The restoration of the sequential order of contraction and relaxation of the HEART ATRIA and HEART VENTRICLES by atrio-biventricular pacing.
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.
Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.
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.
A device designed to stimulate, by electric impulses, contraction of the heart muscles. It may be temporary (external) or permanent (internal or internal-external).
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.
A form of heart block in which the electrical stimulation of HEART VENTRICLES is interrupted at either one of the branches of BUNDLE OF HIS thus preventing the simultaneous depolarization of the two ventricles.
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.
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.
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.
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.
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.
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.
Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.
Surgical insertion of a prosthesis.
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.
Surgically placed electric conductors through which ELECTRIC STIMULATION is delivered to or electrical activity is recorded from a specific point inside the body.
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.
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.
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.
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.
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.
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.
The fibrous tissue that replaces normal tissue during the process of WOUND HEALING.
A condition in which HEART VENTRICLES exhibit impaired function.
An electrical current applied to the HEART to terminate a disturbance of its rhythm, ARRHYTHMIAS, CARDIAC. (Stedman, 25th ed)
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).
A type of impedance plethysmography in which bioelectrical impedance is measured between electrodes positioned around the neck and around the lower thorax. It is used principally to calculate stroke volume and cardiac volume, but it is also related to myocardial contractility, thoracic fluid content, and circulation to the extremities.
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.
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.
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.
Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.
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.
Criteria and standards used for the determination of the appropriateness of the inclusion of patients with specific conditions in proposed treatment plans and the criteria used for the inclusion of subjects in various clinical trials and other research protocols.
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 hemodynamic and electrophysiological action of the right HEART VENTRICLE.
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.
Contractile activity of the MYOCARDIUM.
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)
Injuries caused by electric currents. The concept excludes electric burns (BURNS, ELECTRIC), but includes accidental electrocution and electric shock.
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.
Elements of limited time intervals, contributing to particular results or situations.
Period of contraction of the HEART, especially of the HEART VENTRICLES.
A condition in which the RIGHT VENTRICLE of the heart was functionally impaired. This condition usually leads to HEART FAILURE or MYOCARDIAL INFARCTION, and other cardiovascular complications. Diagnosis is made by measuring the diminished ejection fraction and a depressed level of motility of the right ventricular wall.
Radiographic visualization or recording of a vein after the injection of contrast medium.
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.
Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.
Computer systems utilized as adjuncts in the treatment of disease.
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).
Failure of equipment to perform to standard. The failure may be due to defects or improper use.
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)
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
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.
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).
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.
The chambers of the heart, to which the BLOOD returns from the circulation.
A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.
A nonparametric method of compiling LIFE TABLES or survival tables. It combines calculated probabilities of survival and estimates to allow for observations occurring beyond a measurement threshold, which are assumed to occur randomly. Time intervals are defined as ending each time an event occurs and are therefore unequal. (From Last, A Dictionary of Epidemiology, 1995)
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).
Production of an image when x-rays strike a fluorescent screen.
Radionuclide ventriculography where scintigraphic data is acquired during repeated cardiac cycles at specific times in the cycle, using an electrocardiographic synchronizer or gating device. Analysis of right ventricular function is difficult with this technique; that is best evaluated by first-pass ventriculography (VENTRICULOGRAPHY, FIRST-PASS).
Impaired impulse conduction from HEART ATRIA to HEART VENTRICLES. AV block can mean delayed or completely blocked impulse conduction.
The innermost layer of the heart, comprised of endothelial cells.
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)
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.
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.
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.
Methods of creating machines and devices.
The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.
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)
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.
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.
Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.
A measure of the quality of health care by assessment of unsuccessful results of management and procedures used in combating disease, in individual cases or series.
Works about clinical trials that involve at least one test treatment and one control treatment, concurrent enrollment and follow-up of the test- and control-treated groups, and in which the treatments to be administered are selected by a random process, such as the use of a random-numbers table.
The venous trunk which returns blood from the head, neck, upper extremities and chest.
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)
The exercise capacity of an individual as measured by endurance (maximal exercise duration and/or maximal attained work load) during an EXERCISE TEST.
Heart failure caused by abnormal myocardial contraction during SYSTOLE leading to defective cardiac emptying.
The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
Methods used in the diagnosis and treatment of behavioral, personality, and mental disorders.
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.
Small pumps, often implantable, designed for temporarily assisting the heart, usually the LEFT VENTRICLE, to pump blood. They consist of a pumping chamber and a power source, which may be partially or totally external to the body and activated by electromagnetic motors.
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.
The hollow, muscular organ that maintains the circulation of the blood.
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.
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).
The confinement of a patient in a hospital.
Examinations used to diagnose and treat heart conditions.
Any visual display of structural or functional patterns of organs or tissues for diagnostic evaluation. It includes measuring physiologic and metabolic responses to physical and chemical stimuli, as well as ultramicroscopy.
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 method in which either the observer(s) or the subject(s) is kept ignorant of the group to which the subjects are assigned.
A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.
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.
Works about controlled studies which are planned and carried out by several cooperating institutions to assess certain variables and outcomes in specific patient populations, for example, a multicenter study of congenital anomalies in children.
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.
Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.
A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.
The use of electronic equipment to observe or record physiologic processes while the patient undergoes normal daily activities.
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.
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.
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.
I'm sorry for any confusion, but 'Europe' is a geographical continent and not a medical term; therefore, it doesn't have a medical definition.
A type of cardiac arrhythmia with premature contractions of the HEART VENTRICLES. It is characterized by the premature QRS complex on ECG that is of abnormal shape and great duration (generally >129 msec). It is the most common form of all cardiac arrhythmias. Premature ventricular complexes have no clinical significance except in concurrence with heart diseases.
The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.
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.
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.
The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.
A condition associated with multiple episodes of sleep apnea which are distinguished from obstructive sleep apnea (SLEEP APNEA, OBSTRUCTIVE) by the complete cessation of efforts to breathe. This disorder is associated with dysfunction of central nervous system centers that regulate respiration.
Application of computer programs designed to assist the physician in solving a diagnostic problem.
A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.
The hemodynamic and electrophysiological action of the HEART ATRIA.
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
Backflow of blood from the RIGHT VENTRICLE into the RIGHT ATRIUM due to imperfect closure of the TRICUSPID VALVE.
A graphic means for assessing the ability of a screening test to discriminate between healthy and diseased persons; may also be used in other studies, e.g., distinguishing stimuli responses as to a faint stimuli or nonstimuli.
Method in which prolonged electrocardiographic recordings are made on a portable tape recorder (Holter-type system) or solid-state device ("real-time" system), while the patient undergoes normal daily activities. It is useful in the diagnosis and management of intermittent cardiac arrhythmias and transient myocardial ischemia.
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)
The hemodynamic and electrophysiological action of the HEART VENTRICLES.
Pathological conditions involving the HEART including its structural and functional abnormalities.
A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.
Statistical models used in survival analysis that assert that the effect of the study factors on the hazard rate in the study population is multiplicative and does not change over time.
A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)
Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.
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.
A method of recording heart motion and internal structures by combining ultrasonic imaging with exercise testing (EXERCISE TEST) or pharmacologic stress.
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.
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)
An activity in which the body advances at a slow to moderate pace by moving the feet in a coordinated fashion. This includes recreational walking, walking for fitness, and competitive race-walking.
Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
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.
A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.
Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.
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.
A method of comparing the cost of a program with its expected benefits in dollars (or other currency). The benefit-to-cost ratio is a measure of total return expected per unit of money spent. This analysis generally excludes consideration of factors that are not measured ultimately in economic terms. Cost effectiveness compares alternative ways to achieve a specific set of results.
Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)
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.
A measurement index derived from a modification of standard life-table procedures and designed to take account of the quality as well as the duration of survival. This index can be used in assessing the outcome of health care procedures or services. (BIOETHICS Thesaurus, 1994)

Cardiac resynchronization therapy with and without implantable cardioverter-defibrillator. (1/472)

Cardiac resynchronization therapy (CRT) is recommended to reduce morbidity and mortality in patients with New York Heart Association class III/IV, who are symptomatic despite optimal medical therapy, and who had a reduced left ventricle (LV) ejection fraction and electrical dyssynchrony. The effects of CRT are reflected mainly by the degree and location of dyssynchrony and by working in insertion of optimal LV lead site. Echocardiography and Doppler echocardiography are considered to be good tools to measure LV dyssynchrony directly. However, the large randomized trials have shown that no single echocardiographic measure of dyssynchrony is recommended to improve patient selection for CRT beyond current guidelines. There were several unsolved issues on CRT, such as patient selection, electrical or electromechanical dyssynchrony criteria to patients for CRT, indication of patients with a narrow or slightly prolonged QRS width, indication of patients with atrial fibrillation, and indication of patients with mild heart failure or asymptomatic LV dysfunction, and device selection; CRT alone (CRT-P) or CRT in combination with implantable cardioverter therapy (CRT-D). This review paper summarized the concept of therapy, the current evidence regarding the indications, effectiveness and safety of CRT-P and CRT-D in patients with LV dysfunction, and unsolved issues.  (+info)

Prevalence and risk factors related to infections of cardiac resynchronization therapy devices. (2/472)

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Resumption of sinus rhythm in patients with heart failure and permanent atrial fibrillation undergoing cardiac resynchronization therapy: a longitudinal observational study. (3/472)

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Upgrading to resynchronization therapy after chronic right ventricular pacing improves left ventricular remodelling. (4/472)

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Effectiveness of cardiac resynchronization therapy in mild congestive heart failure: systematic review and meta-analysis of randomized trials. (5/472)

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Clinical and echocardiographic correlates of improvement in left ventricular diastolic function after cardiac resynchronization therapy. (6/472)

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Impact of reduction in early- and late-systolic functional mitral regurgitation on reverse remodelling after cardiac resynchronization therapy. (7/472)

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Optimization of myocardial strain imaging and speckle tracking for resynchronization after congenital heart surgery in children. (8/472)

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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.

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.

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.

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%.

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.

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.

Bundle-branch block (BBB) is a type of conduction delay or block in the heart's electrical system that affects the way electrical impulses travel through the ventricles (the lower chambers of the heart). In BBB, one of the two main bundle branches that conduct electrical impulses to the ventricles is partially or completely blocked, causing a delay in the contraction of one of the ventricles.

There are two types of bundle-branch block: right bundle-branch block (RBBB) and left bundle-branch block (LBBB). In RBBB, the right bundle branch is affected, while in LBBB, the left bundle branch is affected. The symptoms and severity of BBB can vary depending on the underlying cause and the presence of other heart conditions.

In some cases, BBB may not cause any noticeable symptoms and may only be detected during a routine electrocardiogram (ECG). However, if BBB occurs along with other heart conditions such as coronary artery disease, heart failure, or cardiomyopathy, it can increase the risk of serious complications such as arrhythmias, syncope, and even sudden cardiac death.

Treatment for bundle-branch block depends on the underlying cause and the severity of the condition. In some cases, no treatment may be necessary, while in others, medications, pacemakers, or other treatments may be recommended to manage symptoms and prevent complications.

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.

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.

Ventricular remodeling is a structural adaptation process of the heart in response to stress or injury, such as myocardial infarction (heart attack) or pressure overload. This process involves changes in size, shape, and function of the ventricles (the lower chambers of the heart).

In ventricular remodeling, the heart muscle may thicken, enlarge, or become more stiff, leading to alterations in the pumping ability of the heart. These changes can ultimately result in cardiac dysfunction, heart failure, and an increased risk of arrhythmias (irregular heart rhythms).

Ventricular remodeling is often classified into two types:

1. Concentric remodeling: This occurs when the ventricular wall thickens (hypertrophy) without a significant increase in chamber size, leading to a decrease in the cavity volume and an increase in the thickness of the ventricular wall.
2. Eccentric remodeling: This involves an increase in both the ventricular chamber size and wall thickness due to the addition of new muscle cells (hyperplasia) or enlargement of existing muscle cells (hypertrophy). As a result, the overall shape of the ventricle becomes more spherical and less elliptical.

Both types of remodeling can negatively impact heart function and contribute to the development of heart failure. Close monitoring and appropriate treatment are essential for managing ventricular remodeling and preventing further complications.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

Cardiac output is a measure of the amount of blood that the heart pumps in one minute. It is calculated by multiplying the stroke volume (the amount of blood pumped by the left ventricle during each contraction) by the heart rate (the number of times the heart beats per minute). Low cardiac output refers to a condition in which the heart is not able to pump enough blood to meet the body's needs. This can occur due to various reasons such as heart failure, heart attack, or any other conditions that weaken the heart muscle. Symptoms of low cardiac output may include fatigue, shortness of breath, and decreased mental status. Treatment for low cardiac output depends on the underlying cause and may include medications, surgery, or medical devices to help support heart function.

