Ventricular Dysfunction, Left
A condition in which the LEFT VENTRICLE of the heart was functionally impaired. This condition usually leads to HEART FAILURE; MYOCARDIAL INFARCTION; and other cardiovascular complications. Diagnosis is made by measuring the diminished ejection fraction and a depressed level of motility of the left ventricular wall.
Ventricular Dysfunction, Right
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.
A condition in which HEART VENTRICLES exhibit impaired function.
Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.
The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.
A 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.
Ventricular Function, Left
Ventricular Function, Right
The hemodynamic and electrophysiological action of the right HEART VENTRICLE.
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).
Natriuretic Peptide, Brain
A PEPTIDE that is secreted by the BRAIN and the HEART ATRIA, stored mainly in cardiac ventricular MYOCARDIUM. It can cause NATRIURESIS; DIURESIS; VASODILATION; and inhibits secretion of RENIN and ALDOSTERONE. It improves heart function. It contains 32 AMINO ACIDS.
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.
Imaging of a ventricle of the heart after the injection of a radioactive contrast medium. The technique is less invasive than cardiac catheterization and is used to assess ventricular function.
Contractile activity of the MYOCARDIUM.
NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).
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.
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.
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.
Period of contraction of the HEART, especially of the HEART VENTRICLES.
Prolonged dysfunction of the myocardium after a brief episode of severe ischemia, with gradual return of contractile activity.
The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.
A catecholamine derivative with specificity for BETA-1 ADRENERGIC RECEPTORS. It is commonly used as a cardiotonic agent after CARDIAC SURGERY and during DOBUTAMINE STRESS ECHOCARDIOGRAPHY.
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).
Agents that have a strengthening effect on the heart or that can increase cardiac output. They may be CARDIAC GLYCOSIDES; SYMPATHOMIMETICS; or other drugs. They are used after MYOCARDIAL INFARCT; CARDIAC SURGICAL PROCEDURES; in SHOCK; or in congestive heart failure (HEART FAILURE).
Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.
Mitral Valve Insufficiency
Backflow of blood from the LEFT VENTRICLE into the LEFT ATRIUM due to imperfect closure of the MITRAL VALVE. This can lead to mitral valve regurgitation.
Predictive Value of Tests
In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.
Angiotensin-Converting Enzyme Inhibitors
A class of drugs whose main indications are the treatment of hypertension and heart failure. They exert their hemodynamic effect mainly by inhibiting the renin-angiotensin system. They also modulate sympathetic nervous system activity and increase prostaglandin synthesis. They cause mainly vasodilation and mild natriuresis without affecting heart rate and contractility.
Blocking of the PULMONARY ARTERY or one of its branches by an EMBOLUS.
An angiotensin-converting enzyme inhibitor that is used to treat HYPERTENSION and HEART FAILURE.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
Unstable isotopes of thallium that decay or disintegrate emitting radiation. Tl atoms with atomic weights 198-202, 204, and 206-210 are thallium radioisotopes.
Coronary Artery Bypass
Surgical therapy of ischemic coronary artery disease achieved by grafting a section of saphenous vein, internal mammary artery, or other substitute between the aorta and the obstructed coronary artery distal to the obstructive lesion.
An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.
Tomography, Emission-Computed, Single-Photon
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.
Disease Models, Animal
Pathological conditions involving the HEART including its structural and functional abnormalities.
Severity of Illness Index
Cardiac Output, Low
A state of subnormal or depressed cardiac output at rest or during stress. It is a characteristic of CARDIOVASCULAR DISEASES, including congenital, valvular, rheumatic, hypertensive, coronary, and cardiomyopathic. The serious form of low cardiac output is characterized by marked reduction in STROKE VOLUME, and systemic vasoconstriction resulting in cold, pale, and sometimes cyanotic extremities.
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.
Transposition of Great Vessels
A congenital cardiovascular malformation in which the AORTA arises entirely from the RIGHT VENTRICLE, and the PULMONARY ARTERY arises from the LEFT VENTRICLE. Consequently, the pulmonary and the systemic circulations are parallel and not sequential, so that the venous return from the peripheral circulation is re-circulated by the right ventricle via aorta to the systemic circulation without being oxygenated in the lungs. This is a potentially lethal form of heart disease in newborns and infants.
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)
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.
