Heart Valves: Flaps of tissue that prevent regurgitation of BLOOD from the HEART VENTRICLES to the HEART ATRIA or from the PULMONARY ARTERIES or AORTA to the ventricles.Heart Valve Prosthesis: A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.Heart Valve Diseases: Pathological conditions involving any of the various HEART VALVES and the associated structures (PAPILLARY MUSCLES and CHORDAE TENDINEAE).Aortic Valve: The valve between the left ventricle and the ascending aorta which prevents backflow into the left ventricle.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.Mitral Valve: The valve between the left atrium and left ventricle of the heart.Heart: The hollow, muscular organ that maintains the circulation of the blood.Bioprosthesis: Prosthesis, usually heart valve, composed of biological material and whose durability depends upon the stability of the material after pretreatment, rather than regeneration by host cell ingrowth. Durability is achieved 1, mechanically by the interposition of a cloth, usually polytetrafluoroethylene, between the host and the graft, and 2, chemically by stabilization of the tissue by intermolecular linking, usually with glutaraldehyde, after removal of antigenic components, or the use of reconstituted and restructured biopolymers.Heart Valve Prosthesis Implantation: Surgical insertion of synthetic material to repair injured or diseased heart valves.Carotid Stenosis: Narrowing or stricture of any part of the CAROTID ARTERIES, most often due to atherosclerotic plaque formation. Ulcerations may form in atherosclerotic plaques and induce THROMBUS formation. Platelet or cholesterol emboli may arise from stenotic carotid lesions and induce a TRANSIENT ISCHEMIC ATTACK; CEREBROVASCULAR ACCIDENT; or temporary blindness (AMAUROSIS FUGAX). (From Adams et al., Principles of Neurology, 6th ed, pp 822-3)Pulmonary Valve: A valve situated at the entrance to the pulmonary trunk from the right ventricle.Mitral Valve Stenosis: Narrowing of the passage through the MITRAL VALVE due to FIBROSIS, and CALCINOSIS in the leaflets and chordal areas. This elevates the left atrial pressure which, in turn, raises pulmonary venous and capillary pressure leading to bouts of DYSPNEA and TACHYCARDIA during physical exertion. RHEUMATIC FEVER is its primary cause.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).Tricuspid Valve: The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.Coronary Stenosis: Narrowing or constriction of a coronary artery.Spinal Stenosis: Narrowing of the spinal canal.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.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.Pulmonary Valve Stenosis: The pathologic narrowing of the orifice of the PULMONARY VALVE. This lesion restricts blood outflow from the RIGHT VENTRICLE to the PULMONARY ARTERY. When the trileaflet valve is fused into an imperforate membrane, the blockage is complete.Tracheal StenosisPyloric Stenosis: Narrowing of the pyloric canal with varied etiology. A common form is due to muscle hypertrophy (PYLORIC STENOSIS, HYPERTROPHIC) seen in infants.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Endocarditis, Bacterial: Inflammation of the ENDOCARDIUM caused by BACTERIA that entered the bloodstream. The strains of bacteria vary with predisposing factors, such as CONGENITAL HEART DEFECTS; HEART VALVE DISEASES; HEART VALVE PROSTHESIS IMPLANTATION; or intravenous drug use.Mitral Valve Prolapse: Abnormal protrusion or billowing of one or both of the leaflets of MITRAL VALVE into the LEFT ATRIUM during SYSTOLE. This allows the backflow of blood into left atrium leading to MITRAL VALVE INSUFFICIENCY; SYSTOLIC MURMURS; or CARDIAC ARRHYTHMIA.Endocarditis: Inflammation of the inner lining of the heart (ENDOCARDIUM), the continuous membrane lining the four chambers and HEART VALVES. It is often caused by microorganisms including bacteria, viruses, fungi, and rickettsiae. Left untreated, endocarditis can damage heart valves and become life-threatening.Prosthesis Design: The plan and delineation of prostheses in general or a specific prosthesis.Calcinosis: Pathologic deposition of calcium salts in tissues.Heart Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.Venous Valves: Flaps within the VEINS that allow the blood to flow only in one direction. They are usually in the medium size veins that carry blood to the heart against gravity.Heart Failure: A heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (VENTRICULAR DYSFUNCTION), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as MYOCARDIAL INFARCTION.Heart Diseases: Pathological conditions involving the HEART including its structural and functional abnormalities.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Tricuspid Valve Insufficiency: Backflow of blood from the RIGHT VENTRICLE into the RIGHT ATRIUM due to imperfect closure of the TRICUSPID VALVE.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Thromboembolism: Obstruction of a blood vessel (embolism) by a blood clot (THROMBUS) in the blood stream.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Tissue Engineering: Generating tissue in vitro for clinical applications, such as replacing wounded tissues or impaired organs. The use of TISSUE SCAFFOLDING enables the generation of complex multi-layered tissues and tissue structures.