Heart Valve Diseases: Pathological conditions involving any of the various HEART VALVES and the associated structures (PAPILLARY MUSCLES and CHORDAE TENDINEAE).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.Aortic Valve: The valve between the left ventricle and the ascending aorta which prevents backflow into the left ventricle.Heart Valve Prosthesis: A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.Mitral Valve: The valve between the left atrium and left ventricle of the heart.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.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).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: The hollow, muscular organ that maintains the circulation of the blood.Heart Valve Prosthesis Implantation: Surgical insertion of synthetic material to repair injured or diseased heart valves.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: 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.Tricuspid Valve: The valve consisting of three cusps situated between the right atrium and right ventricle of the heart.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.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.Calcinosis: Pathologic deposition of calcium salts in tissues.Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Tricuspid Valve Insufficiency: Backflow of blood from the RIGHT VENTRICLE into the RIGHT ATRIUM due to imperfect closure of the TRICUSPID VALVE.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.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.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.Echocardiography: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic.Heart Diseases: Pathological conditions involving the HEART including its structural and functional abnormalities.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.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.Prosthesis Design: The plan and delineation of prostheses in general or a specific prosthesis.Cardiac Catheterization: Procedures in which placement of CARDIAC CATHETERS is performed for therapeutic or diagnostic procedures.Echocardiography, Transesophageal: Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues using a transducer placed in the esophagus.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.Cardiac Surgical Procedures: Surgery performed on the heart.Heart Atria: The chambers of the heart, to which the BLOOD returns from the circulation.Digitalis Glycosides: Glycosides from plants of the genus DIGITALIS. Some of these are useful as cardiotonic and anti-arrhythmia agents. Included also are semi-synthetic derivatives of the naturally occurring glycosides. The term has sometimes been used more broadly to include all CARDIAC GLYCOSIDES, but here is restricted to those related to Digitalis.Digitalis: A genus of toxic herbaceous Eurasian plants of the Plantaginaceae which yield cardiotonic DIGITALIS GLYCOSIDES. The most useful species are Digitalis lanata and D. purpurea.Nifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.Digoxin: A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666)Hydralazine: A direct-acting vasodilator that is used as an antihypertensive agent.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)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.Balloon Valvuloplasty: Widening of a stenosed HEART VALVE by the insertion of a balloon CATHETER into the valve and inflation of the balloon.Rheumatic Fever: A febrile disease occurring as a delayed sequela of infections with STREPTOCOCCUS PYOGENES. It is characterized by multiple focal inflammatory lesions of the connective tissue structures, such as the heart, blood vessels, and joints (POLYARTHRITIS) and brain, and by the presence of ASCHOFF BODIES in the myocardium and skin.Norfenfluramine: A FENFLURAMINE analog that inhibits serotonin uptake and may provoke release of serotonin. It is used as an appetite depressant and an experimental tool in animal studies.Galega: A plant genus of the family FABACEAE that contains galegine (GUANIDINES). Most of the other species have been reclassified to TEPHROSIA; a few to ASTRAGALUS PLANT; and INDIGOFERA.History, 20th Century: Time period from 1901 through 2000 of the common era.Mucopolysaccharidosis II: Systemic lysosomal storage disease marked by progressive physical deterioration and caused by a deficiency of L-sulfoiduronate sulfatase. This disease differs from MUCOPOLYSACCHARIDOSIS I by slower progression, lack of corneal clouding, and X-linked rather than autosomal recessive inheritance. The mild form produces near-normal intelligence and life span. The severe form usually causes death by age 15.Cardiac Care Facilities: Institutions specializing in the care of patients with heart disorders.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Myocardial Infarction: NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).Heart Murmurs: Heart sounds caused by vibrations resulting from the flow of blood through the heart. Heart murmurs can be examined by HEART AUSCULTATION, and analyzed by their intensity (6 grades), duration, timing (systolic, diastolic, or continuous), location, transmission, and quality (musical, vibratory, blowing, etc).Anniversaries and Special Events: Occasions to commemorate an event or occasions designated for a specific purpose.Awareness: The act of "taking account" of an object or state of affairs. It does not imply assessment of, nor attention to the qualities or nature of the object.