The circulation of blood through the CORONARY VESSELS of the HEART.
Cardiac Pacing, Artificial
Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.
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.
The restoration of blood supply to the myocardium. (From Dorland, 28th ed)
The chambers of the heart, to which the BLOOD returns from the circulation.
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.
Atrial Natriuretic Factor
A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.
Increased VASCULAR RESISTANCE in the PULMONARY CIRCULATION, usually secondary to HEART DISEASES or LUNG DISEASES.
Hypertrophy, Right Ventricular
Enlargement of the RIGHT VENTRICLE of the heart. This increase in ventricular mass is often attributed to PULMONARY HYPERTENSION and is a contributor to cardiovascular morbidity and mortality.
Heart Function Tests
Examinations used to diagnose and treat heart conditions.
Hypertrophy, Left Ventricular
Enlargement of the LEFT VENTRICLE of the heart. This increase in ventricular mass is attributed to sustained abnormal pressure or volume loads and is a contributor to cardiovascular morbidity and mortality.
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).
The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
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.
Aortic Valve Stenosis
A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Preexisting Condition Coverage
Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.
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.
Magnetic Resonance Imaging
The pressure within the CARDIAC ATRIUM. It can be measured directly by using a pressure catheter (see HEART CATHETERIZATION). It can be also estimated using various imaging techniques or other pressure readings such as PULMONARY CAPILLARY WEDGE PRESSURE (an estimate of left atrial pressure) and CENTRAL VENOUS PRESSURE (an estimate of right atrial pressure).
Sensitivity and Specificity
Radiography of the vascular system of the heart muscle after injection of a contrast medium.
Pulmonary Wedge Pressure
The blood pressure as recorded after wedging a CATHETER in a small PULMONARY ARTERY; believed to reflect the PRESSURE in the pulmonary CAPILLARIES.
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.
Death, Sudden, Cardiac
Unexpected rapid natural death due to cardiovascular collapse within one hour of initial symptoms. It is usually caused by the worsening of existing heart diseases. The sudden onset of symptoms, such as CHEST PAIN and CARDIAC ARRHYTHMIAS, particularly VENTRICULAR TACHYCARDIA, can lead to the loss of consciousness and cardiac arrest followed by biological death. (from Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 7th ed., 2005)
Analysis of Variance
The valve between the left atrium and left ventricle of the heart.
Coronary Artery Disease
Diversion of the flow of blood from the entrance of the right atrium directly to the aorta (or femoral artery) via an oxygenator thus bypassing both the heart and lungs.
Cardiac Surgical Procedures
Surgery performed on the heart.
Autonomic Nervous System Diseases
Diseases of the parasympathetic or sympathetic divisions of the AUTONOMIC NERVOUS SYSTEM; which has components located in the CENTRAL NERVOUS SYSTEM and PERIPHERAL NERVOUS SYSTEM. Autonomic dysfunction may be associated with HYPOTHALAMIC DISEASES; BRAIN STEM disorders; SPINAL CORD DISEASES; and PERIPHERAL NERVOUS SYSTEM DISEASES. Manifestations include impairments of vegetative functions including the maintenance of BLOOD PRESSURE; HEART RATE; pupil function; SWEATING; REPRODUCTIVE AND URINARY PHYSIOLOGY; and DIGESTION.
A condition characterized by the thickening of ENDOCARDIUM due to proliferation of fibrous and elastic tissue, usually in the left ventricle leading to impaired cardiac function (CARDIOMYOPATHY, RESTRICTIVE). It is most commonly seen in young children and rarely in adults. It is often associated with congenital heart anomalies (HEART DEFECTS CONGENITAL;) INFECTION; or gene mutation. Defects in the tafazzin protein, encoded by TAZ gene, result in a form of autosomal dominant familial endocardial fibroelastosis.
Intra-Aortic Balloon Pumping
Counterpulsation in which a pumping unit synchronized with the patient's electrocardiogram rapidly fills a balloon in the aorta with helium or carbon dioxide in early diastole and evacuates the balloon at the onset of systole. As the balloon inflates, it raises aortic diastolic pressure, and as it deflates, it lowers aortic systolic pressure. The result is a decrease in left ventricular work and increased myocardial and peripheral perfusion.
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).
Gated Blood-Pool Imaging
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).
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
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.
