Systole: Period of contraction of the HEART, especially of the HEART VENTRICLES.Myocytes, Cardiac: Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).Heart: The hollow, muscular organ that maintains the circulation of the blood.Cardiac Output: The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).Myocardial Contraction: Contractile activity of the MYOCARDIUM.Diastole: Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.Heart Ventricles: 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.Arrhythmias, Cardiac: 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.Cardiac Surgical Procedures: Surgery performed on the heart.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Death, Sudden, Cardiac: Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)Ventricular Function, Left: 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.Cardiac Volume: The volume of the HEART, usually relating to the volume of BLOOD contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is STROKE VOLUME.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Ventricular Function: The hemodynamic and electrophysiological action of the HEART VENTRICLES.Myocardium: 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.Cardiac Pacing, Artificial: Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.Heart Diseases: Pathological conditions involving the HEART including its structural and functional abnormalities.Mitral Valve: The valve between the left atrium and left ventricle of the heart.Electrocardiography: 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.Cardiomegaly: Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.Models, Cardiovascular: 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.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Stroke Volume: 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.Dogs: 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)Echocardiography, Doppler: 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.Kinetocardiography: The graphic recording of chest wall movement due to cardiac impulses.Cardiac Tamponade: Compression of the heart by accumulated fluid (PERICARDIAL EFFUSION) or blood (HEMOPERICARDIUM) in the PERICARDIUM surrounding the heart. The affected cardiac functions and CARDIAC OUTPUT can range from minimal to total hemodynamic collapse.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Cardiac-Gated Imaging Techniques: Timing the acquisition of imaging data to specific points in the cardiac cycle to minimize image blurring and other motion artifacts.Heart Failure: 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.Cardiomyopathies: 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).Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Ventricular Dysfunction, Left: 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.Heart Arrest: Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.Heart Function Tests: Examinations used to diagnose and treat heart conditions.Atrial Function, Left: The hemodynamic and electrophysiological action of the LEFT ATRIUM.Heart Auscultation: Act of listening for sounds within the heart.Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Fetal Heart: The heart of the fetus of any viviparous animal. It refers to the heart in the postembryonic period and is differentiated from the embryonic heart (HEART/embryology) only on the basis of time.Mitral Valve Insufficiency: 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.Mitral Valve Prolapse: Abnormal protrusion or billowing of one or both of the leaflets of MITRAL VALVE into the LEFT ATRIUM during SYSTOLE. This allows the backflow of blood into left atrium leading to MITRAL VALVE INSUFFICIENCY; SYSTOLIC MURMURS; or CARDIAC ARRHYTHMIA.Ventricular Remodeling: The geometric and structural changes that the HEART VENTRICLES undergo, usually following MYOCARDIAL INFARCTION. It comprises expansion of the infarct and dilatation of the healthy ventricle segments. While most prevalent in the left ventricle, it can also occur in the right ventricle.Ventricular Pressure: The pressure within a CARDIAC VENTRICLE. Ventricular pressure waveforms can be measured in the beating heart by catheterization or estimated using imaging techniques (e.g., DOPPLER ECHOCARDIOGRAPHY). The information is useful in evaluating the function of the MYOCARDIUM; CARDIAC VALVES; and PERICARDIUM, particularly with simultaneous measurement of other (e.g., aortic or atrial) pressures.Cardiomyopathy, Hypertrophic: A form of CARDIAC MUSCLE disease, characterized by left and/or right ventricular hypertrophy (HYPERTROPHY, LEFT VENTRICULAR; HYPERTROPHY, RIGHT VENTRICULAR), frequent asymmetrical involvement of the HEART SEPTUM, and normal or reduced left ventricular volume. Risk factors include HYPERTENSION; AORTIC STENOSIS; and gene MUTATION; (FAMILIAL HYPERTROPHIC CARDIOMYOPATHY).Myoblasts, Cardiac: Precursor cells destined to differentiate into cardiac myocytes (MYOCYTES, CARDIAC).Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Cardiac Myosins: Myosin type II isoforms found in cardiac muscle.Cardiac Imaging Techniques: Visualization of the heart structure and cardiac blood flow for diagnostic evaluation or to guide cardiac procedures via techniques including ENDOSCOPY (cardiac endoscopy, sometimes refered to as cardioscopy), RADIONUCLIDE IMAGING; MAGNETIC RESONANCE IMAGING; TOMOGRAPHY; or ULTRASONOGRAPHY.Pericardium: 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.Echocardiography, Doppler, Color: Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.Atrial Function: The hemodynamic and electrophysiological action of the HEART ATRIA.Cardiomyopathy, Dilated: 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.Echocardiography, Three-Dimensional: Echocardiography amplified by the addition of depth to the conventional two-dimensional ECHOCARDIOGRAPHY visualizing only the length and width of the heart. Three-dimensional ultrasound imaging was first described in 1961 but its application to echocardiography did not take place until 1974. (Mayo Clin Proc 1993;68:221-40)Cardiac Glycosides: Cyclopentanophenanthrenes with a 5- or 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. Plants they come from have long been used in congestive heart failure. They increase the force of cardiac contraction without significantly affecting other parameters, but are very toxic at larger doses. Their mechanism of action usually involves inhibition of the NA(+)-K(+)-EXCHANGING ATPASE and they are often used in cell biological studies for that purpose.Ventricular Function, Right: The hemodynamic and electrophysiological action of the right HEART VENTRICLE.Heart Conduction System: 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.Myocardial Ischemia: 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).Heart Sounds: The sounds heard over the cardiac region produced by the functioning of the heart. There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is heard as a "lubb" sound; the second is produced by the closing of the AORTIC VALVE and PULMONARY VALVE and is heard as a "dupp" sound; the third is produced by vibrations of the ventricular walls when suddenly distended by the rush of blood from the HEART ATRIA; and the fourth is produced by atrial contraction and ventricular filling.Cardiac Output, Low: A state of subnormal or depressed cardiac output at rest or during stress. It is a characteristic of CARDIOVASCULAR DISEASES, including congenital, valvular, rheumatic, hypertensive, coronary, and cardiomyopathic. The serious form of low cardiac output is characterized by marked reduction in STROKE VOLUME, and systemic vasoconstriction resulting in cold, pale, and sometimes cyanotic extremities.Echocardiography, Doppler, Pulsed: Echocardiography applying the Doppler effect, with velocity detection combined with range discrimination. Short bursts of ultrasound are transmitted at regular intervals and the echoes are demodulated as they return.Out-of-Hospital Cardiac Arrest: Occurrence of heart arrest in an individual when there is no immediate access to medical personnel or equipment.Heart Septum: This structure includes the thin muscular atrial septum between the two HEART ATRIA, and the thick muscular ventricular septum between the two HEART VENTRICLES.Cardiotonic Agents: Agents that have a strengthening effect on the heart or that can increase cardiac output. They may be CARDIAC GLYCOSIDES; SYMPATHOMIMETICS; or other drugs. They are used after MYOCARDIAL INFARCT; CARDIAC SURGICAL PROCEDURES; in SHOCK; or in congestive heart failure (HEART FAILURE).Magnetic Resonance Imaging, Cine: A type of imaging technique used primarily in the field of cardiology. By coordinating the fast gradient-echo MRI sequence with retrospective ECG-gating, numerous short time frames evenly spaced in the cardiac cycle are produced. These images are laced together in a cinematic display so that wall motion of the ventricles, valve motion, and blood flow patterns in the heart and great vessels can be visualized.Prospective Studies: 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.Heart Transplantation: The transference of a heart from one human or animal to another.Torsion, Mechanical: A twisting deformation of a solid body about an axis. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Troponin I: One of the three polypeptide chains that make up the TROPONIN complex. It inhibits F-actin-myosin interactions.Pulse: The rhythmical expansion and contraction of an ARTERY produced by waves of pressure caused by the ejection of BLOOD from the left ventricle of the HEART as it contracts.Coronary Vessels: The veins and arteries of the HEART.Papillary Muscles: Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.Hypertrophy, Left Ventricular: Enlargement of the LEFT VENTRICLE of the heart. This increase in ventricular mass is attributed to sustained abnormal pressure or volume loads and is a contributor to cardiovascular morbidity and mortality.Heart Block: 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.Endocardium: The innermost layer of the heart, comprised of endothelial cells.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Heart Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.Pacemaker, Artificial: A device designed to stimulate, by electric impulses, contraction of the heart muscles. It may be temporary (external) or permanent (internal or internal-external).Reproducibility of Results: 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.Heart Murmurs: Heart sounds caused by vibrations resulting from the flow of blood through the heart. Heart murmurs can be examined by HEART AUSCULTATION, and analyzed by their intensity (6 grades), duration, timing (systolic, diastolic, or continuous), location, transmission, and quality (musical, vibratory, blowing, etc).Tricuspid Valve: The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.Treatment Outcome: 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.Aortic Valve: The valve between the left ventricle and the ascending aorta which prevents backflow into the left ventricle.Cardiac Resynchronization Therapy: The restoration of the sequential order of contraction and relaxation of the HEART ATRIA and HEART VENTRICLES by atrio-biventricular pacing.Pulsatile Flow: Rhythmic, intermittent propagation of a fluid through a BLOOD VESSEL or piping system, in contrast to constant, smooth propagation, which produces laminar flow.Troponin T: One of the three polypeptide chains that make up the TROPONIN complex. It is a cardiac-specific protein that binds to TROPOMYOSIN. It is released from damaged or injured heart muscle cells (MYOCYTES, CARDIAC). Defects in the gene encoding troponin T result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.Predictive Value of Tests: 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.Isoproterenol: Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.Elasticity: Resistance and recovery from distortion of shape.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Cardiopulmonary Resuscitation: The artificial substitution of heart and lung action as indicated for HEART ARREST resulting from electric shock, DROWNING, respiratory arrest, or other causes. The two major components of cardiopulmonary resuscitation are artificial ventilation (RESPIRATION, ARTIFICIAL) and closed-chest CARDIAC MASSAGE.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Heart Neoplasms: Tumors in any part of the heart. They include primary cardiac tumors and metastatic tumors to the heart. Their interference with normal cardiac functions can cause a wide variety of symptoms including HEART FAILURE; CARDIAC ARRHYTHMIAS; or EMBOLISM.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Cardiac Care Facilities: Institutions specializing in the care of patients with heart disorders.Cineangiography: Motion pictures of the passage of contrast medium through blood vessels.Myocardial Bridging: A malformation that is characterized by a muscle bridge over a segment of the CORONARY ARTERIES. Systolic contractions of the muscle bridge can lead to narrowing of coronary artery; coronary compression; MYOCARDIAL ISCHEMIA; MYOCARDIAL INFARCTION; and SUDDEN CARDIAC DEATH.Ductus Arteriosus: A fetal blood vessel connecting the pulmonary artery with the descending aorta.