A cicatrix is a medical term that refers to a scar or the process of scar formation. It is the result of the healing process following damage to body tissues, such as from an injury, wound, or surgery. During the healing process, specialized cells called fibroblasts produce collagen, which helps to reconnect and strengthen the damaged tissue. The resulting scar tissue may have a different texture, color, or appearance compared to the surrounding healthy tissue.

Cicatrix formation is a natural part of the body's healing response, but excessive scarring can sometimes cause functional impairment, pain, or cosmetic concerns. In such cases, various treatments may be used to minimize or improve the appearance of scars, including topical creams, steroid injections, laser therapy, and surgical revision.

Ventricular dysfunction is a term that refers to the impaired ability of the ventricles, which are the lower chambers of the heart, to fill with blood or pump it efficiently to the rest of the body. This condition can lead to reduced cardiac output and may cause symptoms such as shortness of breath, fatigue, and fluid retention.

There are two types of ventricular dysfunction:

1. Systolic dysfunction: This occurs when the ventricles cannot contract forcefully enough to eject an adequate amount of blood out of the heart during each beat. This is often due to damage to the heart muscle, such as that caused by a heart attack or cardiomyopathy.
2. Diastolic dysfunction: This happens when the ventricles are unable to relax and fill properly with blood between beats. This can be caused by stiffening of the heart muscle, often due to aging, high blood pressure, or diabetes.

Both types of ventricular dysfunction can lead to heart failure, a serious condition in which the heart is unable to pump blood effectively to meet the body's needs. Treatment for ventricular dysfunction may include medications, lifestyle changes, and in some cases, medical procedures or surgery.

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).

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.

Impedance cardiography is a non-invasive method to measure cardiac output and systemic vascular resistance. It uses low-frequency electrical currents passed through the thorax to measure changes in impedance or resistance to flow during each heartbeat. This allows for the calculation of stroke volume and cardiac output. Impedance cardiography can provide continuous, real-time monitoring of cardiovascular function, making it useful in critical care settings and for tracking changes in patients with heart failure or other cardiovascular conditions.

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.

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.

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.

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.

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.

Patient selection, in the context of medical treatment or clinical research, refers to the process of identifying and choosing appropriate individuals who are most likely to benefit from a particular medical intervention or who meet specific criteria to participate in a study. This decision is based on various factors such as the patient's diagnosis, stage of disease, overall health status, potential risks, and expected benefits. The goal of patient selection is to ensure that the selected individuals will receive the most effective and safe care possible while also contributing to meaningful research outcomes.

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.

Right Ventricular Function refers to the ability of the right ventricle (RV) of the heart to receive and eject blood during the cardiac cycle. The right ventricle is one of the four chambers of the heart and is responsible for pumping deoxygenated blood from the body to the lungs for re-oxygenation.

Right ventricular function can be assessed by measuring various parameters such as:

1. Right Ventricular Ejection Fraction (RVEF): It is the percentage of blood that is ejected from the right ventricle during each heartbeat. A normal RVEF ranges from 45-75%.
2. Right Ventricular Systolic Function: It refers to the ability of the right ventricle to contract and eject blood during systole (contraction phase). This can be assessed by measuring the tricuspid annular plane systolic excursion (TAPSE) or tissue Doppler imaging.
3. Right Ventricular Diastolic Function: It refers to the ability of the right ventricle to relax and fill with blood during diastole (relaxation phase). This can be assessed by measuring the right ventricular inflow pattern, tricuspid valve E/A ratio, or deceleration time.
4. Right Ventricular Afterload: It refers to the pressure that the right ventricle must overcome to eject blood into the pulmonary artery. Increased afterload can impair right ventricular function.

Abnormalities in right ventricular function can lead to various cardiovascular conditions such as pulmonary hypertension, heart failure, and arrhythmias.

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.

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.

Three-dimensional echocardiography (3DE) is a type of cardiac ultrasound that uses advanced technologies to create a real-time, detailed 3D image of the heart. This imaging technique provides a more comprehensive view of the heart's structure and function compared to traditional 2D echocardiography. By visualizing the heart from multiple angles, 3DE can help physicians better assess complex cardiac conditions, plan treatments, and monitor their effectiveness.

In a 3DE examination, a transducer (a handheld device that emits and receives sound waves) is placed on the chest to capture ultrasound data. This data is then processed by specialized software to create a 3D model of the heart. The procedure is non-invasive and typically takes less than an hour to complete.

Three-dimensional echocardiography has several clinical applications, including:

1. Evaluation of cardiac morphology and function in congenital heart disease
2. Assessment of valvular structure and function, such as mitral or aortic valve regurgitation or stenosis
3. Guidance during interventional procedures like transcatheter aortic valve replacement (TAVR)
4. Quantification of left ventricular volumes, ejection fraction, and mass
5. Assessment of right ventricular size and function
6. Detection and monitoring of cardiac tumors or other masses
7. Pre-surgical planning for complex heart surgeries

Overall, 3DE offers a more accurate and detailed view of the heart, allowing healthcare providers to make informed decisions about patient care and improve outcomes.

Electric injuries refer to damage to the body caused by exposure to electrical energy. This can occur when a person comes into contact with an electrical source, such as a power line or outlet, and the electrical current passes through the body. The severity of the injury depends on various factors, including the voltage and amperage of the electrical current, the duration of exposure, and the path the current takes through the body.

Electric injuries can cause a range of symptoms and complications, including burns, cardiac arrest, muscle damage, nerve damage, and fractures or dislocations (if the victim is thrown by the electrical shock). In some cases, electric injuries can be fatal. Treatment typically involves supportive care to stabilize the patient's vital signs, as well as specific interventions to address any complications that may have arisen as a result of the injury. Prevention measures include following safety guidelines when working with electricity and being aware of potential electrical hazards in one's environment.

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.

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.

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.

Right ventricular dysfunction is a condition characterized by the impaired ability of the right ventricle (one of the two pumping chambers in the heart) to fill with blood during the diastolic phase or eject blood during the systolic phase. This results in reduced cardiac output from the right ventricle, which can lead to various complications such as fluid accumulation in the body, particularly in the abdomen and lower extremities, and ultimately congestive heart failure if left untreated.

Right ventricular dysfunction can be caused by various factors, including damage to the heart muscle due to a heart attack, high blood pressure in the lungs (pulmonary hypertension), chronic lung diseases, congenital heart defects, viral infections, and certain medications. Symptoms of right ventricular dysfunction may include shortness of breath, fatigue, swelling in the legs, ankles, or abdomen, and a decreased tolerance for physical activity.

Diagnosis of right ventricular dysfunction typically involves a combination of medical history, physical examination, imaging tests such as echocardiography, cardiac MRI, or CT scan, and other diagnostic procedures such as electrocardiogram (ECG) or cardiac catheterization. Treatment options depend on the underlying cause but may include medications to reduce fluid buildup, improve heart function, and manage symptoms, as well as lifestyle modifications such as reducing salt intake and increasing physical activity levels. In severe cases, more invasive treatments such as surgery or implantable devices like pacemakers or ventricular assist devices may be necessary.

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.

Cardiac imaging techniques are diagnostic methods used to visualize and assess the structure and function of the heart. These techniques can be non-invasive or invasive, and they use various forms of energy such as sound waves, radiation, and magnetic fields to produce detailed images of the heart. Some common cardiac imaging techniques include:

1. Echocardiography: This technique uses ultrasound waves to create images of the heart's structure and function. It can provide information about the size and shape of the heart chambers, the thickness and movement of the heart walls, and the valves' function.
2. Cardiac Magnetic Resonance Imaging (MRI): This technique uses a strong magnetic field and radio waves to create detailed images of the heart's structure and function. It can provide information about the size and shape of the heart chambers, the thickness and movement of the heart walls, the valves' function, and the blood flow in the heart.
3. Computed Tomography (CT) Angiography: This technique uses X-rays to create detailed images of the heart's blood vessels. It can provide information about the presence and extent of blockages or narrowing in the coronary arteries.
4. Nuclear Cardiac Imaging: This technique uses small amounts of radioactive substances to produce images of the heart's blood flow. It can provide information about the size and function of the heart chambers, the presence of damaged heart muscle, and the extent of coronary artery disease.
5. Invasive Coronary Angiography: This technique involves inserting a catheter into a blood vessel in the arm or leg and guiding it to the heart's coronary arteries. A contrast dye is then injected through the catheter, and X-ray images are taken to visualize the blood flow in the coronary arteries. This technique can provide detailed information about the presence and extent of blockages or narrowing in the coronary arteries.

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.

Computer-assisted therapy, also known as computerized cognitive behavioral therapy (CCBT), refers to the use of computer programs or digital platforms to deliver therapeutic interventions that are typically guided by a trained professional. This approach often involves interactive activities and exercises designed to help individuals develop skills and strategies for managing various psychological, emotional, or behavioral issues.

The goal of computer-assisted therapy is to increase accessibility, affordability, and convenience of mental health services while maintaining the effectiveness of traditional face-to-face therapy. It can be used as a standalone treatment or as an adjunct to traditional therapy, depending on the individual's needs and preferences. Common applications of computer-assisted therapy include treating anxiety disorders, depression, post-traumatic stress disorder (PTSD), insomnia, and substance use disorders.

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.

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.

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.

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.

Echocardiography, Doppler, pulsed is a type of diagnostic medical test that uses ultrasound to create detailed images of the heart's structures and assess their function. In this technique, high-frequency sound waves are directed at the heart using a handheld device called a transducer, which is placed on the chest wall. The sound waves bounce off the heart structures and return to the transducer, which then sends the information to a computer that converts it into images.

Pulsed Doppler echocardiography is a specific type of Doppler ultrasound that allows for the measurement of blood flow velocities in the heart and great vessels. In this technique, the transducer emits short bursts or "pulses" of sound waves and then measures the time it takes for the echoes to return. By analyzing the frequency shifts of the returning echoes, the velocity and direction of blood flow can be determined. This information is particularly useful in evaluating valvular function, assessing the severity of valvular lesions, and identifying areas of turbulent or abnormal blood flow.

Overall, echocardiography, Doppler, pulsed is a valuable tool for diagnosing and managing a wide range of cardiovascular conditions, including heart valve disorders, congenital heart defects, cardiomyopathies, and pericardial diseases.

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.

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.

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.

"Recovery of function" is a term used in medical rehabilitation to describe the process in which an individual regains the ability to perform activities or tasks that were previously difficult or impossible due to injury, illness, or disability. This can involve both physical and cognitive functions. The goal of recovery of function is to help the person return to their prior level of independence and participation in daily activities, work, and social roles as much as possible.

Recovery of function may be achieved through various interventions such as physical therapy, occupational therapy, speech-language therapy, and other rehabilitation strategies. The specific approach used will depend on the individual's needs and the nature of their impairment. Recovery of function can occur spontaneously as the body heals, or it may require targeted interventions to help facilitate the process.

It is important to note that recovery of function does not always mean a full return to pre-injury or pre-illness levels of ability. Instead, it often refers to the person's ability to adapt and compensate for any remaining impairments, allowing them to achieve their maximum level of functional independence and quality of life.

The Kaplan-Meier estimate is a statistical method used to calculate the survival probability over time in a population. It is commonly used in medical research to analyze time-to-event data, such as the time until a patient experiences a specific event like disease progression or death. The Kaplan-Meier estimate takes into account censored data, which occurs when some individuals are lost to follow-up before experiencing the event of interest.

The method involves constructing a survival curve that shows the proportion of subjects still surviving at different time points. At each time point, the survival probability is calculated as the product of the conditional probabilities of surviving from one time point to the next. The Kaplan-Meier estimate provides an unbiased and consistent estimator of the survival function, even when censoring is present.

In summary, the Kaplan-Meier estimate is a crucial tool in medical research for analyzing time-to-event data and estimating survival probabilities over time while accounting for censored observations.

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.

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.

Gated Blood-Pool Imaging (GBPI) is a type of nuclear medicine test that uses radioactive material and a specialized camera to create detailed images of the heart and its function. In this procedure, a small amount of radioactive tracer is injected into the patient's bloodstream, which then accumulates in the heart muscle and the blood pool within the heart chambers.

The term "gated" refers to the use of an electrocardiogram (ECG) signal to synchronize the image acquisition with the heart's contractions. This allows for the visualization of the heart's motion during different phases of the cardiac cycle, providing valuable information about the size, shape, and contraction of the heart chambers, as well as the movement of the walls of the heart.

GBPI is often used to assess patients with known or suspected heart disease, such as valvular abnormalities, cardiomyopathies, or congenital heart defects. It can help diagnose and evaluate the severity of these conditions, guide treatment decisions, and monitor the effectiveness of therapy.

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.

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.