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Models, Cardiovascular: Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Heart Transplantation: The transference of a heart from one human or animal to another.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Prosthesis Failure: Malfunction of implantation shunts, valves, etc., and prosthesis loosening, migration, and breaking.Anticoagulants: Agents that prevent clotting.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Rheumatic Heart Disease: Cardiac manifestation of systemic rheumatological conditions, such as RHEUMATIC FEVER. Rheumatic heart disease can involve any part the heart, most often the HEART VALVES and the ENDOCARDIUM.Aortic Stenosis, Subvalvular: A pathological constriction occurring in the region below the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Echocardiography, Transesophageal: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Renal Artery Obstruction: Narrowing or occlusion of the RENAL ARTERY or arteries. It is due usually to ATHEROSCLEROSIS; FIBROMUSCULAR DYSPLASIA; THROMBOSIS; EMBOLISM, or external pressure. The reduced renal perfusion can lead to renovascular hypertension (HYPERTENSION, RENOVASCULAR).Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Cardiac Surgical Procedures: Surgery performed on the heart.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Echocardiography, Doppler: Measurement of intracardiac blood flow using an M-mode and/or two-dimensional (2-D) echocardiogram while simultaneously recording the spectrum of the audible Doppler signal (e.g., velocity, direction, amplitude, intensity, timing) reflected from the moving column of red blood cells.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Mitral Valve Annuloplasty: A type of heart valve surgery that involves the repair, replacement, or reconstruction of the annulus of the MITRAL VALVE. It includes shortening the circumference of the annulus to improve valve closing capacity and reinforcing the annulus as a step in more complex valve repairs.Fetal Heart: The heart of the fetus of any viviparous animal. It refers to the heart in the postembryonic period and is differentiated from the embryonic heart (HEART/embryology) only on the basis of time.Aortic Stenosis, Supravalvular: A pathological constriction occurring in the region above the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Reoperation: A repeat operation for the same condition in the same patient due to disease progression or recurrence, or as followup to failed previous surgery.Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Coronary Disease: An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.Absorbable Implants: Implants constructed of materials designed to be absorbed by the body without producing an immune response. They are usually composed of plastics and are frequently used in orthopedics and orthodontics.Coronary Angiography: Radiography of the vascular system of the heart muscle after injection of a contrast medium.International Normalized Ratio: System established by the World Health Organization and the International Committee on Thrombosis and Hemostasis for monitoring and reporting blood coagulation tests. Under this system, results are standardized using the International Sensitivity Index for the particular test reagent/instrument combination used.Endocardial Cushions: A fetal heart structure that is the bulging areas in the cardiac septum between the HEART ATRIA and the HEART VENTRICLES. During development, growth and fusion of endocardial cushions at midline forms the two atrioventricular canals, the sites for future TRICUSPID VALVE and BICUSPID VALVE.Endocardium: The innermost layer of the heart, comprised of endothelial cells.Heart Sounds: The sounds heard over the cardiac region produced by the functioning of the heart. There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is heard as a "lubb" sound; the second is produced by the closing of the AORTIC VALVE and PULMONARY VALVE and is heard as a "dupp" sound; the third is produced by vibrations of the ventricular walls when suddenly distended by the rush of blood from the HEART ATRIA; and the fourth is produced by atrial contraction and ventricular filling.Echocardiography, Doppler, Color: Echocardiography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image.Heart Valve Prolapse: Downward displacement of any one of the HEART VALVES from its normal position. This usually results in failed valve closure.Cardiac Valve Annuloplasty: A type of heart valve surgery that involves the repair, replacement, or reconstruction of the annuli of HEART VALVES. It includes shortening the circumference of the annulus to improve valve closing capacity and reinforcing the annulus as a step in more complex valve repairs.Warfarin: An anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide.Acenocoumarol: A coumarin that is used as an anticoagulant. Its actions and uses are similar to those of WARFARIN. (From Martindale, The Extra Pharmacopoeia, 30th ed, p233)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.Multidetector Computed Tomography: Types of spiral computed