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Echocardiography, Transesophageal: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.Cardiac Electrophysiology: The study of the electrical activity and characteristics of the HEART; MYOCARDIUM; and CARDIOMYOCYTES.Vascular Resistance: 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.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Pulmonary Circulation: The circulation of the BLOOD through the LUNGS.Coronary Disease: 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.Aorta: The main trunk of the systemic arteries.Fibrosis: Any pathological condition where fibrous connective tissue invades any organ, usually as a consequence of inflammation or other injury.Dobutamine: A catecholamine derivative with specificity for BETA-1 ADRENERGIC RECEPTORS. It is commonly used as a cardiotonic agent after CARDIAC SURGERY and during DOBUTAMINE STRESS ECHOCARDIOGRAPHY.Observer Variation: The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Aortic Valve Stenosis: A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Follow-Up Studies: 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.Retrospective Studies: 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.Pulmonary Artery: The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs.Tricuspid Valve Insufficiency: Backflow of blood from the RIGHT VENTRICLE into the RIGHT ATRIUM due to imperfect closure of the TRICUSPID VALVE.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Heart Injuries: General or unspecified injuries to the heart.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Sensitivity and Specificity: 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)Imaging, Three-Dimensional: 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.Blood Volume: Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.Image Interpretation, Computer-Assisted: Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.Organ Size: The measurement of an organ in volume, mass, or heaviness.Heart Valve Prosthesis: A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.Cardiopulmonary Bypass: 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.Oxygen Consumption: 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)Hypertension: Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Troponin: One of the minor protein components of skeletal muscle. Its function is to serve as the calcium-binding component in the troponin-tropomyosin B-actin-myosin complex by conferring calcium sensitivity to the cross-linked actin and myosin filaments.Amyl Nitrite: A vasodilator that is administered by inhalation. It is also used recreationally due to its supposed ability to induce euphoria and act as an aphrodisiac.Ultrasonography, Prenatal: The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the fetus and with reference to organs or the detection of maternal or fetal disease.Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Myocarditis: Inflammatory processes of the muscular walls of the heart (MYOCARDIUM) which result in injury to the cardiac muscle cells (MYOCYTES, CARDIAC). Manifestations range from subclinical to sudden death (DEATH, SUDDEN). Myocarditis in association with cardiac dysfunction is classified as inflammatory CARDIOMYOPATHY usually caused by INFECTION, autoimmune diseases, or responses to toxic substances. Myocarditis is also a common cause of DILATED CARDIOMYOPATHY and other cardiomyopathies.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Doppler Effect: Changes in the observed frequency of waves (as sound, light, or radio waves) due to the relative motion of source and observer. The effect was named for the 19th century Austrian physicist Johann Christian Doppler.Sarcomeres: The repeating contractile units of the MYOFIBRIL, delimited by Z bands along its length.Atrial Natriuretic Factor: A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.Muscle Proteins: The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.Mitral Valve Stenosis: Narrowing of the passage through the MITRAL VALVE due to FIBROSIS, and CALCINOSIS in the leaflets and chordal areas. This elevates the left atrial pressure which, in turn, raises pulmonary venous and capillary pressure leading to bouts of DYSPNEA and TACHYCARDIA during physical exertion. RHEUMATIC FEVER is its primary cause.Ultrasonography, Doppler: Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)Risk Factors: 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.Swine: 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).Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Mitochondria, Heart: The mitochondria of the myocardium.Heart Valves: Flaps of tissue that prevent regurgitation of BLOOD from the HEART VENTRICLES to the HEART ATRIA or from the PULMONARY ARTERIES or AORTA to the ventricles.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Elasticity Imaging Techniques: Non-invasive imaging methods based on the mechanical response of an object to a vibrational or impulsive force. It is used for determining the viscoelastic properties of tissue, and thereby differentiating soft from hard inclusions in tissue such as microcalcifications, and some cancer lesions. Most techniques use ultrasound to create the images - eliciting the response with an ultrasonic radiation force and/or recording displacements of the tissue by Doppler ultrasonography.Edema, Cardiac: Abnormal fluid retention by the body due to impaired cardiac function or heart failure. It is usually characterized by increase in venous and capillary pressure, and swollen legs when standing. It is different from the generalized edema caused by renal dysfunction (NEPHROTIC SYNDROME).Tetralogy of Fallot: A combination of congenital heart defects consisting of four key features including VENTRICULAR SEPTAL DEFECTS; PULMONARY STENOSIS; RIGHT VENTRICULAR HYPERTROPHY; and a dextro-positioned AORTA. In this condition, blood from both ventricles (oxygen-rich and oxygen-poor) is pumped into the body often causing CYANOSIS.Pulmonary Veins: The veins that return the oxygenated blood from the lungs to the left atrium of the heart.Image Enhancement: Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level.Biological Markers: 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.Rheology: The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.Mice, Inbred C57BLSignal