Sudden cardiac death (SCD) is a sudden, unexpected natural death caused by the cessation of cardiac activity. It is often caused by cardiac arrhythmias, particularly ventricular fibrillation, and is often associated with underlying heart disease, although it can occur in people with no known heart condition. SCD is typically defined as a natural death due to cardiac causes that occurs within one hour of the onset of symptoms, or if the individual was last seen alive in a normal state of health, it can be defined as occurring within 24 hours.

It's important to note that sudden cardiac arrest (SCA) is different from SCD, although they are related. SCA refers to the sudden cessation of cardiac activity, which if not treated immediately can lead to SCD.

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.

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.

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.

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.

The phrenic nerve is a motor nerve that originates from the cervical spine (C3-C5) and descends through the neck to reach the diaphragm, which is the primary muscle used for breathing. The main function of the phrenic nerve is to innervate the diaphragm and control its contraction and relaxation, thereby enabling respiration.

Damage or injury to the phrenic nerve can result in paralysis of the diaphragm, leading to difficulty breathing and potentially causing respiratory failure. Certain medical conditions, such as neuromuscular disorders, spinal cord injuries, and tumors, can affect the phrenic nerve and impair its function.

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.

Brain Natriuretic Peptide (BNP) is a type of natriuretic peptide that is primarily produced in the heart, particularly in the ventricles. Although it was initially identified in the brain, hence its name, it is now known that the cardiac ventricles are the main source of BNP in the body.

BNP is released into the bloodstream in response to increased stretching or distension of the heart muscle cells due to conditions such as heart failure, hypertension, and myocardial infarction (heart attack). Once released, BNP binds to specific receptors in the kidneys, causing an increase in urine production and excretion of sodium, which helps reduce fluid volume and decrease the workload on the heart.

BNP also acts as a hormone that regulates various physiological functions, including blood pressure, cardiac remodeling, and inflammation. Measuring BNP levels in the blood is a useful diagnostic tool for detecting and monitoring heart failure, as higher levels of BNP are associated with more severe heart dysfunction.

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.

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.

Treatment failure is a term used in medicine to describe the situation when a prescribed treatment or intervention is not achieving the desired therapeutic goals or objectives. This may occur due to various reasons, such as:

1. Development of drug resistance by the pathogen or disease being treated.
2. Inadequate dosage or frequency of the medication.
3. Poor adherence or compliance to the treatment regimen by the patient.
4. The presence of underlying conditions or comorbidities that may affect the efficacy of the treatment.
5. The severity or progression of the disease despite appropriate treatment.

When treatment failure occurs, healthcare providers may need to reassess the patient's condition and modify the treatment plan accordingly, which may include adjusting the dosage, changing the medication, adding new medications, or considering alternative treatments.

A randomized controlled trial (RCT) is a type of clinical study in which participants are randomly assigned to receive either the experimental intervention or the control condition, which may be a standard of care, placebo, or no treatment. The goal of an RCT is to minimize bias and ensure that the results are due to the intervention being tested rather than other factors. This design allows for a comparison between the two groups to determine if there is a significant difference in outcomes. RCTs are often considered the gold standard for evaluating the safety and efficacy of medical interventions, as they provide a high level of evidence for causal relationships between the intervention and health outcomes.

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.

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.

Exercise tolerance is a term used to describe the ability of an individual to perform physical activity or exercise without experiencing symptoms such as shortness of breath, chest pain, or undue fatigue. It is often used as a measure of cardiovascular fitness and can be assessed through various tests, such as a stress test or a six-minute walk test. Exercise intolerance may indicate the presence of underlying medical conditions, such as heart disease, lung disease, or deconditioning.

Heart failure, systolic is a type of heart failure in which the heart's lower chambers, the ventricles, are not able to contract with enough force to pump an adequate amount of blood throughout the body. This means that the heart cannot effectively pump oxygenated blood to meet the body's needs, leading to symptoms such as shortness of breath, fatigue, and fluid buildup in the lungs and other parts of the body.

Systolic heart failure is often caused by damage to the heart muscle, such as from a heart attack or long-standing high blood pressure. Over time, this damage can weaken the heart muscle and make it harder for the ventricles to contract with enough force to pump blood efficiently.

Treatment for systolic heart failure typically involves medications to help improve heart function, reduce symptoms, and prevent further damage to the heart. Lifestyle changes, such as following a healthy diet, getting regular exercise, and quitting smoking, can also help manage this condition. In some cases, more advanced treatments such as implantable devices or heart transplantation may be necessary.

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.

Psychological techniques generally refer to various methods and approaches used in psychology to help individuals manage their emotions, thoughts, behaviors, and relationships. These techniques are often based on scientific research and theories from fields such as cognitive-behavioral therapy, psychodynamic therapy, humanistic psychology, and positive psychology. Here are some examples of psychological techniques:

1. Cognitive restructuring: This technique involves identifying and challenging negative or distorted thinking patterns to replace them with more realistic and adaptive ones.
2. Mindfulness meditation: Practicing mindfulness means focusing on the present moment without judgment, which can help reduce stress, anxiety, and depression.
3. Exposure therapy: This is a technique used to treat phobias and anxiety disorders by gradually exposing individuals to their fears in a safe and controlled environment.
4. Systematic desensitization: A form of exposure therapy that involves pairing relaxation techniques with increasingly intense exposures to a feared stimulus.
5. Journaling: Writing down thoughts and feelings can help individuals process emotions, gain self-awareness, and track progress in therapy.
6. Role-playing: Acting out scenarios or conversations can help people practice new skills, build confidence, and improve communication.
7. Mental imagery: Visualizing positive outcomes or situations can help change negative thought patterns and promote personal growth.
8. Emotion regulation strategies: Learning to identify, understand, and manage emotions is an essential skill for mental well-being. Techniques include deep breathing, progressive muscle relaxation, and distraction.
9. Behavioral activation: Engaging in enjoyable activities can help improve mood and reduce symptoms of depression.
10. Assertiveness training: This technique teaches individuals how to express their needs and desires clearly and respectfully while maintaining healthy boundaries.

These psychological techniques are often used by mental health professionals, such as psychologists, therapists, and counselors, to help clients overcome various emotional and behavioral challenges. However, some techniques can also be self-taught or practiced independently with the guidance of books, online resources, or support groups.

Ventricular Fibrillation (VF) is a type of cardiac arrhythmia, which is an abnormal heart rhythm. In VF, the ventricles, which are the lower chambers of the heart, beat in a rapid and unorganized manner. This results in the heart being unable to pump blood effectively to the rest of the body, leading to immediate circulatory collapse and cardiac arrest if not treated promptly. It is often caused by underlying heart conditions such as coronary artery disease, structural heart problems, or electrolyte imbalances. VF is a medical emergency that requires immediate defibrillation to restore a normal heart rhythm.

Heart-assist devices, also known as mechanical circulatory support devices, are medical equipment designed to help the heart function more efficiently. These devices can be used in patients with advanced heart failure who are not responding to medication or other treatments. They work by taking over some or all of the heart's pumping functions, reducing the workload on the heart and improving blood flow to the rest of the body.

There are several types of heart-assist devices, including:

1. Intra-aortic balloon pumps (IABPs): These devices are inserted into the aorta, the large artery that carries blood from the heart to the rest of the body. The IABP inflates and deflates in time with the heartbeat, helping to improve blood flow to the coronary arteries and reduce the workload on the heart.
2. Ventricular assist devices (VADs): These devices are more invasive than IABPs and are used to support the function of one or both ventricles, the lower chambers of the heart. VADs can be used to support the heart temporarily while a patient recovers from surgery or heart failure, or they can be used as a long-term solution for patients who are not candidates for a heart transplant.
3. Total artificial hearts (TAHs): These devices replace both ventricles and all four valves of the heart. TAHs are used in patients who are not candidates for a heart transplant and have severe biventricular failure, meaning that both ventricles are no longer functioning properly.

Heart-assist devices can be life-saving for some patients with advanced heart failure, but they also carry risks, such as infection, bleeding, and device malfunction. As with any medical treatment, the benefits and risks of using a heart-assist device must be carefully weighed for each individual patient.

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic technique that uses a strong magnetic field and radio waves to create detailed cross-sectional images of the body's internal structures. In MRI, Cine is a specific mode of imaging that allows for the evaluation of moving structures, such as the heart, by acquiring and displaying a series of images in rapid succession. This technique is particularly useful in cardiac imaging, where it can help assess heart function, valve function, and blood flow. The term "Cine" refers to the continuous playback of these images, similar to watching a movie, allowing doctors to evaluate motion and timing within the heart.

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.

Cardiac volume refers to the amount of blood contained within the heart chambers at any given point in time. It is a measure of the volume of blood that is being moved by the heart during each cardiac cycle, which includes both systole (contraction) and diastole (relaxation) phases.

There are several types of cardiac volumes that are commonly measured or estimated using medical imaging techniques such as echocardiography or cardiac magnetic resonance imaging (MRI). These include:

1. End-diastolic volume (EDV): This is the volume of blood in the heart chambers at the end of diastole, when the heart chambers are fully filled with blood.
2. End-systolic volume (ESV): This is the volume of blood in the heart chambers at the end of systole, when the heart chambers have contracted and ejected most of the blood.
3. Stroke volume (SV): This is the difference between the EDV and ESV, and represents the amount of blood that is pumped out of the heart with each beat.
4. Cardiac output (CO): This is the product of the stroke volume and heart rate, and represents the total amount of blood that is pumped by the heart in one minute.

Abnormalities in cardiac volumes can indicate various heart conditions such as heart failure, valvular heart disease, or cardiomyopathy.

Observer variation, also known as inter-observer variability or measurement agreement, refers to the difference in observations or measurements made by different observers or raters when evaluating the same subject or phenomenon. It is a common issue in various fields such as medicine, research, and quality control, where subjective assessments are involved.

In medical terms, observer variation can occur in various contexts, including:

1. Diagnostic tests: Different radiologists may interpret the same X-ray or MRI scan differently, leading to variations in diagnosis.
2. Clinical trials: Different researchers may have different interpretations of clinical outcomes or adverse events, affecting the consistency and reliability of trial results.
3. Medical records: Different healthcare providers may document medical histories, physical examinations, or treatment plans differently, leading to inconsistencies in patient care.
4. Pathology: Different pathologists may have varying interpretations of tissue samples or laboratory tests, affecting diagnostic accuracy.

Observer variation can be minimized through various methods, such as standardized assessment tools, training and calibration of observers, and statistical analysis of inter-rater reliability.

Hospitalization is the process of admitting a patient to a hospital for the purpose of receiving medical treatment, surgery, or other health care services. It involves staying in the hospital as an inpatient, typically under the care of doctors, nurses, and other healthcare professionals. The length of stay can vary depending on the individual's medical condition and the type of treatment required. Hospitalization may be necessary for a variety of reasons, such as to receive intensive care, to undergo diagnostic tests or procedures, to recover from surgery, or to manage chronic illnesses or injuries.

Heart function tests are a group of diagnostic exams that are used to evaluate the structure and functioning of the heart. These tests help doctors assess the pumping efficiency of the heart, the flow of blood through the heart, the presence of any heart damage, and the overall effectiveness of the heart in delivering oxygenated blood to the rest of the body.

Some common heart function tests include:

1. Echocardiogram (Echo): This test uses sound waves to create detailed images of the heart's structure and functioning. It can help detect any damage to the heart muscle, valves, or sac surrounding the heart.
2. Nuclear Stress Test: This test involves injecting a small amount of radioactive substance into the patient's bloodstream and taking images of the heart while it is at rest and during exercise. The test helps evaluate blood flow to the heart and detect any areas of reduced blood flow, which could indicate coronary artery disease.
3. Cardiac Magnetic Resonance Imaging (MRI): This test uses magnetic fields and radio waves to create detailed images of the heart's structure and function. It can help detect any damage to the heart muscle, valves, or other structures of the heart.
4. Electrocardiogram (ECG): This test measures the electrical activity of the heart and helps detect any abnormalities in the heart's rhythm or conduction system.
5. Exercise Stress Test: This test involves walking on a treadmill or riding a stationary bike while being monitored for changes in heart rate, blood pressure, and ECG readings. It helps evaluate exercise capacity and detect any signs of coronary artery disease.
6. Cardiac Catheterization: This is an invasive procedure that involves inserting a catheter into the heart to measure pressures and take samples of blood from different parts of the heart. It can help diagnose various heart conditions, including heart valve problems, congenital heart defects, and coronary artery disease.

Overall, heart function tests play an essential role in diagnosing and managing various heart conditions, helping doctors provide appropriate treatment and improve patient outcomes.

