Mitral valve prolapse: causes, clinical manifestations, and management.

PURPOSE: To assess the causes, methods of diagnosis, clinical spectrum, and management of mitral valve prolapse.

DATA IDENTIFICATION: Results of prospective study of over 800 subjects at Cornell Medical Center from 1979 to the present were used along with studies published from 1963 to 1989 identified by computerized literature searches of Index Medicus and MEDLINE, and by hand searches.

STUDY SELECTION: Studies involving controlled design, longitudinal follow-up, or critical assessment of diagnostic methodology, and clinical studies or previous reviews that have contributed most to the understanding of mitral valve prolapse were selected.

DATA EXTRACTION: Data concerning the causes, clinical manifestations and complications, and prevalence of mitral valve prolapse, as well as the strength of association between mitral valve prolapse and diagnostic signs, were evaluated and used to develop a practical approach to evaluating and managing patients.

RESULTS OF DATA SYNTHESIS: Most instances of mitral valve prolapse are primary and inherited, with possible genetic heterogeneity. Mitral prolapse may be diagnosed by auscultation of midsystolic clicks and late-systolic murmurs that respond typically to maneuvers, or by billowing of mitral leaflets across the mitral anular plane in long-axis, two-dimensional echocardiographic views or by a late-systolic, posterior leaflet displacement of at least 2 mm in meticulously targeted M-mode recordings. Mitral valve prolapse is associated with thoracic bony abnormalities, low body weight, low blood pressure, and a modest excess of orthostatic hypotension, syncope, palpitations, and atrial arrhythmias, but not with nonspecific symptoms (atypical chest pain, dyspnea, anxiety or panic attacks). Complications of mitral valve prolapse, including about 4000 mitral valve operations, 1100 cases of endocarditis, and possibly 4000 sudden deaths per year in the United States, are concentrated disproportionately in older men, with about 5% of affected men and 1.5% of affected women ultimately requiring valve surgery.

CONCLUSIONS: Prophylaxis for endocarditis and closeness of follow-up should be related to the occurrence of the independent risk factors for complications of mitral prolapse (presence of mitral regurgitation, male gender, and age over 45 years), whereas active management and close observation are needed for severe mitral regurgitation and advanced ventricular arrhythmias.