Processing, Computer-Assisted: Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.Contrast Media: Substances used to allow enhanced visualization of tissues.Postoperative Complications: 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.Ventricular Fibrillation: A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.Counterpulsation: A technique for assisting the circulation by decreasing the afterload of the left ventricle and augmenting the diastolic pressure. It may be achieved by intra-aortic balloon, or by implanting a special pumping device in the chest, or externally by applying a negative pressure to the lower extremities during cardiac systole.Animals, Newborn: Refers to animals in the period of time just after birth.Natriuretic Peptide, Brain: A PEPTIDE that is secreted by the BRAIN and the HEART ATRIA, stored mainly in cardiac ventricular MYOCARDIUM. It can cause NATRIURESIS; DIURESIS; VASODILATION; and inhibits secretion of RENIN and ALDOSTERONE. It improves heart function. It contains 32 AMINO ACIDS.Myocardial Reperfusion Injury: 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.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Mitral Valve Annuloplasty: 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.Aortic Valve Insufficiency: Pathological condition characterized by the backflow of blood from the ASCENDING AORTA back into the LEFT VENTRICLE, leading to regurgitation. It is caused by diseases of the AORTIC VALVE or its surrounding tissue (aortic root).Aging: The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.Risk Assessment: 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)Coronary Artery Bypass: 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.Sarcolemma: The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Myosin Heavy Chains: The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS. The heavy chains possess actin-binding and ATPase activity.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Arteries: The vessels carrying blood away from the heart.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Thermodilution: Measurement of blood flow based on induction at one point of the circulation of a known change in the intravascular heat content of flowing blood and detection of the resultant change in temperature at a point downstream.Coronary Stenosis: Narrowing or constriction of a coronary artery.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.GATA4 Transcription Factor: A GATA transcription factor that is expressed in the MYOCARDIUM of developing heart and has been implicated in the differentiation of CARDIAC MYOCYTES. GATA4 is activated by PHOSPHORYLATION and regulates transcription of cardiac-specific genes.Gestational Age: The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Ventricular Dysfunction: A condition in which HEART VENTRICLES exhibit impaired function.Thoracic Surgery: A surgical specialty concerned with diagnosis and treatment of disorders of the heart, lungs, and esophagus. Two major types of thoracic surgery are classified as pulmonary and cardiovascular.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Pericardial Effusion: Fluid accumulation within the PERICARDIUM. Serous effusions are associated with pericardial diseases. Hemopericardium is associated with trauma. Lipid-containing effusion (chylopericardium) results from leakage of THORACIC DUCT. Severe cases can lead to CARDIAC TAMPONADE.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.NAV1.5 Voltage-Gated Sodium Channel: A voltage-gated sodium channel subtype that mediates the sodium ion PERMEABILITY of CARDIOMYOCYTES. Defects in the SCN5A gene, which codes for the alpha subunit of this sodium channel, are associated with a variety of CARDIAC DISEASES that result from loss of sodium channel function.Endomyocardial Fibrosis: A condition characterized by the thickening of the ventricular ENDOCARDIUM and subendocardium (MYOCARDIUM), seen mostly in children and young adults in the TROPICAL CLIMATE. The fibrous tissue extends from the apex toward and often involves the HEART VALVES causing restrictive blood flow into the respective ventricles (CARDIOMYOPATHY, RESTRICTIVE).Prognosis: 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.Adrenergic beta-Antagonists: 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.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Exercise Test: 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.Autonomic Nervous System: The ENTERIC NERVOUS SYSTEM; PARASYMPATHETIC NERVOUS SYSTEM; and SYMPATHETIC NERVOUS SYSTEM taken together. Generally speaking, the autonomic nervous system regulates the internal environment during both peaceful activity and physical or emotional stress. Autonomic activity is controlled and integrated by the CENTRAL NERVOUS SYSTEM, especially the HYPOTHALAMUS and the SOLITARY NUCLEUS, which receive information relayed from VISCERAL AFFERENTS.
Ventricular systole Cardiac diastole ECG The EKG complex. P=P wave, PR=PR interval, QRS=QRS complex, QT=QT interval, ST=ST ... Carl J. Wiggers, is a standard diagram that is used in teaching cardiac physiology. In the Wiggers diagram, the X-axis is used ... assisting one in understanding the entire cardiac cycle. Note that during isovolumetric/isovolumic contraction and relaxation, ...
Vesalius believed that cardiac systole is synchronous with the arterial pulse. He not only verified Estienne's findings on the ...
The heart is innervated by a cardiac ganglion. Myofibrils are mostly arranged circularly and constrict the heart during systole ...
Elevating Ca2+ concentration to a high enough level results in cardiac arrest in systole. This unfortunate irreversible event ... Cardioplegia is intentional and temporary cessation of cardiac activity, primarily for cardiac surgery. The word cardioplegia ... Hensley F, Martin D. A Practical Approach to Cardiac Anesthesia. 2nd Edition. Little, Brown and Company. 1995 Berne R, Levy M. ... This is achieved by reducing myocardial metabolism through a reduction in cardiac work load and by the use of hypothermia. ...
Back flow of blood through its opening during atrial systole is prevented by the Thebesian valve. The smallest cardiac veins ... Cardiology Vital heat Cardiac muscle Major systems of the human body Amato Lusitano Vascular resistance "circulatory system" at ... The renal circulation receives around 20% of the cardiac output. It branches from the abdominal aorta and returns blood to the ... The evolutionary origin of cardiac chambers. Dev. Biol. 277: 1-15. "Crocodilian Hearts". National Center for Science Education ...
