ's main exit routes. (dailymail.co.uk)
  • As blood pumps out of the heart, it enters the coronary sinus vein and comes up against the steel implant, called the Neovasc Reducer. (dailymail.co.uk)
  • PiCSO-AMI-II will be the second major randomized trial to evaluate the role of PiCSO in improving coronary microvascular function and reducing infarct size in patients presenting with anterior STEMI. (newswire.co.kr)
  • The results of the study showed that NPY levels of coronary sinus were associated with prognostic implications in patients with heart failure. (cardiologynownews.org)
  • Attenhofer Jost CH, Connolly HM, Danielson GK, Dearani JA, Warnes CA, Jamil Tajik A. Clinical features and surgical outcome in 25 patients with fenestrations of the coronary sinus. (medscape.com)
  • Quaegebeur J, Kirklin JW, Pacifico AD, Bargeron LM Jr. Surgical experience with unroofed coronary sinus. (medscape.com)
  • 5. Coronary sinus septal defect (unroofed coronary sinus): echocardiographic diagnosis and surgical treatment. (nih.gov)
  • Investigation of Lipid level management using coronary UltraSound To assess Reduction of Atherosclerosis by CETP inhibition and HDL Elevation (ILLUSTRATE) was a randomized study that looked at the effect of torcetrapib in 1188 patients with CAD who underwent intravascular ultrasonography at baseline. (medscape.com)
  • This study suggests that IP-10 is a good surrogate marker of coronary atherosclerosis. (nih.gov)
  • 13. Efficacy of multidetector computed tomography for diagnosis of unroofed coronary sinus. (nih.gov)
  • Rare case of an unroofed coronary sinus: diagnosis by multidetector computed tomography. (nih.gov)
  • The coronary sinus arises upon the posterior aspect of the heart between the left atrium, and left ventricle. (wikipedia.org)
  • The coronary sinus commences at the union of the great cardiac vein, and the oblique vein of the left atrium. (wikipedia.org)
  • The sinus, before entering the right atrium, is considerably dilated - nearly to the size of the end of the little finger. (wikipedia.org)
  • citation needed] The orifice is usually guarded by the valve of coronary sinus (a thin, crescent-shaped valve located on the anteroinferior part of the opening into the right atrium). (wikipedia.org)
  • The coronary sinus connects directly with the right atrium. (wikipedia.org)
  • Atrial septal defect associated with drainage of left superior vena cava to left atrium and absence of the coronary sinus. (medscape.com)
  • In this rare type of ASD , part of the wall between the coronary sinus - which is part of the vein system of the heart - and the left upper heart chamber (left atrium) is missing. (middlesexhealth.org)
  • The coronary sinus runs transversely in the left atrioventricular groove (coronary sulcus) on the posterior aspect of the heart. (wikipedia.org)
  • ACAOS included right coronary artery from the left cusp, left circumflex artery from the right cusp and left main or left anterior descending artery from the right cusp. (bmj.com)
  • Candidates with coronary sinus or left ventricular pacing or defibrillation leads that are not likely to be entrapped by cerclage, evident on baseline CT or angiogram, are eligible to participate. (nih.gov)
  • All subjects underwent quantitative flow measurement in the coronary sinus by CMR at rest and during adenosine stress. (biomedcentral.com)
  • Cardiac therapies are often administered directly to the heart by methods such as coronary sinus retrograde infusion. (surgicalresearch.org)