A method of recording heart motion and internal structures by combining ultrasonic imaging with exercise testing (EXERCISE TEST) or pharmacologic stress.
Inflammatory processes of the muscular walls of the heart (MYOCARDIUM) which result in injury to the cardiac muscle cells (MYOCYTES, CARDIAC). Manifestations range from subclinical to sudden death (DEATH, SUDDEN). Myocarditis in association with cardiac dysfunction is classified as inflammatory CARDIOMYOPATHY usually caused by INFECTION, autoimmune diseases, or responses to toxic substances. Myocarditis is also a common cause of DILATED CARDIOMYOPATHY and other cardiomyopathies.
Sexual Dysfunction, Physiological
Abnormally rapid heartbeat, usually with a HEART RATE above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia.
A positive inotropic cardiotonic agent with vasodilator properties. It inhibits cAMP phosphodiesterase type 3 activity in myocardium and vascular smooth muscle. Milrinone is a derivative of amrinone and has 20-30 times the inotropic potency of amrinone.
Technetium Tc 99m Sestamibi
A technetium imaging agent used to reveal blood-starved cardiac tissue during a heart attack.
The exercise capacity of an individual as measured by endurance (maximal exercise duration and/or maximal attained work load) during an EXERCISE TEST.
Echocardiography, Doppler, Color
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.
Heart Valve Prosthesis
A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.
Aortic Valve Insufficiency
Pathological condition characterized by the backflow of blood from the ASCENDING AORTA back into the LEFT VENTRICLE, leading to regurgitation. It is caused by diseases of the AORTIC VALVE or its surrounding tissue (aortic root).
A condition characterized by the thickening of the ventricular ENDOCARDIUM and subendocardium (MYOCARDIUM), seen mostly in children and young adults in the TROPICAL CLIMATE. The fibrous tissue extends from the apex toward and often involves the HEART VALVES causing restrictive blood flow into the respective ventricles (CARDIOMYOPATHY, RESTRICTIVE).
Impaired impulse conduction from HEART ATRIA to HEART VENTRICLES. AV block can mean delayed or completely blocked impulse conduction.
Technetium Tc 99m Pyrophosphate
A radionuclide imaging agent used primarily in scintigraphy or tomography of the heart to evaluate the extent of the necrotic myocardial process. It has also been used in noninvasive tests for the distribution of organ involvement in different types of amyloidosis and for the evaluation of muscle necrosis in the extremities.
Heart Valve Prosthesis Implantation
Surgical insertion of synthetic material to repair injured or diseased heart valves.
A disease of the CARDIAC MUSCLE developed subsequent to the initial protozoan infection by TRYPANOSOMA CRUZI. After infection, less than 10% develop acute illness such as MYOCARDITIS (mostly in children). The disease then enters a latent phase without clinical symptoms until about 20 years later. Myocardial symptoms of advanced CHAGAS DISEASE include conduction defects (HEART BLOCK) and CARDIOMEGALY.
The measurement of visualization by radiation of any organ after a radionuclide has been injected into its blood supply. It is used to diagnose heart, liver, lung, and other diseases and to measure the function of those organs, except renography, for which RADIOISOTOPE RENOGRAPHY is available.
Tetralogy of Fallot
A combination of congenital heart defects consisting of four key features including VENTRICULAR SEPTAL DEFECTS; PULMONARY STENOSIS; RIGHT VENTRICULAR HYPERTROPHY; and a dextro-positioned AORTA. In this condition, blood from both ventricles (oxygen-rich and oxygen-poor) is pumped into the body often causing CYANOSIS.
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 disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).
Sexual Dysfunctions, Psychological
Diabetes complications in which VENTRICULAR REMODELING in the absence of CORONARY ATHEROSCLEROSIS and hypertension results in cardiac dysfunctions, typically LEFT VENTRICULAR DYSFUNCTION. The changes also result in myocardial hypertrophy, myocardial necrosis and fibrosis, and collagen deposition due to impaired glucose tolerance.
Proportional Hazards Models
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.
The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.
Reproducibility of Results
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
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 guanidine analog with specific affinity for tissues of the sympathetic nervous system and related tumors. The radiolabeled forms are used as antineoplastic agents and radioactive imaging agents. (Merck Index, 12th ed) MIBG serves as a neuron-blocking agent which has a strong affinity for, and retention in, the adrenal medulla and also inhibits ADP-ribosyltransferase.