The latissimus dorsi is occasionally used for transplantation, and for augmentation of systole in cardiac failure. In these ...
Volumetric definition of the heart in systole was first described by Adolph Fick as cardiac output. Fick may be readily and ... Diastole is the cardiac cycle phase during which the heart is relaxing and filling with incoming blood that is being returned ... As a consequence, cardiac output becomes diminished. When the left ventricular diastolic pressure is elevated, venous pressure ... During diastole, the ventricular pressure falls from the peak reached at the end of systole. When this pressure falls below the ...
Doctors take a cardiac MRI to determine extent and location of the damage. Occasionally this reveals that the patient may be ... Fick/Frank/Starling describes gas diffusion, fluid and compliance relationships of the myocardium, primarily in systole. ... The Dor procedure is a medical technique used as part of heart surgery and originally introduced by the French cardiac surgeon ... There is a 4% chance the patient will require another cardiac operation: 18% of patients who underwent CABG had recurrent heart ...
Cardiac Surgery Department, Regional Cardiac Center, Morriston Hospital, Swansea, UK, Ital Heart J 2005; 6 (4): 361-362). ... That is, it actively deflates in systole, increasing forward blood flow by reducing afterload through a vacuum effect. It ... Increasing cardiac output increases coronary blood flow and therefore myocardial oxygen delivery. It consists of a cylindrical ... is a mechanical device that increases myocardial oxygen perfusion while at the same time increasing cardiac output. ...
The mitral annulus changes in shape and size during the cardiac cycle. It is smaller at the end of atrial systole due to the ... This reduction in annulus size at the end of atrial systole may be important for the proper coapting of the leaflets of the ... The late filling of the left ventricle contributes about 20% to the volume in the left ventricle prior to ventricular systole, ... The mitral annulus is saddle shaped and changes in shape throughout the cardiac cycle. The annulus contracts and reduces its ...
... is that part of the cardiac cycle during which the heart refills with blood after the emptying done during systole (contraction ... thus a reduced cardiac output. Over time, decreased cardiac output will diminish the ability of the heart to circulate blood ... For a healthy human heart the entire cardiac cycle typically runs less than one second. That is, for a normal heart rate of 72 ... The atrial kick does not supply the larger amount of flow (during the cardiac cycle) as about 80 per cent of the collected ...
During systole, a ventricle with subepicardial ischemia will exhibit cells with higher amplitude of depolarization in the ... Left ventricular aneurysm Blunt trauma to the chest resulting in a cardiac contusion Hyperkalemia Acute myocarditis Pulmonary ... generating a vector that points towards the normal cardiac cells (which have positive charges on their surface). This vector ... cardiac endocardium. During transmural ischemia, the Na+/K+ATPase which is responsible for the final stages of myocyte ...
There are several causes of sudden cardiac death and it is distinct from cardiac arrest. The leading cause of SCD in young ... It pulsates opposite to the heart such that it inflates during diastole and relaxes during systole. Deflation during systole ... Treatment of cardiac arrest includes cardiopulmonary resuscitation (CPR), defibrillation, and advanced cardiac life support ( ... Troponin - The troponin complex is present in skeletal and cardiac muscle, but cardiac-specific forms of troponin I and ...
It may be due to low cardiac output (as seen in shock, congestive cardiac failure), hypovolemia, valvular heart disease (such ... Pulsatile This description of the pulse implies the intrinsic physiology of systole and diastole. Scientifically, systole and ... It is caused by an exaggerated decrease in blood pressure during this phase, and is diagnostic of a variety of cardiac and ... This pulse signals a flagging effort of the heart to sustain itself in systole. Pulsus bigeminus: indicates a pair of hoofbeats ...
... occurs in the time phase of cardiac systole, whereas vasoconstriction follows in the opposite time phase of ... Cardiac output (blood flow measured in volume per unit time) is computed by multiplying the heart rate (in beats per minute) ... An increase in either of these physiological components (cardiac output or TPR) causes a rise in the mean arterial pressure. ... Vasodilation directly affects the relationship between mean arterial pressure, cardiac output, and total peripheral resistance ...
Heart Rate Cardiac output is dependent on stroke volume and heart rate. A significant portion (55-77%) of HFpEF patients are ... This is termed partial persistent systole. Ischemia may manifest in distinct ways, either as a result of increasing tissue ... The benefit patients seem to derive from exercise does not seem to be a direct cardiac effect but rather is due to changes in ... HFpEF and Aging Cardiac senescence, or cellular deterioration that occurs as part of normal aging, closely resembles the ...
Diastole is an - active expansion of the muscle on which the cardiac return depends. This is an addition to Starling's law of ... was made approximately 500 years after Sir William Harvey's discovery of the mechanical function of Ventricular Systole. This ... its rhythmical opening and closing during each cardiac beat. This new information on venous valves comes almost 500 years after ...
... from the sternum at which the cardiac impulse can be felt. The cardiac impulse is the vibration resulting from the heart ... rotating, moving forward and striking against the chest wall during systole. The PMI is not the apex of the heart but is on the ...