Diagnostic imaging is a medical specialty that uses various technologies to produce visual representations of the internal structures and functioning of the body. These images are used to diagnose injury, disease, or other abnormalities and to monitor the effectiveness of treatment. Common modalities of diagnostic imaging include:

1. Radiography (X-ray): Uses ionizing radiation to produce detailed images of bones, teeth, and some organs.
2. Computed Tomography (CT) Scan: Combines X-ray technology with computer processing to create cross-sectional images of the body.
3. Magnetic Resonance Imaging (MRI): Uses a strong magnetic field and radio waves to generate detailed images of soft tissues, organs, and bones.
4. Ultrasound: Employs high-frequency sound waves to produce real-time images of internal structures, often used for obstetrics and gynecology.
5. Nuclear Medicine: Involves the administration of radioactive tracers to assess organ function or detect abnormalities within the body.
6. Positron Emission Tomography (PET) Scan: Uses a small amount of radioactive material to produce detailed images of metabolic activity in the body, often used for cancer detection and monitoring treatment response.
7. Fluoroscopy: Utilizes continuous X-ray imaging to observe moving structures or processes within the body, such as swallowing studies or angiography.

Diagnostic imaging plays a crucial role in modern medicine, allowing healthcare providers to make informed decisions about patient care and treatment plans.

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.

A single-blind method in medical research is a study design where the participants are unaware of the group or intervention they have been assigned to, but the researchers conducting the study know which participant belongs to which group. This is done to prevent bias from the participants' expectations or knowledge of their assignment, while still allowing the researchers to control the study conditions and collect data.

In a single-blind trial, the participants do not know whether they are receiving the active treatment or a placebo (a sham treatment that looks like the real thing but has no therapeutic effect), whereas the researcher knows which participant is receiving which intervention. This design helps to ensure that the participants' responses and outcomes are not influenced by their knowledge of the treatment assignment, while still allowing the researchers to assess the effectiveness or safety of the intervention being studied.

Single-blind methods are commonly used in clinical trials and other medical research studies where it is important to minimize bias and control for confounding variables that could affect the study results.

Survival analysis is a branch of statistics that deals with the analysis of time to event data. It is used to estimate the time it takes for a certain event of interest to occur, such as death, disease recurrence, or treatment failure. The event of interest is called the "failure" event, and survival analysis estimates the probability of not experiencing the failure event until a certain point in time, also known as the "survival" probability.

Survival analysis can provide important information about the effectiveness of treatments, the prognosis of patients, and the identification of risk factors associated with the event of interest. It can handle censored data, which is common in medical research where some participants may drop out or be lost to follow-up before the event of interest occurs.

Survival analysis typically involves estimating the survival function, which describes the probability of surviving beyond a certain time point, as well as hazard functions, which describe the instantaneous rate of failure at a given time point. Other important concepts in survival analysis include median survival times, restricted mean survival times, and various statistical tests to compare survival curves between groups.

Ventricular pressure refers to the pressure within the ventricles, which are the lower chambers of the heart. In the left ventricle, the pressure measures the force that the blood exerts on the walls as it is pumped out to the rest of the body. In the right ventricle, the pressure measures the force of the blood being pumped into the pulmonary artery and ultimately to the lungs for oxygenation.

Normally, the left ventricular pressure ranges from 8-12 mmHg at rest when the heart is relaxed (diastolic pressure) and can increase up to 120-140 mmHg during contraction (systolic pressure). The right ventricular pressure is lower than the left, with a normal diastolic pressure of 0-6 mmHg and a systolic pressure ranging from 15-30 mmHg.

Abnormal ventricular pressures can indicate various heart conditions, such as heart failure, hypertension, or valvular heart disease. Regular monitoring of ventricular pressure is essential in managing these conditions and ensuring proper heart function.

A multicenter study is a type of clinical research study that involves multiple centers or institutions. These studies are often conducted to increase the sample size and diversity of the study population, which can improve the generalizability of the study results. In a multicenter study, data is collected from participants at multiple sites and then analyzed together to identify patterns, trends, and relationships in the data. This type of study design can be particularly useful for researching rare diseases or conditions, or for testing new treatments or interventions that require a large number of participants.

Multicenter studies can be either interventional (where participants are randomly assigned to receive different treatments or interventions) or observational (where researchers collect data on participants' characteristics and outcomes without intervening). In both cases, it is important to ensure standardization of data collection and analysis procedures across all study sites to minimize bias and ensure the validity and reliability of the results.

Multicenter studies can provide valuable insights into the effectiveness and safety of new treatments or interventions, as well as contribute to our understanding of disease mechanisms and risk factors. However, they can also be complex and expensive to conduct, requiring careful planning, coordination, and management to ensure their success.

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.

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.

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.

Ambulatory monitoring is a medical practice that involves the continuous or intermittent recording of physiological parameters in a patient who is mobile and able to perform their usual activities while outside of a hospital or clinical setting. This type of monitoring allows healthcare professionals to evaluate a patient's condition over an extended period, typically 24 hours or more, in their natural environment.

Ambulatory monitoring can be used to diagnose and manage various medical conditions such as hypertension, cardiac arrhythmias, sleep disorders, and mobility issues. Common methods of ambulatory monitoring include:

1. Holter monitoring: A small, portable device that records the electrical activity of the heart for 24-48 hours or more.
2. Ambulatory blood pressure monitoring (ABPM): A device that measures blood pressure at regular intervals throughout the day and night.
3. Event monitors: Devices that record heart rhythms only when symptoms occur or when activated by the patient.
4. Actigraphy: A non-invasive method of monitoring sleep-wake patterns, physical activity, and circadian rhythms using a wristwatch-like device.
5. Continuous glucose monitoring (CGM): A device that measures blood sugar levels continuously throughout the day and night.

Overall, ambulatory monitoring provides valuable information about a patient's physiological status in their natural environment, allowing healthcare professionals to make informed decisions regarding diagnosis, treatment, and management of medical conditions.

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.

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.

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.

I'm sorry for any confusion, but the term "Europe" is a geographical and political designation, rather than a medical one. It refers to the continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. Europe is made up of approximately 50 countries, depending on how one defines a "country."

If you have any questions related to medical terminology or health-related topics, I'd be happy to help answer them!

Ventricular Premature Complexes (VPCs), also known as Ventricular Extrasystoles or Premature Ventricular Contractions (PVCs), are extra heartbeats that originate in the ventricles, the lower chambers of the heart. These premature beats disrupt the normal sequence of electrical impulses in the heart and cause the ventricles to contract earlier than they should.

VPCs can result in a noticeable "skipped" or "extra" beat sensation, often followed by a stronger beat as the heart returns to its regular rhythm. They may occur occasionally in healthy individuals with no underlying heart condition, but frequent VPCs could indicate an underlying issue such as heart disease, electrolyte imbalance, or digitalis toxicity. In some cases, VPCs can be harmless and require no treatment; however, if they are frequent or associated with structural heart problems, further evaluation and management may be necessary to prevent potential complications like reduced cardiac output or heart failure.

Equipment Failure Analysis is a process of identifying the cause of failure in medical equipment or devices. This involves a systematic examination and evaluation of the equipment, its components, and operational history to determine why it failed. The analysis may include physical inspection, chemical testing, and review of maintenance records, as well as assessment of design, manufacturing, and usage factors that may have contributed to the failure.

The goal of Equipment Failure Analysis is to identify the root cause of the failure, so that corrective actions can be taken to prevent similar failures in the future. This is important in medical settings to ensure patient safety and maintain the reliability and effectiveness of medical equipment.

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.

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.

Medical survival rate is a statistical measure used to determine the percentage of patients who are still alive for a specific period of time after their diagnosis or treatment for a certain condition or disease. It is often expressed as a five-year survival rate, which refers to the proportion of people who are alive five years after their diagnosis. Survival rates can be affected by many factors, including the stage of the disease at diagnosis, the patient's age and overall health, the effectiveness of treatment, and other health conditions that the patient may have. It is important to note that survival rates are statistical estimates and do not necessarily predict an individual patient's prognosis.

Central sleep apnea (CSA) is a type of sleep-disordered breathing characterized by repeated cessations in breathing during sleep due to the brain's failure to transmit signals to the respiratory muscles that control breathing. Unlike obstructive sleep apnea (OSA), which results from airway obstruction, CSA occurs when the brain fails to send the necessary signals to the diaphragm and intercostal muscles to initiate or maintain respiratory efforts during sleep.

Central sleep apneas are usually associated with decreased oxygen saturation levels and can lead to frequent arousals from sleep, causing excessive daytime sleepiness, fatigue, and impaired cognitive function. CSA is often related to underlying medical conditions such as heart failure, stroke, or brainstem injury, and it may also be caused by the use of certain medications, including opioids.

There are several types of central sleep apnea, including:

1. Primary Central Sleep Apnea: This type occurs without any underlying medical condition or medication use.
2. Cheyne-Stokes Breathing: A pattern of central sleep apnea commonly seen in individuals with heart failure or stroke. It is characterized by a crescendo-decrescendo pattern of breathing, with periods of hyperventilation followed by hypoventilation and apnea.
3. High-Altitude Periodic Breathing: This type occurs at high altitudes due to the reduced oxygen levels and is usually reversible upon returning to lower altitudes.
4. Complex or Mixed Sleep Apnea: A combination of both central and obstructive sleep apneas, often observed in patients with OSA who are treated with continuous positive airway pressure (CPAP) therapy. In some cases, the central component may resolve over time with continued CPAP use.

Diagnosis of CSA typically involves a sleep study (polysomnography), which monitors various physiological parameters during sleep, such as brain waves, eye movements, muscle activity, heart rate, and breathing patterns. Treatment options for central sleep apnea depend on the underlying cause and may include medications, adjustments in medication dosages, or the use of devices that assist with breathing, such as adaptive servo-ventilation (ASV) or bilevel positive airway pressure (BiPAP) therapy.

Computer-assisted diagnosis (CAD) is the use of computer systems to aid in the diagnostic process. It involves the use of advanced algorithms and data analysis techniques to analyze medical images, laboratory results, and other patient data to help healthcare professionals make more accurate and timely diagnoses. CAD systems can help identify patterns and anomalies that may be difficult for humans to detect, and they can provide second opinions and flag potential errors or uncertainties in the diagnostic process.

CAD systems are often used in conjunction with traditional diagnostic methods, such as physical examinations and patient interviews, to provide a more comprehensive assessment of a patient's health. They are commonly used in radiology, pathology, cardiology, and other medical specialties where imaging or laboratory tests play a key role in the diagnostic process.

While CAD systems can be very helpful in the diagnostic process, they are not infallible and should always be used as a tool to support, rather than replace, the expertise of trained healthcare professionals. It's important for medical professionals to use their clinical judgment and experience when interpreting CAD results and making final diagnoses.

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.

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 myocytes are the muscle cells that make up the heart muscle, also known as the myocardium. These specialized cells are responsible for contracting and relaxing in a coordinated manner to pump blood throughout the body. They differ from skeletal muscle cells in several ways, including their ability to generate their own electrical impulses, which allows the heart to function as an independent rhythmical pump. Cardiac myocytes contain sarcomeres, the contractile units of the muscle, and are connected to each other by intercalated discs that help coordinate contraction and ensure the synchronous beating of the heart.

Tricuspid valve insufficiency, also known as tricuspid regurgitation, is a cardiac condition in which the tricuspid valve located between the right atrium and right ventricle of the heart does not close properly, allowing blood to flow back into the right atrium during contraction of the right ventricle. This results in a portion of the blood being pumped inefficiently, which can lead to volume overload of the right side of the heart and potentially result in symptoms such as fatigue, weakness, shortness of breath, and fluid retention. The condition can be congenital or acquired, with common causes including dilated cardiomyopathy, infective endocarditis, rheumatic heart disease, and trauma.

A Receiver Operating Characteristic (ROC) curve is a graphical representation used in medical decision-making and statistical analysis to illustrate the performance of a binary classifier system, such as a diagnostic test or a machine learning algorithm. It's a plot that shows the tradeoff between the true positive rate (sensitivity) and the false positive rate (1 - specificity) for different threshold settings.

The x-axis of an ROC curve represents the false positive rate (the proportion of negative cases incorrectly classified as positive), while the y-axis represents the true positive rate (the proportion of positive cases correctly classified as positive). Each point on the curve corresponds to a specific decision threshold, with higher points indicating better performance.

The area under the ROC curve (AUC) is a commonly used summary measure that reflects the overall performance of the classifier. An AUC value of 1 indicates perfect discrimination between positive and negative cases, while an AUC value of 0.5 suggests that the classifier performs no better than chance.

ROC curves are widely used in healthcare to evaluate diagnostic tests, predictive models, and screening tools for various medical conditions, helping clinicians make informed decisions about patient care based on the balance between sensitivity and specificity.

Ambulatory electrocardiography, also known as ambulatory ECG or Holter monitoring, is a non-invasive method of recording the electrical activity of the heart over an extended period of time (typically 24 hours or more) while the patient goes about their daily activities. The device used to record the ECG is called a Holter monitor, which consists of a small, portable recorder that is attached to the patient's chest with electrodes.

