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.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.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.Pulmonary Valve: A valve situated at the entrance to the pulmonary trunk from the right ventricle.Heart Valve Prosthesis Implantation: Surgical insertion of synthetic material to repair injured or diseased heart valves.Tricuspid Valve: The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.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).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.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 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.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.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.Prosthesis Design: The plan and delineation of prostheses in general or a specific prosthesis.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 Defects, Congenital: Developmental abnormalities involving structures of the heart. These defects are present at birth but may be discovered later in life.Heart Diseases: Pathological conditions involving the HEART including its structural and functional abnormalities.Tricuspid Valve Insufficiency: Backflow of blood from the RIGHT VENTRICLE into the RIGHT ATRIUM due to imperfect closure of the TRICUSPID VALVE.Calcinosis: Pathologic deposition of calcium salts in tissues.Thromboembolism: Obstruction of a blood vessel (embolism) by a blood clot (THROMBUS) in the blood stream.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.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Heart Transplantation: The transference of a heart from one human or animal to another.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Prosthesis Failure: Malfunction of implantation shunts, valves, etc., and prosthesis loosening, migration, and breaking.Anticoagulants: Agents that prevent clotting.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.Fetal Heart: The heart of the fetus of any viviparous animal. It refers to the heart in the postembryonic period and is differentiated from the embryonic heart (HEART/embryology) only on the basis of time.Mitral Valve 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.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.Echocardiography, Transesophageal: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.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.Cardiac Surgical Procedures: Surgery performed on the heart.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.Heart Valve Prolapse: Downward displacement of any one of the HEART VALVES from its normal position. This usually results in failed valve closure.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.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)Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Endocardium: The innermost layer of the heart, comprised of endothelial cells.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.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.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.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.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.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.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.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.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.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.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.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.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.Papio ursinus: A species of baboon in the family CERCOPITHECIDAE found in southern Africa. They are dark colored and have a variable social structure.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.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.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.Balloon Valvuloplasty: Widening of a stenosed HEART VALVE by the insertion of a balloon CATHETER into the valve and inflation of the balloon.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.Decanoates: Salts and esters of the 10-carbon monocarboxylic acid-decanoic acid.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.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.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.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.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.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.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.Thrombosis: Formation and development of a thrombus or blood clot in the blood vessel.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).Fenfluramine: A centrally active drug that apparently both blocks serotonin uptake and provokes transport-mediated serotonin release.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)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.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.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).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.Hemorrhage: Bleeding or escape of blood from a vessel.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.Embolism: Blocking of a blood vessel by an embolus which can be a blood clot or other undissolved material in the blood stream.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.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).Myocardial Contraction: Contractile activity of the MYOCARDIUM.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).Heart Function Tests: Examinations used to diagnose and treat heart conditions.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.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.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.Biocompatible Materials: Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.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)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.Biomedical Engineering: Application of principles and practices of engineering science to biomedical research and health care.Ileocecal Valve: The valve, at the junction of the CECUM with the COLON, that guards the opening where the ILEUM enters the LARGE INTESTINE.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.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.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)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.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).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.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.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.Heart Injuries: General or unspecified injuries to the heart.Equipment Design: Methods of creating machines and devices.