tomography technology in which multiple slices of data are acquired simultaneously improving the resolution over single slice acquisition technology.Ultrasonography, Doppler, Duplex: Ultrasonography applying the Doppler effect combined with real-time imaging. The real-time image is created by rapid movement of the ultrasound beam. A powerful advantage of this technique is the ability to estimate the velocity of flow from the Doppler shift frequency.Carotid Artery, Internal: Branch of the common carotid artery which supplies the anterior part of the brain, the eye and its appendages, the forehead and nose.Angioplasty, Balloon: Use of a balloon catheter for dilation of an occluded artery. It is used in treatment of arterial occlusive diseases, including renal artery stenosis and arterial occlusions in the leg. For the specific technique of BALLOON DILATION in coronary arteries, ANGIOPLASTY, BALLOON, CORONARY is available.Pregnancy Complications, Cardiovascular: The co-occurrence of pregnancy and a cardiovascular disease. The disease may precede or follow FERTILIZATION and it may or may not have a deleterious effect on the pregnant woman or FETUS.Endarterectomy, Carotid: The excision of the thickened, atheromatous tunica intima of a carotid artery.Phonocardiography: Graphic registration of the heart sounds picked up as vibrations and transformed by a piezoelectric crystal microphone into a varying electrical output according to the stresses imposed by the sound waves. The electrical output is amplified by a stethograph amplifier and recorded by a device incorporated into the electrocardiograph or by a multichannel recording machine.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Laryngostenosis: Developmental or acquired stricture or narrowing of the LARYNX. Symptoms of respiratory difficulty depend on the degree of laryngeal narrowing.Amaurosis Fugax: Transient complete or partial monocular blindness due to retinal ischemia. This may be caused by emboli from the CAROTID ARTERY (usually in association with CAROTID STENOSIS) and other locations that enter the central RETINAL ARTERY. (From Adams et al., Principles of Neurology, 6th ed, p245)Discrete Subaortic Stenosis: A type of constriction that is caused by the presence of a fibrous ring (discrete type) below the AORTIC VALVE, anywhere between the aortic valve and the MITRAL VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.Tricuspid Valve Stenosis: The pathologic narrowing of the orifice of the TRICUSPID VALVE. This hinders the emptying of RIGHT ATRIUM leading to elevated right atrial pressure and systemic venous congestion. Tricuspid valve stenosis is almost always due to RHEUMATIC FEVER.Thrombosis: Formation and development of a thrombus or blood clot in the blood vessel.Angiography: Radiography of blood vessels after injection of a contrast medium.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Glutaral: One of the protein CROSS-LINKING REAGENTS that is used as a disinfectant for sterilization of heat-sensitive equipment and as a laboratory reagent, especially as a fixative.Embolism: Blocking of a blood vessel by an embolus which can be a blood clot or other undissolved material in the blood stream.Magnetic Resonance Angiography: Non-invasive method of vascular imaging and determination of internal anatomy without injection of contrast media or radiation exposure. The technique is used especially in CEREBRAL ANGIOGRAPHY as well as for studies of other vascular structures.Bioreactors: Tools or devices for generating products using the synthetic or chemical conversion capacity of a biological system. They can be classical fermentors, cell culture perfusion systems, or enzyme bioreactors. For production of proteins or enzymes, recombinant microorganisms such as bacteria, mammalian cells, or insect or plant cells are usually chosen.Ultrasonography, Doppler, Transcranial: A non-invasive technique using ultrasound for the measurement of cerebrovascular hemodynamics, particularly cerebral blood flow velocity and cerebral collateral flow. With a high-intensity, low-frequency pulse probe, the intracranial arteries may be studied transtemporally, transorbitally, or from below the foramen magnum.Carcinoid Heart Disease: Cardiac manifestation of gastrointestinal CARCINOID TUMOR that metastasizes to the liver. Substances secreted by the tumor cells, including SEROTONIN, promote fibrous plaque formation in ENDOCARDIUM and its underlying layers. These deposits cause distortion of the TRICUSPID VALVE and the PULMONARY VALVE eventually leading to STENOSIS and valve regurgitation.