The recorded data provides information on any abnormalities in the heart's rhythm or electrical activity during different stages of activity and rest, allowing healthcare providers to diagnose and evaluate various cardiac conditions such as arrhythmias, ischemia, and infarction. The ability to monitor the heart's activity over an extended period while the patient performs their normal activities provides valuable information that may not be captured during a standard ECG, which only records the heart's electrical activity for a few seconds.

In summary, ambulatory electrocardiography is a diagnostic tool used to evaluate the electrical activity of the heart over an extended period, allowing healthcare providers to diagnose and manage various cardiac conditions.

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.

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.

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.

Quality of Life (QOL) is a broad, multidimensional concept that usually includes an individual's physical health, psychological state, level of independence, social relationships, personal beliefs, and their relationship to salient features of their environment. It reflects the impact of disease and treatment on a patient's overall well-being and ability to function in daily life.

The World Health Organization (WHO) defines QOL as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns." It is a subjective concept, meaning it can vary greatly from person to person.

In healthcare, QOL is often used as an outcome measure in clinical trials and other research studies to assess the impact of interventions or treatments on overall patient well-being.

Proportional hazards models are a type of statistical analysis used in medical research to investigate the relationship between covariates (predictor variables) and survival times. The most common application of proportional hazards models is in the Cox regression model, which is named after its developer, Sir David Cox.

In a proportional hazards model, the hazard rate or risk of an event occurring at a given time is assumed to be proportional to the hazard rate of a reference group, after adjusting for the covariates. This means that the ratio of the hazard rates between any two individuals remains constant over time, regardless of their survival times.

Mathematically, the hazard function h(t) at time t for an individual with a set of covariates X can be expressed as:

h(t|X) = h0(t) \* exp(β1X1 + β2X2 + ... + βpXp)

where h0(t) is the baseline hazard function, X1, X2, ..., Xp are the covariates, and β1, β2, ..., βp are the regression coefficients that represent the effect of each covariate on the hazard rate.

The assumption of proportionality is crucial in the interpretation of the results from a Cox regression model. If the assumption is violated, then the estimated regression coefficients may be biased and misleading. Therefore, it is important to test for the proportional hazards assumption before interpreting the results of a Cox regression analysis.

Nonparametric statistics is a branch of statistics that does not rely on assumptions about the distribution of variables in the population from which the sample is drawn. In contrast to parametric methods, nonparametric techniques make fewer assumptions about the data and are therefore more flexible in their application. Nonparametric tests are often used when the data do not meet the assumptions required for parametric tests, such as normality or equal variances.

Nonparametric statistical methods include tests such as the Wilcoxon rank-sum test (also known as the Mann-Whitney U test) for comparing two independent groups, the Wilcoxon signed-rank test for comparing two related groups, and the Kruskal-Wallis test for comparing more than two independent groups. These tests use the ranks of the data rather than the actual values to make comparisons, which allows them to be used with ordinal or continuous data that do not meet the assumptions of parametric tests.

Overall, nonparametric statistics provide a useful set of tools for analyzing data in situations where the assumptions of parametric methods are not met, and can help researchers draw valid conclusions from their data even when the data are not normally distributed or have other characteristics that violate the assumptions of parametric tests.

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.

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.

Stress echocardiography is a medical test that uses ultrasound imaging to assess how well your heart muscles are pumping blood and how well they respond to stress. It can help diagnose and evaluate coronary artery disease, valvular heart disease, and other cardiac conditions.

During the test, you will be asked to exercise on a treadmill or stationary bike while your heart rate and blood pressure are monitored. At peak exercise, a healthcare professional will take ultrasound images of your heart to evaluate its structure and function. If you are unable to exercise, medication may be given to simulate the effects of exercise on your heart.

The test can help identify areas of your heart that aren't receiving enough oxygen-rich blood due to blocked or narrowed arteries. It can also assess how well your heart valves are functioning and whether there are any structural abnormalities in your heart. Your healthcare provider will use the results of the test to develop a treatment plan tailored to your individual needs.

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.

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.

Medical science often defines and describes "walking" as a form of locomotion or mobility where an individual repeatedly lifts and sets down each foot to move forward, usually bearing weight on both legs. It is a complex motor activity that requires the integration and coordination of various systems in the human body, including the musculoskeletal, neurological, and cardiovascular systems.

Walking involves several components such as balance, coordination, strength, and endurance. The ability to walk independently is often used as a measure of functional mobility and overall health status. However, it's important to note that the specific definition of walking may vary depending on the context and the medical or scientific field in question.

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.

An algorithm is not a medical term, but rather a concept from computer science and mathematics. In the context of medicine, algorithms are often used to describe step-by-step procedures for diagnosing or managing medical conditions. These procedures typically involve a series of rules or decision points that help healthcare professionals make informed decisions about patient care.

For example, an algorithm for diagnosing a particular type of heart disease might involve taking a patient's medical history, performing a physical exam, ordering certain diagnostic tests, and interpreting the results in a specific way. By following this algorithm, healthcare professionals can ensure that they are using a consistent and evidence-based approach to making a diagnosis.

Algorithms can also be used to guide treatment decisions. For instance, an algorithm for managing diabetes might involve setting target blood sugar levels, recommending certain medications or lifestyle changes based on the patient's individual needs, and monitoring the patient's response to treatment over time.

Overall, algorithms are valuable tools in medicine because they help standardize clinical decision-making and ensure that patients receive high-quality care based on the latest scientific evidence.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

The double-blind method is a study design commonly used in research, including clinical trials, to minimize bias and ensure the objectivity of results. In this approach, both the participants and the researchers are unaware of which group the participants are assigned to, whether it be the experimental group or the control group. This means that neither the participants nor the researchers know who is receiving a particular treatment or placebo, thus reducing the potential for bias in the evaluation of outcomes. The assignment of participants to groups is typically done by a third party not involved in the study, and the codes are only revealed after all data have been collected and analyzed.

Computer-assisted image interpretation is the use of computer algorithms and software to assist healthcare professionals in analyzing and interpreting medical images. These systems use various techniques such as pattern recognition, machine learning, and artificial intelligence to help identify and highlight abnormalities or patterns within imaging data, such as X-rays, CT scans, MRI, and ultrasound images. The goal is to increase the accuracy, consistency, and efficiency of image interpretation, while also reducing the potential for human error. It's important to note that these systems are intended to assist healthcare professionals in their decision making process and not to replace them.

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.

Cost-benefit analysis (CBA) is a systematic process used to compare the costs and benefits of different options to determine which one provides the greatest net benefit. In a medical context, CBA can be used to evaluate the value of medical interventions, treatments, or policies by estimating and monetizing all the relevant costs and benefits associated with each option.

The costs included in a CBA may include direct costs such as the cost of the intervention or treatment itself, as well as indirect costs such as lost productivity or time away from work. Benefits may include improved health outcomes, reduced morbidity or mortality, and increased quality of life.

Once all the relevant costs and benefits have been identified and quantified, they are typically expressed in monetary terms to allow for a direct comparison. The option with the highest net benefit (i.e., the difference between total benefits and total costs) is considered the most cost-effective.

It's important to note that CBA has some limitations and can be subject to various biases and assumptions, so it should be used in conjunction with other evaluation methods to ensure a comprehensive understanding of the value of medical interventions or policies.

A cross-over study is a type of experimental design in which participants receive two or more interventions in a specific order. After a washout period, each participant receives the opposite intervention(s). The primary advantage of this design is that it controls for individual variability by allowing each participant to act as their own control.

In medical research, cross-over studies are often used to compare the efficacy or safety of two treatments. For example, a researcher might conduct a cross-over study to compare the effectiveness of two different medications for treating high blood pressure. Half of the participants would be randomly assigned to receive one medication first and then switch to the other medication after a washout period. The other half of the participants would receive the opposite order of treatments.

Cross-over studies can provide valuable insights into the relative merits of different interventions, but they also have some limitations. For example, they may not be suitable for studying conditions that are chronic or irreversible, as it may not be possible to completely reverse the effects of the first intervention before administering the second one. Additionally, carryover effects from the first intervention can confound the results if they persist into the second treatment period.

Overall, cross-over studies are a useful tool in medical research when used appropriately and with careful consideration of their limitations.

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.

Quality-Adjusted Life Years (QALYs) is a measure of health outcomes that combines both the quality and quantity of life lived in a single metric. It is often used in economic evaluations of healthcare interventions to estimate their value for money. QALYs are calculated by multiplying the number of years of life gained by a weighting factor that reflects the quality of life experienced during those years, typically on a scale from 0 (representing death) to 1 (representing perfect health). For example, if a healthcare intervention extends a person's life by an additional five years but they experience only 80% of full health during that time, the QALY gain would be 4 (5 x 0.8). This measure allows for comparisons to be made between different interventions and their impact on both length and quality of life.