... leading to an increase in Ca2+ release into the cytosol during systole. Therefore, minimizing cardiac myostatin may improve ... Pathological states that increase cardiac stress and promote heart failure can induce a rise in both cardiac myostatin mRNA and ... in which cardiac myostatin induces whole-body muscular atrophy. Physiologically, minimal amounts of cardiac myostatin are ... A reduction in cardiac myostatin induces eccentric hypertrophy of the heart, and increases its sensitivity to beta-adrenergic ...
... it may lead to cardiac tamponade, which can be deadly if not treated promptly. One study found that cardiac tamponade was fatal ... Early signs of this compression include right atrial inversion during ventricular systole followed by diastolic compression of ... This compression, called cardiac tamponade, is often associated with hemopericardium and can be fatal if not diagnosed and ... Hong, Yu-Cheng; Chen, Yi-Guan; Hsiao, Cheng-Ting; Kuan, Jen-tse; Chiu, Te-Fa; Chen, Jih-Chang (2007). "Cardiac tamponade ...
The cardiac output is normalized to body size through body surface area and is called the cardiac index. The average cardiac ... Afterload, or how much pressure the heart must generate to eject blood at systole, is influenced by vascular resistance. It can ... the middle cardiac vein (draining the bottom of the left and right ventricles), and small cardiac veins. The anterior cardiac ... and Cardiac Electrophysiology: Journal of the Working Groups on Cardiac Pacing, Arrhythmias, and Cardiac Cellular ...
In cardiac physiology, isovolumetric contraction is an event occurring in early systole during which the ventricles contract ... Isovolumetric relaxation Cardiac cycle Blood pressure Wiggers diagram Pocock, J., and Richards, C.D. (2006). Human Physiology, ... with no corresponding volume change (isovolumetrically). This short-lasting portion of the cardiac cycle takes place whilst all ...
... increases the binding efficiency of cardiac troponin in the myofibril to the calcium ions that are already present in systole. ...
Similar to cardiac index, is a method of relating the stroke volume (SV) to the size of the person Body surface area (BSA). S V ... Elevated afterload (commonly measured as the aortic pressure during systole) reduces stroke volume. Though not usually ... Stroke volume is an important determinant of cardiac output, which is the product of stroke volume and heart rate, and is also ... Because stroke volume increase in certain conditions and disease states, stroke volume itself correlates with cardiac function ...
For heart patients with low cardiac output and who are not candidates for cardiac transplantation, a procedure called ... wrapping the latissimus dorsi muscles around the heart and electrostimulating them in synchrony with ventricular systole. ...
... cardiac involuntary muscles.[68] The main structures of the heart are the sinus venosus, the pacemaker, the left atrium, the ... a muscular ridge that subdivides the ventricle during ventricular diastole and completely divides it during ventricular systole ...
Location in the Cardiac Cycle--Determining when the heart murmur occurs during the cycle can help determine where in the heart ... Pathological murmurs typically occupy all of systole or diastole.. Shape--This refers to the pattern of intensity change over ... In older horses which are not suffering from some other disease, murmurs of grade three or higher often relate to cardiac ... During one study, the ability to diagnose the underlying cardiac problem causing abnormal heart sounds was only 54%, 33%, and ...
Heart rhythm disorders roots- palpitations and Wobbly spells to sudden a systole. Cardiac rhythm management devices are ... Cardiac Rhythm Management Devices are the devices which are made to prevent the unfortunate events with the cardiac patients. ... Prevalence of cardiac related patients and diseases are some factors driving the market of cardiac Rhythm Management devices ... 3. Chapter - Global Cardiac Rhythm Management Devices Market Overview: Quantitative Analysis 4. Chapter - Global Cardiac Rhythm ...
Cardiac auscultation is performed systematically over five locations on the anterior chest wall. Use the stethoscopes ... Heart murmur duration refers to the portion of systole or diastole that the murmur occupies. Terms used include short and long ... Our lessons often describe heart murmur timing within a cardiac cycle. Systolic murmurs occur between the first heart sound (S1 ... In addition, timing is used to describe when murmurs occur within systole or diastole. For example, early systolic, mid- ...
The patients systole and diastole of the heart is measured by placing three ECG stickers on the patients chest. ... A cardiac rehabilitation exercise program that is supervised by professional is beneficial for the patient. - The patients ...
Figure 9: The detection at the end-expiration. The blue circle denotes the end-expiration. Frames (A) and (B) are the first frame and last frame in the end-expiration ...
Systole and Diastole - Cardiac Cycle & boost your knowledge! Study for your classes, USMLE, MCAT or MBBS. Learn online with ... This article covers the aspects of cardiac physiology that are relevant in medical exams and creates a basic understanding of ...
... for left ventricular strain measurement during the systole using cine-gated... ... A new tool to assess regional inhomogeneity in cardiac function. Basic Research in Cardiology 96(6), 595-605 (2001)CrossRef ... The Hyperelastic Warping solution was evolved using a series of non-tagged images in 10 phases from end-diastole to end-systole ... Guccione, J.M., McCulloch, A.D.: Mechanics of active contraction in cardiac muscle: Part I-constitutive relations for fiber ...
Here, we discuss the difference between diastole and systole and the risks of hypertension (high) and hypotension (low) blood ... Diastole and systole are two phases of the cardiac cycle. They occur as the heart beats, pumping blood through a system of ... What are diastole and systole?. Diastole is when the heart muscle relaxes and systole is when the heart muscle contracts. ... The terms diastole and systole refer to when the heart muscles relax and contract. The balance between diastole and systole ...