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Arterial Occlusive Diseases: Pathological processes which result in the partial or complete obstruction of ARTERIES. They are characterized by greatly reduced or absence of blood flow through these vessels. They are also known as arterial insufficiency.Ventricular Function, Left: The hemodynamic and electrophysiological action of the left HEART VENTRICLE. Its measurement is an important aspect of the clinical evaluation of patients with heart disease to determine the effects of the disease on cardiac performance.Heart Block: Impaired conduction of cardiac impulse that can occur anywhere along the conduction pathway, such as between the SINOATRIAL NODE and the right atrium (SA block) or between atria and ventricles (AV block). Heart blocks can be classified by the duration, frequency, or completeness of conduction block. Reversibility depends on the degree of structural or functional defects.Papio ursinus: A species of baboon in the family CERCOPITHECIDAE found in southern Africa. They are dark colored and have a variable social structure.Pericardium: A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.Embolism, Air: Blocking of a blood vessel by air bubbles that enter the circulatory system, usually after TRAUMA; surgical procedures, or changes in atmospheric pressure.Chordae Tendineae: The tendinous cords that connect each cusp of the two atrioventricular HEART VALVES to appropriate PAPILLARY MUSCLES in the HEART VENTRICLES, preventing the valves from reversing themselves when the ventricles contract.Myocardial Ischemia: A disorder of cardiac function caused by insufficient blood flow to the muscle tissue of the heart. The decreased blood flow may be due to narrowing of the coronary arteries (CORONARY ARTERY DISEASE), to obstruction by a thrombus (CORONARY THROMBOSIS), or less commonly, to diffuse narrowing of arterioles and other small vessels within the heart. Severe interruption of the blood supply to the myocardial tissue may result in necrosis of cardiac muscle (MYOCARDIAL INFARCTION).Balloon Valvuloplasty: Widening of a stenosed HEART VALVE by the insertion of a balloon CATHETER into the valve and inflation of the balloon.Pyloric Stenosis, Hypertrophic: Narrowing of the pyloric canal due to HYPERTROPHY of the surrounding circular muscle. It is usually seen in infants or young children.Decanoates: Salts and esters of the 10-carbon monocarboxylic acid-decanoic acid.Myocardial Contraction: Contractile activity of the MYOCARDIUM.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Hemorrhage: Bleeding or escape of blood from a vessel.Stroke Volume: The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.Receptor, Serotonin, 5-HT2B: A serotonin receptor subtype found in the BRAIN; HEART; LUNGS; PLACENTA and DIGESTIVE SYSTEM organs. A number of functions have been attributed to the action of the 5-HT2B receptor including the development of cardiac myocytes (MYOCYTES, CARDIAC) and the contraction of SMOOTH MUSCLE.Heart Arrest, Induced: A procedure to stop the contraction of MYOCARDIUM during HEART SURGERY. It is usually achieved with the use of chemicals (CARDIOPLEGIC SOLUTIONS) or cold temperature (such as chilled perfusate).Safety-Based Drug Withdrawals: Removal of a drug from the market due to the identification of an intrinsic property of the drug that results in a serious risk to public health.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Heart Neoplasms: Tumors in any part of the heart. They include primary cardiac tumors and metastatic tumors to the heart. Their interference with normal cardiac functions can cause a wide variety of symptoms including HEART FAILURE; CARDIAC ARRHYTHMIAS; or EMBOLISM.Angiography, Digital Subtraction: A method of delineating blood vessels by subtracting a tissue background image from an image of tissue plus intravascular contrast material that attenuates the X-ray photons. The background image is determined from a digitized image taken a few moments before injection of the contrast material. The resulting angiogram is a high-contrast image of the vessel. This subtraction technique allows extraction of a high-intensity signal from the superimposed background information. The image is thus the result of the differential absorption of X-rays by different tissues.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.Cardiomyopathies: A group of diseases in which the dominant feature is the involvement of the CARDIAC MUSCLE itself. Cardiomyopathies are classified according to their predominant pathophysiological features (DILATED CARDIOMYOPATHY; HYPERTROPHIC CARDIOMYOPATHY; RESTRICTIVE CARDIOMYOPATHY) or their etiological/pathological factors (CARDIOMYOPATHY, ALCOHOLIC; ENDOCARDIAL FIBROELASTOSIS).Esophageal Stenosis: A stricture of the ESOPHAGUS. Most are acquired but can be congenital.Intracranial Embolism and Thrombosis: Embolism or thrombosis involving blood vessels which supply intracranial structures. Emboli may originate from extracranial or intracranial sources. Thrombosis may occur in arterial or venous structures.Equipment Design: Methods of creating machines and devices.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Recurrence: The return of a sign, symptom, or disease after a remission.Graft Occlusion, Vascular: Obstruction of flow in biological or prosthetic vascular grafts.Fenfluramine: A centrally active drug that apparently both blocks serotonin uptake and provokes transport-mediated serotonin release.Extracellular Matrix: A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.Heart Function Tests: Examinations used to diagnose and treat heart conditions.Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Tensile Strength: The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)Angioplasty: Reconstruction or repair of a blood vessel, which includes the widening of a pathological narrowing of an artery or vein by the removal of atheromatous plaque material and/or the endothelial lining as well, or by dilatation (BALLOON ANGIOPLASTY) to compress an ATHEROMA. Except for ENDARTERECTOMY, usually these procedures are performed via catheterization as minimally invasive ENDOVASCULAR PROCEDURES.Sheep: Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.Bioartificial Organs: Artificial organs that are composites of biomaterials and cells. The biomaterial can act as a membrane (container) as in BIOARTIFICIAL LIVER or a scaffold as in bioartificial skin.Intracranial Arteriosclerosis: Vascular diseases characterized by thickening and hardening of the walls of ARTERIES inside the SKULL. There are three subtypes: (1) atherosclerosis with fatty deposits in the ARTERIAL INTIMA; (2) Monckeberg's sclerosis with calcium deposits in the media and (3) arteriolosclerosis involving the small caliber arteries. Clinical signs include HEADACHE; CONFUSION; transient blindness (AMAUROSIS FUGAX); speech impairment; and HEMIPARESIS.Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Tissue Preservation: The process by which a tissue or aggregate of cells is kept alive outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Postoperative Period: The period following a surgical operation.Heart Septal Defects, Ventricular: Developmental abnormalities in any portion of the VENTRICULAR SEPTUM resulting in abnormal communications between the two lower chambers of the heart. Classification of ventricular septal defects is based on location of the communication, such as perimembranous, inlet, outlet (infundibular), central muscular, marginal muscular, or apical muscular defect.Equipment Failure Analysis: 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.Biocompatible Materials: Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.Coronary Vessels: The veins and arteries of the HEART.Ventricular Dysfunction, Left: A condition in which the LEFT VENTRICLE of the heart was functionally impaired. This condition usually leads to HEART FAILURE; MYOCARDIAL INFARCTION; and other cardiovascular complications. Diagnosis is made by measuring the diminished ejection fraction and a depressed level of motility of the left ventricular wall.Biomedical Engineering: Application of principles and practices of engineering science to biomedical research and health care.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Hemorheology: The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.Tissue Scaffolds: Cell growth support structures composed of BIOCOMPATIBLE MATERIALS. They are specially designed solid support matrices for cell attachment in TISSUE ENGINEERING and GUIDED TISSUE REGENERATION uses.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Prothrombin Time: Clotting time of PLASMA recalcified in the presence of excess TISSUE THROMBOPLASTIN. Factors measured are FIBRINOGEN; PROTHROMBIN; FACTOR V; FACTOR VII; and FACTOR X. It is used for monitoring anticoagulant therapy with COUMARINS.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Ileocecal Valve: The valve, at the junction of the CECUM with the COLON, that guards the opening where the ILEUM enters the LARGE INTESTINE.Fractional Flow Reserve, Myocardial: The ratio of maximum blood flow to the MYOCARDIUM with CORONARY STENOSIS present, to the maximum equivalent blood flow without stenosis. The measurement is commonly used to verify borderline stenosis of CORONARY ARTERIES.Pulmonary Valve Insufficiency: Backflow of blood from the PULMONARY ARTERY into the RIGHT VENTRICLE due to imperfect closure of the PULMONARY VALVE.Echocardiography, Three-Dimensional: Echocardiography amplified by the addition of depth to the conventional two-dimensional ECHOCARDIOGRAPHY visualizing only the length and width of the heart. Three-dimensional ultrasound imaging was first described in 1961 but its application to echocardiography did not take place until 1974. (Mayo Clin Proc 1993;68:221-40)Carotid Artery Diseases: Pathological conditions involving the CAROTID ARTERIES, including the common, internal, and external carotid arteries. ATHEROSCLEROSIS and TRAUMA are relatively frequent causes of carotid artery pathology.Carotid Arteries: Either of the two principal arteries on both sides of the neck that supply blood to the head and neck; each divides into two branches, the internal carotid artery and the external carotid artery.Systole: Period of contraction of the HEART, especially of the HEART VENTRICLES.Intracranial Embolism: Blocking of a blood vessel in the SKULL by an EMBOLUS which can be a blood clot (THROMBUS) or other undissolved material in the blood stream. Most emboli are of cardiac origin and are associated with HEART DISEASES. Other non-cardiac sources of emboli are usually associated with VASCULAR DISEASES.Vertebrobasilar Insufficiency: Localized or diffuse reduction in blood flow through the vertebrobasilar arterial system, which supplies the BRAIN STEM; CEREBELLUM; OCCIPITAL LOBE; medial TEMPORAL LOBE; and THALAMUS. Characteristic clinical features include SYNCOPE; lightheadedness; visual disturbances; and VERTIGO. BRAIN STEM INFARCTIONS or other BRAIN INFARCTION may be associated.Vascular Patency: The degree to which BLOOD VESSELS are not