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Cardiac resynchronization therapy (CRT) has shown the ability to reverse left ventricular remodeling in some patients. Early ... "20 Years of Cardiac Resynchronization Therapy". Journal of the American College of Cardiology. Elsevier BV. 64 (10): 1047-1058 ... "Long-Term Prognosis After Cardiac Resynchronization Therapy Is Related to the Extent of Left Ventricular Reverse Remodeling at ... Besides, the cardiac interstitium which consisted of largely Type I and Type III collagen fibres are also involved in cardiac ...
Cardiac resynchronization therapy (CRT) may be necessary. If other measures are not effective a heart transplant may be an ... Cardiac Myosin Binding Protein C (MYBPC3), Myosin Heavy Chain 7 (MYH7), Cardiac Troponin T 2 (TNNT2), and Cardiac Troponin I ( ... and cardiac testing to screen for early findings of dilated cardiomyopathy. Cardiac magnetic resonance imaging (cardiac MRI) ... Drug therapy can slow down progression and in some cases even improve the heart condition. Standard therapy may include salt ...
He contributed to Clinical Cardiac Pacing, Defibrillation and Resynchronization Therapy. "Frits Prinzen , Radcliffe Cardiology ... Prinzen works on cardiac pacing therapies, both for bradycardia and for heart failure (cardiac resynchronisation therapy, CRT ... Prinzen is an expert on cardiac pacing therapies, both for bradycardia and for heart failure (cardiac resynchronisation therapy ... Clinical Cardiac Pacing, Defibrillation and Resynchronization Therapy , ScienceDirect. ISBN 9780323378048. Overview at peer ...
Applications include atrial fibrillation and cardiac resynchronization therapy. Pre-operative MRI or CT is used to plan the ... In cardiac surgery, shared control systems can perform mitral valve replacement or ventricular pacing by small thoracotomies. ...
In addition, this approach has been applied in cardiac resynchronization therapy (CRT) as a new biological pacemaker as a ... Nussinovitch U, Gepstein L (July 2015). "Optogenetics for in vivo cardiac pacing and resynchronization therapies". Nature ... Zimmer C (24 May 2021). "Scientists Partially Restored a Blind Man's Sight With New Gene Therapy". The New York Times. ... A recent study explored the possibilities of optogenetics as a method to correct for arrythmias and resynchronize cardiac ...
"Registration with Adjacent Anatomical Structures for Cardiac Resynchronization Therapy Guidance". Statistical Atlases and ... However, over the last few years, there has been a growing interest in the predictive assessment of disease or therapy course. ... Image-based patient-specific modelling, combined with models of medical devices and pharmacological therapies, opens the way to ...
"Cardiac-Resynchronization Therapy for the Prevention of Heart-Failure Events". New England Journal of Medicine. 361 (14): 1329- ... Stafford, Ned (2018). "Arthur J Moss: pioneered clinical research into long QT syndrome and sudden cardiac death". BMJ: k1457. ... "Arthur Moss Receives Heart Rhythm Society's Pioneer in Cardiac Pacing and EP Award". URMC Newsroom. May 12, 2017. "URMC ... Glorney-Raisbeck Award in Cardiology, New York Academy of Medicine, 2008 Golden Lionel Award, Venice International Cardiac ...
"Building a pipeline for in-silico modelling of cardiac resynchronization therapy". vph-noe. p. 11. Archived from the original ... from medical images to characterization and quantification of myocardial diseases and Cardiac Resynchronization Therapy (CRT) ... "Advance Tool for Visualization of Multi-modal and Multi-scale Cardiac Data" (PDF). UPF. p. 42. Archived from the original (PDF ... Gimias has been used to develop clinical prototypes in the fields of cardiac imaging and simulation, angiography imaging and ...
Cardiac resynchronization therapy (CRT) is used for people with heart failure in whom the left and right ventricles do not ... Ganjehei L, Razavi M, Massumi A (2011). "Cardiac resynchronization therapy: a decade of experience and the dilemma of ... Ramsdale, David R. (2012). Cardiac pacing and device therapy. Rao, Archana. London: Springer. ISBN 978-1-4471-2939-4. OCLC ... "The effect of cardiac resynchronization on morbidity and mortality in heart failure" (PDF). N. Engl. J. Med. 352 (15): 1539-49 ...
10 October 2013). "Cardiac-Resynchronization Therapy in Heart Failure with a Narrow QRS Complex" (PDF). N Engl J Med. 369 (15 ... Cardiac Resynchronization-Heart Failure (CARE-HF) Study Investigators. (2005). "The effect of cardiac resynchronization on ... 2004). "Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure". N ... or less and a QRS interval of 120 ms or more may benefit from cardiac resynchronization therapy (CRT; pacing both the left and ...
In some moderate or more severe cases, cardiac resynchronization therapy (CRT) or cardiac contractility modulation may be ... October 2013). "Cardiac-resynchronization therapy in heart failure with a narrow QRS complex" (PDF). The New England Journal of ... or cardiac resynchronization therapy. Echocardiography can also help determine if acute myocardial ischemia is the ... December 2004). "Drug therapy in the heart transplant recipient: part I: cardiac rejection and immunosuppressive drugs". ...
"Cardiac Contractility Modulation in Non-responders to Cardiac Resynchronization Therapy". Europace. 10 (12): 1375-1380. doi: ... In cardiac contractility modulation therapy, electrical stimulation is applied to the cardiac muscle during the absolute ... Artificial cardiac pacemaker Implantable cardioverter-defibrillator NYHA classification Cardiac resynchronization therapy ... Cardiac resynchronization therapy (CRT; also known as biventricular pacing) has proven to be an effective treatment in heart ...
Recent studies suggest that cardiac resynchronization therapy can reduce the incidence of ventricular dyssynchrony and thus ... "Review - The Pathology of Ventricular Dyssynchrony and the Role of Cardiac Resynchronization Therapy". Medscape. Retrieved 13 ... Large differences in timing of contractions can reduce cardiac efficiency and is correlated with heart failure. Three chief ... All articles with unsourced statements, Articles with unsourced statements from February 2021, Cardiac arrhythmia). ...
... therapy in South Asia. He is also credited with the introduction of Cardiac Resynchronization Therapy in India. He is a ... Implantable cardioverter-defibrillator Cardiac Resynchronization Therapy India portal Medicine portal "K.K. Talwar on WHFS". ... In 2000, he brought the Cardiac Resynchronization Therapy to India for the first time. The introduction of multisite pacing ... His work on Cardiac arrhythmia helped develop it as a specialty in India and he was associated with Heart transplant program at ...
Relation of cardiac output to QRS duration during temporary resynchronization therapy after cardiac surgery. ASAIO J. 2010; ... also known as cardiac resynchronization therapy), which involves installation of pacemakers to fix delays in heart ventricle ... Cardiac output measurement by arterial pressure waveform analysis during optimization of biventricular pacing after cardiac ... Surgical Considerations of Pacemakers and Automatic Defibrillators, in Cohn L, Cardiac Surgery in the Adult. Spotnitz HM. 2nd ...
... with a cardiac resynchronization therapy device". Journal of Zoo and Wildlife Medicine. 42 (2): 263-276. doi:10.1638/2009- ... "Surgical implantation of a cardiac resynchronization therapy device in a western lowland gorilla (Gorilla gorilla gorilla) with ... Heart disease was the cause of 16 of the 52 deaths at Yakex primate research center between 1992 and 2005, and cardiac biopsies ... The gorilla's heart fibrosis has been distributed in an unorderly manner in the cardiac muscle as seen in human.[citation ...
February 2012). "Indications for cardiac resynchronization therapy: 2011 update from the Heart Failure Society of America ... Guideline Committee". Journal of Cardiac Failure. 18 (2): 94-106. doi:10.1016/j.cardfail.2011.12.004. PMID 22300776. (Articles ... stenosis Dilated cardiomyopathy Acute myocardial infarction Extensive coronary artery disease Primary disease of the cardiac ...
... therapy is used to reduce the symptoms of heart failure in patients who do not qualify for cardiac resynchronization therapy. ... Baroreflex activation therapy is an approach to treating high blood pressure and the symptoms of heart failure. It uses an ... Gordin, D; Vikatmaa, P; Vikatmaa, L; Groop, PH; Albäck, A; Tikkanen, I (2016). "Baroreflex activation therapy in the treatment ... Scheffers, IJ; Kroon, AA; Tordoir, JH; de Leeuw, PW (January 2008). "Rheos Baroreflex Hypertension Therapy System to treat ...
"What Is a Cardiac Resynchronization Therapy Device?". Medtronic. "U.S. Supreme Court tosses out Medtronic pacemaker patent loss ... which dealt with cardiac resynchronization therapy, a pacemaker that is used to treat congestive heart failure. Medtronic ...
On September 25, 2004, Babec became the first gorilla to undergo the successful implant of a cardiac resynchronization therapy ...
... an enzyme Cardiac resynchronization therapy pacemaker This disambiguation page lists articles associated with the title CRTP. ...
... and cardiac resynchronization therapy to prevent sudden cardiac death. However, in view of reversible cardiomyopathy, sometimes ... or Cardiac resynchronization therapy (CRT) are not routinely used and reserved for severe LV dysfunction or high risk cases. ... Antiviral therapy, immunoabsorption, intravenous gamma globulin, or other immunomodulation therapy may then be considered ... Further testing can also include a chest x-ray, brain natriuretic peptide levels, EKG, echocardiogram, cardiac MRI, and cardiac ...
... its 2019 remake Cardiac resynchronization therapy Cardio-thoracic ratio, a measure of the size of heart Carpal tunnel release, ...
... for blood to refill capillaries Cardiac resynchronization therapy and CRT defibrillator (CRT-D) Catheter-related thrombosis, ... and radiotherapy combined Cognitive Retention Therapy, for dementia Corneal Refractive Therapy, in optometrics CRT (genetics), ...
Simple regional strain pattern analysis to predict response to cardiac resynchronization therapy: rationale, initial results, ... additional echo criteria for selection of Heart failure patients with LBBB who may respond to Cardiac resynchronization therapy ... Movements of the base of the ventricle and relative constancy of the cardiac volume. Am J Physiol 1932;102:559-65. Hoffman EA, ... It has an advantage over Ejection fraction (EF), it shows reduced cardiac function also in hypertrophic hearts with small ...
... cardiac resynchronization therapy, and leadless pacemaker technology. 2004: Canadian Medical Association Award for Young ... followed by a Heart and Stroke Foundation Fellowship in cardiac electrophysiology at the University of Western Ontario in 1999 ... of Policy Studies at Queen's University and completed a 10-year term as Chief of Cardiology and medical director of the Cardiac ...
Cardiac Resynchronization Therapy Cathode Ray Tube Chinese Remainder Theorem CRTC - (i) Canadian Radio-television and ... Cognitive Behaviour Therapy (p) Combat CBUS - (i) Columbus, Ohio CC - many, including carbon copy; see entry CCA - (i) Counter ... Cardiac Rhythm Management - Customer Relationship Management CRO - (s) Croatia (IOC and FIFA trigram, but not ISO 3166) - ...
... cardiac resynchronization therapy (CRT), laser lead extraction and ablation of atrial fibrillation and ventricular tachycardia ... "precise electrical measurements at the tip of a cardiac catheter, providing cardiac specialists with both numbers and a visual ... He has published research into complex ablation and pioneered cardiac ablation methods. Khaykin attended the University of ... 2009). "Cost Comparison of Ablation Versus Antiarrhythmic Drugs As First-Line Therapy for Atrial Fibrillation: An Economic ...
... therapy brachytherapy cardiac resynchronization therapy cell therapy cytotherapy cell transfer therapy chelation therapy ... therapy lithium therapy low level laser therapy maggot therapy magnet therapy magnetic resonance therapy maintenance therapy ... therapy oral rehydration therapy osmotherapy oxygen therapy ozone therapy palliative therapy particle therapy pet therapy phage ... therapy protein therapy proton therapy pulsed electromagnetic field therapy PUVA therapy qigong therapy quack therapies ...
Cardiac resynchronisation therapy (CRT or CRT-P) is the insertion of electrodes in the left and right ventricles of the heart, ... a cardiac abnormality leading to delayed left ventricular contraction. LBBB causes a QRS prolongation of ≥120 ms on the ...
... which regulate cardiac processes involved in cardiac apoptosis, cardiac fibrosis, cardiac hypertrophy and angiogenesis, and ... the cardiac resynchronization therapy with a defibrillator (CRT) is the treatment of choice to improve symptoms, NYHA class, ... In patients under optimal medical therapy with moderate to severe HF and cardiac dyssynchrony, cardiac resynchronization ... "Cardiac resynchronization therapy reduces the risk of cardiac events in patients with diabetes enrolled in the multicenter ...
Uptake of this therapy proved to be low in this nationwide study and CRT implantation was largely used in patients with a pre … ... Background: Cardiac resynchronization therapy (CRT) is an established option for patients with heart failure. Limited data ... Cardiac resynchronization therapy in congenital heart disease: Results from the German National Register for Congenital Heart ... Keywords: Adult congenital heart disease; Cardiac resynchronisation; Congenital heart disease; Heart failure; Pacemaker therapy ...
Cardiac Resynchronization Therapy Systems Market. Cardiac Resynchronization Therapy Systems Market (Product - Cardiac ... Resynchronization Therapy Pacemaker, Cardiac Resynchronization Therapy Defibrillator) - Global Industry Analysis, Size, Share, ...
Cardiac resynchronization therapy complications ‎ (← links). *Cardiac resynchronization therapy special populations ‎ (← links) ... Cardiac resynchronization therapy preoperative evaluation ‎ (← links). *Cardiac resynchronization therapy recovery ‎ (← links) ... Cardiac resynchronization therapy landmark trials ‎ (← links). *Cardiac resynchronization therapy special populations ‎ (← ... Cardiac resynchronization therapy contraindications ‎ (← links). *Cardiac resynchronization therapy pathophysiology ‎ (← links) ...
Posts Tagged cardiac resynchronization therapy. RSS. April 24th, 2013. BLOCK HF: CRT Superior to Conventional Pacing in Heart ... Tags: cardiac resynchronization therapy, defibrillation, left bundle branch block, pacemakers. February 14th, 2011. CRT Found ... Tags: AV block, biventricular pacing, cardiac resynchronization therapy, CRT. March 27th, 2013. Left to Our Many Devices, Which ... Cardiac resynchronization therapy (CRT) appears to be beneficial in patients with less severe heart failure (NYHA class I and ...