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.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.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.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.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).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.Organogenesis: Formation of differentiated cells and complicated tissue organization to provide specialized functions.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)Myocytes, Cardiac: Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).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.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.Appetite Depressants: Agents that are used to suppress appetite.Fibroma: A benign tumor of fibrous or fully developed connective tissue.Tissue Culture Techniques: A technique for maintaining or growing TISSUE in vitro, usually by DIFFUSION, perifusion, or PERFUSION. The tissue is cultured directly after removal from the host without being dispersed for cell culture.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.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)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.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).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.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.Postoperative Period: The period following a surgical operation.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)Pulmonary Valve Insufficiency: Backflow of blood from the PULMONARY ARTERY into the RIGHT VENTRICLE due to imperfect closure of the PULMONARY VALVE.Hemorheology: The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.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.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.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.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)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.Sus scrofa: A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.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.Streptococcal Infections: Infections with bacteria of the genus STREPTOCOCCUS.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.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.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.Phentermine: A central nervous system stimulant and sympathomimetic with actions and uses similar to those of DEXTROAMPHETAMINE. It has been used most frequently in the treatment of obesity.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Cardiomyopathy, Dilated: A form of CARDIAC MUSCLE disease that is characterized by ventricular dilation, VENTRICULAR DYSFUNCTION, and HEART FAILURE. Risk factors include SMOKING; ALCOHOL DRINKING; HYPERTENSION; INFECTION; PREGNANCY; and mutations in the LMNA gene encoding LAMIN TYPE A, a NUCLEAR LAMINA protein.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.Subgingival Curettage: Removal of degenerated and necrotic epithelium and underlying connective tissue of a periodontal pocket in an effort to convert a chronic ulcerated wound to an acute surgical wound, thereby insuring wound healing and attachment or epithelial adhesion, and shrinkage of the marginal gingiva. The term is sometimes used in connection with smoothing of a root surface or ROOT PLANING. (Jablonski; Illustrated Dictionary of Dentistry, 1982)Vitamin K: A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.Blood Circulation: The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.SOX9 Transcription Factor: A SOXE transcription factor that plays a critical role in regulating CHONDROGENESIS; OSTEOGENESIS; and male sex determination. Loss of function of the SOX9 transcription factor due to genetic mutations is a cause of CAMPOMELIC DYSPLASIA.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.Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Pergolide: A long-acting dopamine agonist which has been used to treat PARKINSON DISEASE and HYPERPROLACTINEMIA but withdrawn from some markets due to potential for HEART VALVE DISEASES.Batch Cell Culture Techniques: Methods for cultivation of cells, usually on a large-scale, in a closed system for the purpose of producing cells or cellular products to harvest.Heart Failure, Systolic: Heart failure caused by abnormal myocardial contraction during SYSTOLE leading to defective cardiac emptying.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Mediastinum: A membrane in the midline of the THORAX of mammals. It separates the lungs between the STERNUM in front and the VERTEBRAL COLUMN behind. It also surrounds the HEART, TRACHEA, ESOPHAGUS, THYMUS, and LYMPH NODES.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).Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Streptococcus sanguis: A gram-positive organism found in dental plaque, in blood, on heart valves in subacute endocarditis, and infrequently in saliva and throat specimens. L-forms are associated with recurrent aphthous stomatitis.Ventricular Remodeling: The geometric and structural changes that the HEART VENTRICLES undergo, usually following MYOCARDIAL INFARCTION. It comprises expansion of the infarct and dilatation of the healthy ventricle segments. While most prevalent in the left ventricle, it can also occur in the right ventricle.Streptococcus anginosus: A species of gram-positive bacteria in the STREPTOCOCCUS MILLERI GROUP. It is the most frequently seen isolate of that group, has a proclivity for abscess formation, and is most often isolated from the blood, gastrointestinal, and urogenital tract.Heart Rate, Fetal: The heart rate of the FETUS. The normal range at term is between 120 and 160 beats per minute.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.Medical Laboratory Science: The specialty related to the performance of techniques in clinical pathology such as those in hematology, microbiology, and other general clinical laboratory applications.Aorta: The main trunk of the systemic arteries.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)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.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Heart Arrest: Cessation of heart beat or MYOCARDIAL CONTRACTION. If it is treated within a few minutes, heart arrest can be reversed in most cases to normal cardiac rhythm and effective circulation.Chondroitinsulfatases: A group of enzymes that catalyze the hydrolysis of various sulfate bonds of chondroitin sulfate. EC 3.1.6.-.Twist Transcription Factor: A basic helix-loop-helix transcription factor that was originally identified in DROSOPHILA as essential for proper gastrulation and MESODERM formation. It plays an important role in EMBRYONIC DEVELOPMENT and CELL DIFFERENTIATION of MUSCLE CELLS, and is found in a wide variety of organisms.