• (mitral stenosis) An abnormal narrowing of the orifice of the mitral valve.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2025
• A narrowing of the mitral valve opening that limits blood flow from the left atrium to the left ventricle.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• Narrowing of the left atrioventricular mitral orifice.
  NCI
  U.S. National Cancer Institute, 2021
• 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.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Obstruction of flow across a mitral heart valve due to immobility reduced elasticity of the leaflets and/or a restricted orifice.
  U.S. FDA Glossary
  U.S. Food & Drug Administration, 2021
• Rheumatic disease causing diffuse thickening of the mitral valve leaflets by fibrous tissue or calcific deposits.
  CRISP Thesaurus
  National Institutes of Health, 2006
• Mitral stenosis is narrowing of the mitral orifice that impedes blood flow from the left atrium to the left ventricle. The (almost) invariable cause is rheumatic fever. Common complications are pulmonary hypertension, atrial fibrillation, and thromboembolism. Symptoms are those of heart failure; signs include an opening snap and a...
  Merck Manuals
  Merck & Co., Inc., 2025
• Mitral stenosis (MS) is characterized by obstruction to left ventricular inflow at the level of mitral valve due to structural abnormality of the mitral valve apparatus. The most common cause of mitral stenosis is rheumatic fever.
  Medscape
  WebMD, 2025
• Mitral valve stenosis - or mitral stenosis - is a narrowing of the heart's mitral valve. This abnormal valve doesn't open properly, blocking blood flow into the main pumping chamber of your heart (left ventricle). Mitral valve stenosis can make you tired and short of breath, among other problems.
  Mayo Clinic
  Mayo Foundation for Medical Education and Research, 2025
• Mitral stenosis is a narrowing of the mitral valve orifice, usually caused by rheumatic valvulitis producing fusion of the valve commissures and thickening of the valve leaflets.
  Epocrates
  Athenahealth, Inc., 2019
• Mitral stenosis, narrowing of the mitral valve, the function of which is to permit blood to flow from the atrium, or upper chamber, to the ventricle, or lower chamber, of the left side of the heart and to prevent its backflow. Narrowing of the mitral valve is usually a result of rheumatic fever;...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025