CASE 10-2015: Cardiac Resynchronization Therapy: Role of Intraoperative Real-Time Three-Dimensional Transesophageal ... 2 In the past decade, cardiac resynchronization therapy (CRT), achieved by simultaneous LV and right ventricular (RV) pacing, ... Keywords : aortic valve stenosis, cardiac resynchronization therapy, heart failure, left bundle-branch block, QLab software, ... HomePublicationsCASE 10-2015: Cardiac Resynchronization Therapy: Role of Intraoperative Real-Time Three-Dimensional ...
Cardiac Resynchronization Therapy Market size is projected to reach $11.5 Bn by 2030, growing at a CAGR of 7.3% From 2022 To ... 5.2 Cardiac Resynchronization Therapy Defibrillators. 5.3 Cardiac Resynchronization Therapy Pacemakers. 6 GLOBAL CARDIAC ... Global Cardiac Resynchronization Therapy Market Size By Product (Cardiac Resynchronization Therapy Defibrillators, Cardiac ... Cardiac Resynchronization Therapy Market, By Product. • Cardiac Resynchronization Therapy Defibrillators. • Cardiac ...
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Background: Patients with heart failure and left bundle branch block (LBBB) may receive cardiac resynchronization therapy (CRT ... Background: Patients with heart failure and left bundle branch block (LBBB) may receive cardiac resynchronization therapy (CRT ... may receive cardiac resynchronization therapy (CRT), but current selection criteria are imprecise, and many patients have ... Cardiac and Cardiovascular Systems. keywords. Cardiac magnetic resonance, Device response, Heart failure with reduced ejection ...
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Cardiac Resynchronization Therapy (CRT) - Explore from the MSD Manuals - Medical Professional Version. ... Cardiac resynchronization therapy (CRT) involves use of a cardiac pacing system Cardiac Pacemakers The need for treatment of ... and a special form of pacing, cardiac resynchronization therapy), catheter ablation Ablation for Cardiac Arrhythmia The need ... Cardiac Resynchronization Therapy (CRT) By L. Brent Mitchell , MD, Libin Cardiovascular Institute of Alberta, University of ...
Does cardiac resynchronization therapy restore peripheral circulatory homeostasis? ESC Heart Failure. 2018 Feb;5(1):129-138. ... Does cardiac resynchronization therapy restore peripheral circulatory homeostasis?. Chukwudiebube N. Ajaero, Cher-Rin Chong, ... Does cardiac resynchronization therapy restore peripheral circulatory homeostasis? / Ajaero, Chukwudiebube N.; Chong, Cher-Rin ... title = "Does cardiac resynchronization therapy restore peripheral circulatory homeostasis?",. abstract = "Aims: To evaluate ...
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CRTd patients with diabetes that did not receive GLP-1 RA therapy, experienced a significant reduction of NYHA class (p value & ... a matched cohort of CRTd patients with diabetes treated with GLP-1 RA in addition to conventional hypoglycemic therapy (n 288 ... We investigated the 12-months prognosis of CRTd patients with diabetes, previously treated with hypoglycemic drugs therapy (n ... Consequently, GLP-1 RA drugs in addition to conventional hypoglycemic therapy may reduce hospital admissions for heart failure ...
Cardiac resynchronization therapy (CRT) is a treatment to help your heart beat with the right rhythm. It uses a pacemaker to re ... Cardiac resynchronization therapy (CRT) is a treatment to help your heart beat with the right rhythm. It uses a pacemaker to re ...
... BORIANI, GIUSEPPE;Biffi M;MARTIGNANI, CRISTIAN; ... on the relationship between electrical and structural reverse remodeling in patients treated with cardiac resynchronization ... on the relationship between electrical and structural reverse remodeling in patients treated with cardiac resynchronization ... A period of pacing-induced resynchronization appears to accentuate the potential for RV pacing-driven electrical ...
Cardiac resynchronization therapy involves implanting a device in the chest to arrange and efficiently cause the hearts ... Who Needs Cardiac Resynchronization Therapy?. A pacemaker or cardiac resynchronization therapy may be required in cases of ... cardiac resynchronization therapy has different risks for different people.. Cardiac resynchronization therapy and implantation ... Advantages of Cardiac Resynchronization Therapy -Best Cardiologist in Indore. The advantages of Cardiac resynchronization ...
Electrophysiology Procedures Cardiac resynchronization therapy What happens during a cardiac resynchronization therapy? Print ... Normally, you can expect the following during a cardiac resynchronization therapy -. *You are made to lie on the procedure ... Cardiac Resynchronization Therapy. (n.d.). Retrieved from https://www.azheartarrhythmia.com/contents/ep-procedures/cardiac- ...
Access this presentation on ESC 365 from ESC Congress 2016 on Resynchronisation therapy by Associate Professor A. Schmidt ( ... Cardiac resynchronization therapy in chronic chagasic cardiomyopathy. A seven-year experience at a university hospital.. ... Cardiac resynchronization therapy combined with coronary artery bypass grafting in ischemic heart failure patients: long-term ... Role of ventricular lead position in response to cardiac resynchronization therapy: non-invasive electrophysiological mapping ...
Cardiac Resynchronization Therapy (CRT) - Explore from the MSD Manuals - Medical Professional Version. ... Cardiac resynchronization therapy (CRT) involves use of a cardiac pacing system Cardiac Pacemakers The need for treatment of ... and a special form of pacing, cardiac resynchronization therapy), catheter ablation Ablation for Cardiac Arrhythmia The need ... Cardiac Resynchronization Therapy (CRT) By L. Brent Mitchell , MD, Libin Cardiovascular Institute of Alberta, University of ...
a Cardiac Resynchronization Therapy Pacemaker (CRT-P) or. ✓ a Cardiac Resynchronization Therapy Defibrillator (CRT-D) may be ...
Cardiac Resynchronization Therapy (CRT). Some people with heart failure develop abnormal heart beats, called arrhythmias. This ... Cardiac resynchronization therapy, also known as biventricular pacing, may be needed. In this procedure, a special pacemaker ... Learn more about cardiac resynchronization therapy.. Left ventricular assist device (LVAD). The left ventricle is the large, ... The procedure is usually performed in the cardiac catheterization lab. A small tube (catheter) with a tiny, deflated balloon on ...
Gorcsan J, Kagiyama N. Can global longitudinal strain predict response to cardiac resynchronization therapy? Heart Rhythm. 2018 ... Gorcsan, J., & Kagiyama, N. (2018). Can global longitudinal strain predict response to cardiac resynchronization therapy? Heart ... Gorcsan, J & Kagiyama, N 2018, Can global longitudinal strain predict response to cardiac resynchronization therapy?, Heart ... Can global longitudinal strain predict response to cardiac resynchronization therapy? / Gorcsan, John; Kagiyama, Nobuyuki. In: ...
Cardiac Resynchronization Therapy - CRT) to ProKardia medical center in Pavia. Book your visit now! ... Cardiac Resynchronization Therapy - CRT). Cardiac resynchronization therapy (CRT) is a treatment option for heart failure and ... Follow-up and programming of biventricular ICD/Pacemaker (Cardiac Resynchronization Therapy - CRT) has no contraindications. ... Follow-up and programming of biventricular ICD/Pacemaker (Cardiac Resynchronization Therapy - CRT) has no risks. ...
... or QRS narrowing as predictor of response to cardiac resynchronization therapy (CRT) in order to reduce non-responders. However ... Baseline clinical variables, echocardiographic parameters and pharmacological therapies were included. QRS duration before and ...
... shares the results from the Left Bundle Branch Pacing for Cardiac ... LBBP As A Novel Strategy For Cardiac Resynchronization Therapy ... Arrhythmia AcademyinnovationsHRS 2020: LBBP As A Novel Strategy For Cardiac Resynchronization Therapy ... shares the results from the Left Bundle Branch Pacing for Cardiac Resynchronization Therapy study. ...
Learn more about the uses and different types of cardiac devices from the doctors at the Cleveland Clinic Heart & Vascular ... Cardiac Resynchronization Therapy (Biventricular Pacing). Cardiac resynchronization therapy (CRT) helps the ventricles contract ... Cardiac resynchronization therapy helps improve survival, quality of life, heart function and your ability to exercise, and can ... What is a cardiac device?. A cardiac device is used to keep your heart beating with a normal rhythm. There are several types of ...
  • Cardiac resynchronisation therapy (CRT or CRT-P) is the insertion of electrodes in the left and right ventricles of the heart, as well as on occasion the right atrium, to treat heart failure by coordinating the function of the left and right ventricles via a pacemaker, a small device inserted into the anterior chest wall. (wikipedia.org)
  • CRT with pacemaker only is often termed "CRT-P" to help distinguish it from CRT with defibrillator (CRT-D). The key indication for CRT is left bundle branch block (LBBB) of the heart, a cardiac abnormality leading to delayed left ventricular contraction. (wikipedia.org)
  • Pacemaker therapy. (nih.gov)
  • A cardiac resynchronization treatment pacemaker and a cardiac resynchronization therapy defibrillator are two types of cardiac resynchronization therapy devices. (verifiedmarketresearch.com)
  • Pacemaker technology has progressed into cardiac resynchronization treatment devices. (verifiedmarketresearch.com)
  • A pacemaker or cardiac resynchronization therapy may be required in cases of arrhythmia, or irregular heart rhythm. (cardiologistindore.in)
  • Depending on your heart failure condition, ✓ a Cardiac Resynchronization Therapy Pacemaker (CRT-P) or ✓ a Cardiac Resynchronization Therapy Defibrillator (CRT-D) may be indicated. (drpraveenchandra.com)
  • A pacemaker also is called a cardiac pacing device. (mayoclinic.org)
  • This type also is called a cardiac resynchronization pacemaker. (mayoclinic.org)
  • In patients under optimal medical therapy with moderate to severe HF and cardiac dyssynchrony, cardiac resynchronization therapy (CRT) with a defibrillator improves contractile function and reverse ventricular remodeling, ameliorating symptoms, quality of life (QoL), and clinical outcomes [ 7 , 8 ]. (hindawi.com)
  • Intraventricular dyssynchrony, interventricular dyssynchrony, and atrioventricular dyssynchrony are all treated using cardiac resynchronization treatment. (verifiedmarketresearch.com)
  • Magnetic resonance imaging assessment of intraventricular dyssynchrony and delayed enhancement as predictors of response to cardiac resynchronization therapy in patients with heart failure of ischaemic and non-ischaemic etiologies. (insa-lyon.fr)
  • Cardiac dyssynchrony can be suspected based on electrocardiogram (ECG) parameters (eg, left bundle branch block) and advanced echocardiography techniques (eg, tissue Doppler index, strain rate). (msdmanuals.com)
  • The widening of QRS observed during right ventricular (RV) pacing was greater after 3 months of BiV pacing (with respect to acute assessments), suggesting accentuation of pacing-induced electrical dyssynchrony after a period of pacing-induced resynchronization. (unicampus.it)
  • However, the impact of LV dilatation on the association of measures of dyssynchrony with long-term prognosis and resynchronization potential after cardiac resynchronization therapy (CRT) remains unclear. (psu.edu)
  • Cardiac resynchronization therapy (CRT) is the preferred treatment method for patients with ventricular dyssynchrony accompanied by reduced ejection fraction and bundle branch block [ 1 ]. (biomedcentral.com)
  • We show that the presence of left ventricular dyssynchrony and optimal lead location are linked to patient response to cardiac resynchronization therapy (CRT). (gitlab.io)
  • Cardiac resynchronization therapy or biventricular pacing is a small device that sends electrical impulses to lower chambers of the heart, helping them to beat together in a more synchronized pattern. (verifiedmarketresearch.com)
  • Biventricular pacemakers, also known as cardiac resynchronization devices, and are used in cardiac resynchronization therapy (CRT) to provide electrical signals to both of the heart's bottom chambers (right and left ventricles). (cardiologistindore.in)
  • Cardiac resynchronization therapy, also known as biventricular pacing, may be needed. (heart.org)
  • Uptake of this therapy proved to be low in this nationwide study and CRT implantation was largely used in patients with a pre-existing pacing indication or those requiring an ICD. (nih.gov)
  • 2 In the past decade, cardiac resynchronization therapy (CRT), achieved by simultaneous LV and right ventricular (RV) pacing, has emerged as a potent therapeutic option that improves the quality of life and functional status of patients with congestive heart failure, as well as prolongs survival. (amrita.edu)
  • It is widely used for patients with left bundle branch block, a condition that causes heart failure, as well as for those whose low heart rates make cardiac pacing likely to be necessary. (cardiologistindore.in)
  • Dr Pugazhendhi Vijayaraman (Geisinger Heart Institute, Mountain Top, PA, US) shares the results from the Left Bundle Branch Pacing for Cardiac Resynchronization Therapy study. (arrhythmiaacademy.com)
  • Purpose: Multisite cardiac resynchronization therapy (MSCRT) with dual-vein left ventricular (LV) pacing has theoretical advantages over conventional CRT in faster and more physiological LV activation. (bgu.ac.il)
  • Indianapolis, IN and St Paul, MN - The data and safety monitoring board of the Comparison of Medical Therapy, Pacing, and Defibrillation in Chronic Heart Failure (COMPANION) trial terminated the trial when it achieved its primary end point, a significant reduction in all-cause mortality and hospitalization. (medscape.com)
  • Since we published our previous Special Issue ( https://www.mdpi.com/journal/jcm/special_issues/Cardiac_Resynchronization_Therapy ), cardiac conduction system (CSP) pacing has evolved as an alternative to CRT. (mdpi.com)
  • Eighteen patients undergoing CRT upgrade with existing pacing systems underwent preimplant electrocardiogram-gated cardiac CT to assess wall thickness, hypoperfusion, late mechanical activation, and regions of myocardial scar by the derivation of the stretch quantifier for endocardial engraved zones (SQUEEZ) algorithm. (ucsd.edu)
  • Cardiac resynchronization therapy with physiological left bundle branch pacing as a treatment for arrhythmogenic cardiomyopathy with left ventricle involvement: a new therapeutic approach? (mdpub.net)
  • Cardiac Pacemakers The need for treatment of arrhythmias depends on the symptoms and the seriousness of the arrhythmia. (msdmanuals.com)
  • These trials set the stage for MADIT-CRT and the evaluation of defibrillators with resynchronization therapy in lower-risk patients. (rochester.edu)