Cardiac Cycle - Systole & Diastole. Uploaded by Tracy Rivera on October 5, 2014 at 12:27 am ... Thanks to McGraw Hill you can watch this video of the cardiac cycle! ...
and the cardiac cycle well be discussing in two fashions, and one way we will discussing cardiac cycle while I will be doing ... now, today well be talking about the cardiac cycle. ... Determinants of Cardiac Output - Part 2 of 3 * How do blood ... When I will be presenting the errands during the cardiac cycle Graphically So first of all, ... different diagrams and in second phase, Well discuss the cardiac cycle Uhhhhh, ...
... ventricular systole, and relaxation.. *Atrial systole: During the atrial systole phase of the cardiac cycle, the atria contract ... Systole. During systole, cardiac muscle tissue is contracting to push blood out of the chamber. ... Cardiac Output. Cardiac output (CO) is the volume of blood being pumped by the heart in one minute. The equation used to find ... The Cardiac Cycle. The cardiac cycle includes all of the events that take place during one heartbeat. There are 3 phases to the ...
systole answers are found in the Tabers Medical Dictionary powered by Unbound Medicine. Available for iPhone, iPad, Android, ... In the cardiac cycle, atrial systole precedes ventricular systole, which pumps blood into the aorta and pulmonary artery. ... In the cardiac cycle, atrial systole precedes ventricular systole, which pumps blood into the aorta and pulmonary artery. ... SEE: cardiac cycle; SEE: diastole; SEE: murmur; SEE: presystole. Theres more to see -- the rest of this entry is available ...
... it will recoil elastically during systole and potentially may influence the overall shortening behavior of cardiac muscle [22]. ... Gene context of Systole. *LV wall thickness during systole and % fractional shortening were diminished by 8-10% in Cx43- ... Energy levels at systole vs. diastole in normal hamster hearts vs. myopathic hamster hearts. Sievers, R., Parmley, W.W., James ... Cardiac structure and function in young and senescent mice heterozygous for a connexin43 null mutation. Betsuyaku, T., Kovacs, ...
Ventricular systole Cardiac diastole ECG The EKG complex. P=P wave, PR=PR interval, QRS=QRS complex, QT=QT interval, ST=ST ... Carl J. Wiggers, is a standard diagram that is used in teaching cardiac physiology. In the Wiggers diagram, the X-axis is used ... assisting one in understanding the entire cardiac cycle. Note that during isovolumetric/isovolumic contraction and relaxation, ...
Cardiac systole and diastole. During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum ( ... MAP is the average of blood pressure over a cardiac cycle and is determined by the cardiac output (CO), systemic vascular ... Cardiac output is the product of stroke volume and heart rate, and stroke volume is influenced by blood volume. In the short- ... The resultant increase in blood volume results in an increased cardiac output by the Frank-Starling law of the heart, in turn ...
Our aim was to determine the diagnostic value of myocardial tagging sequences with regard to the evaluable share of the cardiac ... systole could be assessed in 69% of patients, and an evaluation of the whole cardiac cycle was not possible. With the SSFP ... Schar M, Kozerke S, Fischer SE, Boesiger P (2004) Cardiac SSFP imaging at 3 Tesla. Magn Reson Med 51:799-806PubMedCrossRef ... Strach K, Meyer C, Schild H, Sommer T (2006) Cardiac stress MR imaging with dobutamine. Eur Radiol 16:2728-2738PubMedCrossRef ...
In order to diagnose a possible cardiac disorder, ECG (electrocardiogram) signals are usually recorded on standard grid papers ... Systole: Contracting or pumping phase of a cardiac chamber.. Electrocardiogram: Electrical activity of the heart is recorded in ... Diastole: Relaxing or filling phase of a cardiac chamber.. Histogram: Histogram of an image plots the number of pixels for each ... In order to diagnose a possible cardiac disorder, ECG (electrocardiogram) signals are usually recorded on standard grid papers ...
Systole. Ejection. Cardiac. Stroke. Pump. Minute. Rate. Systole. Diastole. Pressure. 02. Volume. Volume. Fraction. Output. Work ... Nowadays, CHF is considered as the fastest-growing clinical cardiac disease entity in the United States, affecting 2% of the ... VADs need to be clearly distinguished from artificial hearts, which are designed to completely take over cardiac function and ... Epi-cardial electrode with an incorporated cardiac radio-frequency receiver (C&R) for temporary heart stimulation from the ...
These two phases are commonly understood as systole and diastole. The rest phase is considered polarized. The resting potential ... Cardiac muscle cells or cardiomyocytes (also known as myocardiocytes or cardiac myocytes) are the muscle cells (myocytes) that ... Cardiac pacemaker cells carry the impulses that are responsible for the beating of the heart. They are distributed throughout ... "The Cardiac Muscle Cell" (PDF). Archived from the original (PDF) on 2016-03-09. Retrieved 2012. Check date values in: ,access- ...
We found a significant contribution of synchronized atrial contraction; cardiac output increased 27% when pacing mode was ... We therefore investigated the extent by which synchronized atrioventricular contraction contributes to cardiac output and ... Contribution of Synchronized Atrial Systole to Left Ventricular Contraction in the Newborn Pig Heart. ... cardiac work in a neonatal circulation, and whether this effect can be fully explained by the Starling mechanism. In neonatal ...