blocked or obstructed.Stroke: A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)Exercise Test: Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.Age Factors: 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.Sternum: A long, narrow, and flat bone commonly known as BREASTBONE occurring in the midsection of the anterior thoracic segment or chest region, which stabilizes the rib cage and serves as the point of origin for several muscles that move the arms, head, and neck.Cerebral Angiography: Radiography of the vascular system of the brain after injection of a contrast medium.Heart Septal Defects: Abnormalities in any part of the HEART SEPTUM resulting in abnormal communication between the left and the right chambers of the heart. The abnormal blood flow inside the heart may be caused by defects in the ATRIAL SEPTUM, the VENTRICULAR SEPTUM, or both.Heart Injuries: General or unspecified injuries to the heart.Atrial Fibrillation: 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.Endocarditis, Subacute Bacterial: ENDOCARDIUM infection that is usually caused by STREPTOCOCCUS. Subacute infective endocarditis evolves over weeks and months with modest toxicity and rare metastatic infection.Ultrasonography, Doppler, Color: Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region.Observer Variation: The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).Cardiac-Gated Imaging Techniques: Timing the acquisition of imaging data to specific points in the cardiac cycle to minimize image blurring and other motion artifacts.Ischemic Attack, Transient: Brief reversible episodes of focal, nonconvulsive ischemic dysfunction of the brain having a duration of less than 24 hours, and usually less than one hour, caused by transient thrombotic or embolic blood vessel occlusion or stenosis. Events may be classified by arterial distribution, temporal pattern, or etiology (e.g., embolic vs. thrombotic). (From Adams et al., Principles of Neurology, 6th ed, pp814-6)Prosthesis-Related Infections: Infections resulting from the implantation of prosthetic devices. The infections may be acquired from intraoperative contamination (early) or hematogenously acquired from other sites (late).Rheology: The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.Phenindione: An indandione that has been used as an anticoagulant. Phenindione has actions similar to WARFARIN, but it is now rarely employed because of its higher incidence of severe adverse effects. (From Martindale, The Extra Pharmacopoeia, 30th ed, p234)Cardiomegaly: Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.Sus scrofa: A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.Cohort Studies: 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.Myocytes, Cardiac: Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Aortic Valve Prolapse: The downward displacement of the cuspal or pointed end of the trileaflet AORTIC VALVE causing misalignment of the cusps. Severe valve distortion can cause leakage and allow the backflow of blood from the ASCENDING AORTA back into the LEFT VENTRICLE, leading to aortic regurgitation.Hypertension, Renovascular: Hypertension due to RENAL ARTERY OBSTRUCTION or compression.Arteriovenous Shunt, Surgical: Surgical shunt allowing direct passage of blood from an artery to a vein. (From Dorland, 28th ed)Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Cerebrovascular Disorders: A spectrum of pathological conditions of impaired blood flow in the brain. They can involve vessels (ARTERIES or VEINS) in the CEREBRUM, the CEREBELLUM, and the BRAIN STEM. Major categories include INTRACRANIAL ARTERIOVENOUS MALFORMATIONS; BRAIN ISCHEMIA; CEREBRAL HEMORRHAGE; and others.Organogenesis: Formation of differentiated cells and complicated tissue organization to provide specialized functions.Pulmonary Subvalvular Stenosis: Narrowing below the PULMONARY VALVE or well below it in the infundibuluar chamber where the pulmonary artery originates, usually caused by a defective VENTRICULAR SEPTUM or presence of fibrous tissues. It is characterized by restricted blood outflow from the RIGHT VENTRICLE into the PULMONARY ARTERY, exertional fatigue, DYSPNEA, and chest discomfort.Cardiotonic Agents: Agents that have a strengthening effect on the heart or that can increase cardiac output. They may be CARDIAC GLYCOSIDES; SYMPATHOMIMETICS; or other drugs. They are used after MYOCARDIAL INFARCT; CARDIAC SURGICAL PROCEDURES; in SHOCK; or in congestive heart failure (HEART FAILURE).Chi-Square Distribution: 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.Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Heart, Artificial: A pumping mechanism that duplicates the output, rate, and blood pressure of the natural heart. It may replace the function of the entire heart or a portion of it, and may be an intracorporeal, extracorporeal, or paracorporeal heart. (Dorland, 28th ed)Pulsatile Flow: Rhythmic, intermittent propagation of a fluid through a BLOOD VESSEL or piping system, in contrast to constant, smooth propagation, which produces laminar flow.Aorta: The main trunk of the systemic arteries.Diastole: Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Electrocardiography: Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.