  • Cardiac resynchronization therapy and implantable cardiac defibrillators in left ventricular systolic dysfunction. (wustl.edu)
  • OBJECTIVES: To determine the efficacy, effectiveness, and safety of cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillators (ICD) in patients with left ventricular systolic dysfunction (LVSD). (wustl.edu)
  • In fact, in the Multicenter Automatic Defibrillator Implantation Trial with CRT (MADIT-CRT) and the Cardiac Resynchronization-HF (CARE-HF), the mean age of enrolled patients was 65 and 66.4, respectively [ 11 , 12 ]. (hindawi.com)
  • New sections on cardiac anatomy and physiology and imaging of the heart, a new online chapter covering radiography of devices, and thought-provoking new information on the basic science of device implantation. (elsevier.ca)
  • Purpose: To describe what knowledge heart failure patients expect to acquire in relation to their upcoming cardiac resynchronization therapy (CRT) device implantation, to describe their self-care and health complaints, and to explore the relationship between knowledge expectations and self-care, health complaints, and background factors. (edu.au)
  • There are various benefits associated with cardiac resynchronization therapy system, as it improves heart efficiency, increases blood flow and improves quality of life. (verifiedmarketresearch.com)
  • Cardiac resynchronization therapy improves cardiac performance and myocardial mechanical efficiency. (elsevierpure.com)
  • This week, Moss presented clinical data from the MADIT-CRT study at a meeting of the FDA's Circulatory System Devices panel showing that the combination of an implanted cardiac defibrillator, which detects irregular and potentially fatal heart rhythms and shocks the heart back into a normal rhythm, with cardiac resynchronization therapy, which improves the mechanical pumping action of the heart, provides preventive benefit to patients with more mild cardiac disease. (rochester.edu)
  • To evaluate clinical outcomes in patients with diabetes, treated by cardiac resynchronization therapy with a defibrillator (CRT-d), and glucagon-like peptide 1 receptor agonists (GLP-1 RA) in addition to conventional hypoglycemic therapy vs. CRTd patients under conventional hypoglycemic drugs. (biomedcentral.com)
  • Application of strain and other echocardiographic parameters in the evaluation of early and long-term clinical outcomes after cardiac surgery revascularization. (crossref.org)
  • The purpose of this study was to evaluate cardiac computed tomography (CT) selection of the optimal epicardial vein for left ventricular (LV) lead placement by targeting regions of late mechanical activation and avoiding myocardial scar. (ucsd.edu)
  • Left ventricular wall thickness measured with computed tomography stratifies the response to cardiac resynchronization therapy in patients with non-ischemic cardiomyopathy. (escardio.org)
  • Cardiac venous anatomy was mapped to individualized American Heart Association (AHA) bull's-eye plots to identify the optimal venous target and compared with acute hemodynamic response (AHR) in each coronary venous target using an LV pressure wire. (ucsd.edu)
  • Background: Before performing cardiac resynchronization therapy (CRT), it is useful to visualize the position of the coronary sinus (CS) orifice where the CS lead is inserted. (elsevierpure.com)
  • Subject has an indication for coronary angiography or left heart catheterization or cardiac resynchronization therapy. (who.int)
  • abstract = "Aims: To evaluate whether peripheral circulatory {\textquoteleft}remodeling{\textquoteright} as measured by changes in vascular compliance and in markers of nitric oxide signaling contributes to patient response to cardiac resynchronization therapy (CRT) Methods and results: Effects of CRT were evaluated in 33 patients pre- and 6 months post- procedure. (uea.ac.uk)
  • Can global longitudinal strain predict response to cardiac resynchronization therapy? (psu.edu)
  • In this trial [ 23 ] the role of diabetes mellitus has been analyzed as predictor of appropriate/inappropriate internal defibrillator therapy. (hindawi.com)
  • Patients in the trial were randomized to 1 of 3 arms: optimal medical therapy, resynchronization therapy with the Guidant Corp CONTAK TR® device, or resynchronization/defibrillator therapy with Guidant's CONTAK CD® device. (medscape.com)
  • In the major study which tested the device - the MADIT-CRT trial - patients who had a cardiac resynchronization device combined with a defibrillator (CRT-D) implanted had a 34 percent reduction in their risk of death or heart failure compared to patients receiving only an implantable cardioverter defibrillator (ICD) . (rochester.edu)
  • In summary, this new textbook is a comprehensive source of current information regarding CIEDs for trainees and practitioners, whether they are clinicians or researchers in the field of clinical cardiac electrophysiology. (elsevier.ca)
  • Expert guidance from world authorities who contribute fresh perspectives on the challenging clinical area of cardiac electrophysiology. (elsevier.ca)
  • Baseline clinical variables, echocardiographic parameters and pharmacological therapies were included. (anmco.it)
  • The result of a 10-year clinical science program, the SonR sensor uniquely measures patient's cardiac muscle vibrations. (medlatest.com)
  • Transition of CSP to first-line therapy instead of CRT is awaiting landmark trials, but implementation in real-life clinical settings has already progressed. (mdpi.com)
  • Background: Patients with heart failure and left bundle branch block (LBBB) may receive cardiac resynchronization therapy (CRT), but current selection criteria are imprecise, and many patients have limited treatment response. (lu.se)
  • In this updated critical appraisal we report on the main miRs that play a key role in response to cardiac resynchronization therapy (i.e., responder vs nonresponder HF patients), focusing on the miR-mediated modulation of cardiac angiogenesis, apoptosis, fibrosis and membrane ionic currents. (elsevierpure.com)
  • BACKGROUND: Several studies have evaluated the role of QRS duration (QRSd) or QRS narrowing as predictor of response to cardiac resynchronization therapy (CRT) in order to reduce non-responders. (anmco.it)
  • Optimal lead positioning is an important determinant of cardiac resynchronization therapy (CRT) response. (ucsd.edu)
  • Given the important roles that biochemical markers such as extracellular matrix proteins and inflammatory signals can play in cardiac tissue remodeling, Spinale and colleagues recently showed that the circulating levels of several serum protein biomarkers can hold exciting predictive capability for CRT response [ 15 ]. (biomedcentral.com)
  • [ 10 ] and also of response to cardiac resynchronization therapy. (medscape.com)
  • For instance, in 2017, Resonate Cardiac Resynchronization Therapy defibrillator (CRT-D) systems were launched by Boston Scientific in Europe. (verifiedmarketresearch.com)
  • Background: Cardiac resynchronization therapy (CRT) has been shown to reduce heart failure-related morbidity and mortality. (hacettepe.edu.tr)
  • There was also a significant reduction in mortality in patients who received the resynchronization and ICD combination devices. (medscape.com)
  • Bristow and Feldman reported a statistically significant 20% reduction in all-cause mortality and all-cause hospitalization in both groups who received the devices compared with patients who received optimal medical therapy. (medscape.com)
  • In addition, there was a statistically significant 40% reduction in all-cause mortality in patients who received the resynchronization/defibrillator device. (medscape.com)
  • The mortality reduction in the resynchronization-alone arm was approximately half the reduction in the resynchronization/ICD arm. (medscape.com)
  • Cardiac resynchronization therapy (CRT) is an established technique to improve morbidity and mortality in selected heart failure patients. (mdpi.com)
  • Rationale: Cardiac resynchronization therapy (CRT) is the only heart failure (HF) therapy documented to improve left ventricular function and reduce mortality. (johnshopkins.edu)
  • A new therapy that reduces the risk of mortality and heart failure in patients with mild cardiac disease received a thumb's up this week from an advisory panel to the U.S. Food and Drug Administration. (rochester.edu)
  • Based on this trial, the 2016 American College of Cardiology/American Heart Association (ACC/AHA) focused update on new pharmacologic therapy for heart failure gives sacubitril-valsartan an IB-R indication for patients with heart failure with reduced ejection fraction to reduce morbidity and mortality. (medscape.com)
  • Cardiac resynchronization therapy (CRT) is a treatment option for heart failure and is performed using a subcutaneous device capable of stimulating different portions of the heart chambers, improving the mechanical efficiency of the heart pump. (prokardia.it)
  • Cardiac resynchronization therapy system comprises of two components, the pulse generator, or device and thin insulted wires also known as leads. (verifiedmarketresearch.com)
  • What is a cardiac device? (clevelandclinic.org)
  • A cardiac device is used to keep your heart beating with a normal rhythm. (clevelandclinic.org)
  • An implantable cardiac defibrillator (ICD) is an electronic device that is placed inside the body. (clevelandclinic.org)
  • The new device combines two functions found in current devices: an ICD, which is designed to prevent sudden cardiac death, and cardiac resynchronization therapy, which works to reduce heart failure and associated symptoms. (rochester.edu)
  • Cardiac Resynchronization Therapy (CRT) is a widely used, device-based therapy for patients with left ventricle (LV) failure. (biomedcentral.com)
  • The use of cardiac resynchronization therapy for the treatment of heart failure patients has resulted in a reduction in the number of deaths caused by sudden cardiac arrest in these individuals. (verifiedmarketresearch.com)
  • An ICD can help reduce your risk of sudden cardiac arrest (SCA). (clevelandclinic.org)
  • What is Sudden Cardiac Arrest (SCA)? (clevelandclinic.org)
  • Sudden cardiac arrest (SCA) is a sudden death that happens when the heart stops working because of an abnormal heart rhythm. (clevelandclinic.org)
  • Cardiac resynchronization therapy (CRT) is an established option for patients with heart failure. (nih.gov)
  • Patients with heart failure whose lower heart chambers (ventricles) don't contract in sync can receive treatment with cardiac resynchronization therapy. (cardiologistindore.in)
  • CRT effects are related to alterations in genes and microRNAs (miRs) expression, which regulate cardiac processes involved in cardiac apoptosis, cardiac fibrosis, cardiac hypertrophy and angiogenesis, and membrane channel ionic currents. (hindawi.com)
  • Heart failure (HF) disease progression is related to numerous adaptive processes including cardiac fibrosis, hypertrophy and apoptosis by activation of the 'fetal' gene program and downregulation of mRNA signatures, suggesting the importance of molecular mechanisms that suppress mRNA steady-state levels. (elsevierpure.com)
  • Your must-have bench reference for cardiac electrophysiology is now better than ever! (elsevier.ca)
  • Journal of Interventional Cardiac Electrophysiology , 51 (2), 143-152. (bgu.ac.il)
  • This is most likely due to impaired resynchronization efficacy. (psu.edu)
  • Efficacy and safety of cardiac resynchronization therapy in chemotherapy-induced cardiomyopathy: A systematic review. (bvsalud.org)
  • The aim of the study was to assess the efficacy of cardiac resynchronization therapy (CRT) in patients with chemotherapy -induced cardiomyopathy (CIC). (bvsalud.org)
  • The loss of myocytes leads to cardiac dilation and an increased afterload and wall tension, which results in further systolic dysfunction. (medscape.com)
  • Does cardiac resynchronization therapy restore peripheral circulatory homeostasis? (uea.ac.uk)
  • Horowitz, John D. / Does cardiac resynchronization therapy restore peripheral circulatory homeostasis? . (uea.ac.uk)
  • In selected patients affected by HF and severe dysfunction of left ventricle ejection fraction (LVEF), with left bundle brunch block, the cardiac resynchronization therapy with a defibrillator (CRT) is the treatment of choice to improve symptoms, NYHA class, and quality of life. (hindawi.com)
  • cardiac resynchronization therapy (CRT) has been restricted to patients with a low ejection fraction and a wide QRS duration. (jwatch.org)
  • In some patients, the normal, orderly, sequential relationship between contraction of the cardiac chambers is disrupted (becomes dyssynchronous). (msdmanuals.com)
  • CRT is a therapy that delivers timely electrical pulses to the chambers of the heart. (medlatest.com)
  • Cardiac resynchronization therapy in chronic chagasic cardiomyopathy. (escardio.org)
  • Cardiac resynchronization therapy may lessen the signs and symptoms of heart failure as well as the danger of fatal consequences. (cardiologistindore.in)
  • Computationally integrating general patient characteristics, comorbidities, therapy history, circulating biomarkers, and LV function data available before CRT intervention can improve the prediction of individual patient responses. (biomedcentral.com)
  • The cardiac resynchronization therapy system gadget operates by providing electrical signals to the heart muscle to resynchronize the contractions of the heart ventricles. (verifiedmarketresearch.com)
  • More information is required on the relationship between electrical and structural reverse remodeling in patients treated with cardiac resynchronization theraphy. (unicampus.it)
  • Studies have shown that around one-third of patients with advanced heart failure do not effectively respond to cardiac resynchronization therapy (CRT)4,5. (medlatest.com)
  • The panel's recommended approval of this therapy is great news for a large population of patients in which it could effectively prevent heart failure progression," said Moss. (rochester.edu)
  • CRT (cardiac resynchronization therapy) is a therapy that helps the heartbeat in the proper rhythm. (verifiedmarketresearch.com)
  • Cardiac resynchronization therapy (CRT) is a treatment to help your heart beat with the right rhythm. (patient9.com)
  • On the other side, lack of skilled personnel and limitation of the use of Cardiac Resynchronization Therapy in pediatric patients are the factors that might restrict the market growth. (verifiedmarketresearch.com)
  • Diminished cardiac output is caused by a complex interaction of various factors. (medscape.com)
  • The rising incidence of cardiovascular diseases globally is expected to boost the growth of the global Cardiac Resynchronization Therapy Market. (verifiedmarketresearch.com)