This is called systole.• When the cardiac muscle relaxes, pressure within the heart decreases. This allows blood to flow into ... The cardiac cycle includes all the events that take place as the blood flows through the heart during one complete heartbeat.• ... This results in an increase in the cardiac rate so that carbon dioxide-rich blood is taken quickly to the lungs to be ... The increased blood causes the SA node to be stimulated, thus increasing the cardiac rate. The blood is able to be pumped out ...
Stages of the cardiac cycle is divided into five steps: [31] *Atrial Systole:Mitral valve opens rapidly and semilunar valves is ... Cardiac Pump Function[edit]. Cardiac Cycle[edit]. Cardiac events occurring in the cardiac cycle. Two complete cycles are ... Cardiac Output[edit]. Cardiac output (Q or Q. ˙. c. {\displaystyle {\dot {Q}}_{c}}. or CO ) is the amount of blood the heart ... Cardiac output is calculated by the Stewart-Hamilton equation. C. O. l. i. =. L. i. ,. d. o. s. e. ×. 60. (. 1. −. P. C. V. ). ...
Cardiac cycle[edit]. The cardiac cycle is basically what happens during one heart-beat, and since it is continuous, a ... Ventricular systole. The resultant pressure closes the atrio-ventricular valves, and so the blood opens the semi-lunar valves ... Cardiac diastole. The pressure thats now in the pulmonary artery and aorta causes the semilunar valves to close, preventing ... When the heart is filled with blood, the muscles in the atrial walls contracts (known as the atrial systole), and this forces ...
Cardiac Hypertrophy. Diastolic Dysfunction. Cardiac Glycosides. Cardiac Fibrosis. Atrial Systole. Additional relevant MeSH ... Further, we will assess serum and cardiac MRI markers of myocardial fibrosis to determine the effect of collagen remodeling on ... Finally, we will examine the effects of short-term cardiac glycoside (inotropic) therapy on atrial systolic elastance, preload ... Primary hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease characterized by thickening (hypertrophy) of the left ...
... atrial systole explanation free. What is atrial systole? Meaning of atrial systole medical term. What does atrial systole mean? ... Looking for online definition of atrial systole in the Medical Dictionary? ... The rate varies normally with the cardiac cycle, being fastest during atrial diastole and slowest during atrial systole. ... Related to atrial systole: atrial diastole, Ventricular systole systole. [sis´to-le] the contraction, or period of contraction ...
  • Sandstede JJ, Johnson T, Harre K, Beer M, Hofmann S, Pabst T, Kenn W, Voelker W, Neubauer S, Hahn D (2002) Cardiac systolic rotation and contraction before and after valve replacement for aortic stenosis: a myocardial tagging study using MR imaging. (springer.com)
  • Modulation of respiratory therapy pressure reinforces the pumping action of the heart and results in increased cardiac output with decreased expenditure of myocardial energy output. (google.com)
  • Here, we utilize in vivo biophysical and genetic fate mapping zebrafish studies to reveal that altered hemodynamic forces due to cardiac injury activate a sequential endocardial-myocardial signaling cascade to direct cardiomyocyte reprogramming and heart regeneration. (elifesciences.org)
  • Based on these findings, we thus further explored whether altered blood flow forces during cardiac injury may similarly activate these signaling pathways to control myocardial reprogramming and regeneration. (elifesciences.org)
  • Cardiac fibrosis is also a main driver of heart failure with preserved ejection fraction (HFpEF) as it increases myocardial stiffness, thereby compromising the distensibility of the ventricles and impairing the filling capacity of the heart [ 10 ]. (mdpi.com)
  • Paroxysmal atria tachycardia (regular 140-220/min frequency)Often extra systole is followed by a - Atria fibrillation and atria fluttercompensatory pause, felt that a (irregular rhythm disturbances).disruption of the heart rhythm. (slideshare.net)
  • one or more output lists each corresponding to one value range of the one or more value ranges of the second cardiac parameter and including a plurality of atrio-ventricular delay (AVD) values each corresponding to one value range of the plurality of value ranges of the first cardiac parameter. (google.co.uk)
  • 2. The apparatus of claim 1 , wherein the first cardiac parameter comprises a measured intrinsic atrio-ventricular interval (AV). (google.co.uk)
  • These findings underscore the importance of treating both skeletal and cardiac muscles in DMD therapy. (nih.gov)
  • Presentation can range from asymptomatic to sudden cardiac death. (wikipedia.org)
  • 1. Sudden cessation of heartbeat and cardiac function, resulting in the loss of effective circulation. (thefreedictionary.com)
  • The NIOSH investigator the FD medical evaluations concluded that the physical stress of responding to the AFF staging area, and the physical exertion the AFF performed there, may have triggered his sudden The Fire Fighter Fatality Investigation and Pre ven tion cardiac death (SCD). (cdc.gov)
  • On November 16, 2014, a 40-year-old male career Pump Operator suffered sudden cardiac death after performing physical fitness training. (cdc.gov)
  • Obstruction in the region of the pulmonic valve may be extrinsic to the valve apparatus and may be produced by cardiac tumors or by aneurysm of the sinus of Valsalva. (medscape.com)