  • Normally the right side of the heart pumps blood to the lungs. (heart.org)
  • Pulmonary stenosis is a narrowing of the valve that lets blood flow from the lower-right chamber (the right ventricle) into the lungs. (texasheart.org)
  • This can cause blood to back up elsewhere in the heart, and even back into the lungs . (webmd.com)
  • In mitral valve stenosis, pressure that builds up in the heart is then sent back to the lungs, resulting in fluid buildup (congestion) and shortness of breath. (mayoclinic.org)
  • Abnormality in the mitral valve, for example, affects blood flow to the lungs because it located on the left side of the heart, while the tricuspid valve, found on the right side of the heart, affects blood flow to the rest of the body. (petmd.com)
  • Pulmonary capillary pressures in this level cause an imbalance between the hydrostatic pressure and the oncotic pressure, leading to extravasation of fluid from the vascular tree and pooling of fluid in the lungs (congestive heart failure causing pulmonary edema). (wikipedia.org)
  • Chest X-rays use a small dose of radiation to create pictures of the structures inside the chest, including the lungs, heart and chest wall. (medstarheartinstitute.org)
  • This pattern is repeated over and over, causing blood to flow continuously to the heart, lungs and body. (medicinenet.com)
  • The pulmonary (or pulmonic) valve lies between the right ventricle (lower heart chamber) and the pulmonary artery, which sends blood to the lungs to pick up oxygen to deliver to the body. (henryford.com)
  • The narrowed opening prevents blood from flowing forward through the heart to the lungs. (henryford.com)
  • Although some blood flows forward into the lungs, the blood that leaks backward can build up in the heart. (henryford.com)
  • Two other valves control blood flow from the ventricles, one to the lungs and the other to the rest of the body. (blausen.com)
  • This procedure allows for the heart to pump more effectively, reducing pressure in the heart and lungs. (blausen.com)
  • Once back in the heart, the blood flows along to the lungs, where it disposes of carbon dioxide and restocks its supply of oxygen before cycling through your body once more. (healthcentral.com)
  • In this approach, the surgery is performed through a small incision, providing access to the heart and lungs for surgical procedures such as aortic valve replacements, and mitral valve repairs and replacements. (ucsd.edu)
  • Cardiopulmonary bypass serves as a temporary substitute for a patient's heart and lungs during the course of open-heart surgery . (britannica.com)
  • With this machine the blood bypasses the heart and lungs so that the surgeon has an unobstructed view of the operative field. (britannica.com)
  • In this manner, oxygen is introduced into the blood, and carbon dioxide is removed in sufficient quantities to make the blood leaving the oxygenator similar to that normally returning to the heart from the lungs. (britannica.com)
  • The resilient member is disposed about the support member and has a resiliency substantially equal to the resiliency of a sewing ring of the artificial heart valve. (google.com)
  • said resilient member having a resiliency substantially the same as the resiliency of the sewing ring of the artificial heart valve. (google.com)
  • 5. A sizer as claimed in claim 1 wherein said resilient member is configured substantially the same as the sewing ring of the artificial heart valve. (google.com)
  • However, children grow, and the artificial heart valve may not be able to accommodate the heart's increasing size. (news-medical.net)