Recovery of Function
The blood pressure in the ARTERIES. It is commonly measured with a SPHYGMOMANOMETER on the upper arm which represents the arterial pressure in the BRACHIAL ARTERY.
Tricuspid Valve Insufficiency
The veins and arteries of the HEART.
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.
Cardiac Resynchronization Therapy
The restoration of the sequential order of contraction and relaxation of the HEART ATRIA and HEART VENTRICLES by atrio-biventricular pacing.
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 hemodynamic and electrophysiological action of the HEART VENTRICLES.
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).
Central Venous Pressure
The blood pressure in the central large VEINS of the body. It is distinguished from peripheral venous pressure which occurs in an extremity.
The transference of a heart from one human or animal to another.
A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.
Echocardiography, Doppler, Pulsed
Heart Defects, Congenital
Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.
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)
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
Fundamental claims of patients, as expressed in statutes, declarations, or generally accepted moral principles. (Bioethics Thesaurus) The term is used for discussions of patient rights as a group of many rights, as in a hospital's posting of a list of patient rights.
An antianginal and class III antiarrhythmic drug. It increases the duration of ventricular and atrial muscle action by inhibiting POTASSIUM CHANNELS and VOLTAGE-GATED SODIUM CHANNELS. There is a resulting decrease in heart rate and in vascular resistance.
Tomography, X-Ray Computed
The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.
An electrical current applied to the HEART to terminate a disturbance of its rhythm, ARRHYTHMIAS, CARDIAC. (Stedman, 25th ed)
Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.
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 innermost layer of the heart, comprised of endothelial cells.
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)
One of the three polypeptide chains that make up the TROPONIN complex. It is a cardiac-specific protein that binds to TROPOMYOSIN. It is released from damaged or injured heart muscle cells (MYOCYTES, CARDIAC). Defects in the gene encoding troponin T result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.
Electrophysiologic Techniques, Cardiac
Methods to induce and measure electrical activities at specific sites in the heart to diagnose and treat problems with the heart's electrical system.
Heart Conduction System
An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.
A device designed to stimulate, by electric impulses, contraction of the heart muscles. It may be temporary (external) or permanent (internal or internal-external).
This structure includes the thin muscular atrial septum between the two HEART ATRIA, and the thick muscular ventricular septum between the two HEART VENTRICLES.
Generally, restoration of blood supply to heart tissue which is ischemic due to decrease in normal blood supply. The decrease may result from any source including atherosclerotic obstruction, narrowing of the artery, or surgical clamping. Reperfusion can be induced to treat ischemia. Methods include chemical dissolution of an occluding thrombus, administration of vasodilator drugs, angioplasty, catheterization, and artery bypass graft surgery. However, it is thought that reperfusion can itself further damage the ischemic tissue, causing MYOCARDIAL REPERFUSION INJURY.
Dose-Response Relationship, Drug
A selective phosphodiesterase inhibitor with vasodilating and positive inotropic activity that does not cause changes in myocardial oxygen consumption. It is used in patients with CONGESTIVE HEART FAILURE.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.
Heart Failure, Systolic
Heart failure caused by abnormal myocardial contraction during SYSTOLE leading to defective cardiac emptying.
Heart Valve Diseases
Pathological conditions involving any of the various HEART VALVES and the associated structures (PAPILLARY MUSCLES and CHORDAE TENDINEAE).
A phosphodiesterase inhibitor that blocks uptake and metabolism of adenosine by erythrocytes and vascular endothelial cells. Dipyridamole also potentiates the antiaggregating action of prostacyclin. (From AMA Drug Evaluations Annual, 1994, p752)
Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.
Mineralocorticoid Receptor Antagonists
Ventricular Premature Complexes
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.
A potassium sparing diuretic that acts by antagonism of aldosterone in the distal renal tubules. It is used mainly in the treatment of refractory edema in patients with congestive heart failure, nephrotic syndrome, or hepatic cirrhosis. Its effects on the endocrine system are utilized in the treatments of hirsutism and acne but they can lead to adverse effects. (From Martindale, The Extra Pharmacopoeia, 30th ed, p827)
The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.
Shock resulting from diminution of cardiac output in heart disease.