Mitral valve prolapse.

Mitral valve prolapse (MVP) now is a commonly recognized syndrome with an apparent prevalence of approximately 4-6%. It appears to occur more frequently in females and occasionally it is familial. In most instances, the syndrome is idiopathic, although it occurs in association with many other conditions, particularly Marfan's syndrome, rheumatic heart disease, coronary heart disease, congestive cardiomyopathy, ostium secundum atrial septal defect, Ehlers-Danlos syndrome or abnormalities of the thoracic cage. The majority of patients with the syndrome have minimal, if any, symptoms and have a benign course. When symptoms do occur, more frequently they are palpitations, chest pain, dyspnea on exertion or fatigue. Neuropsychiatric symptoms or even transient ischemic episodes may occur rarely. Very rarely, complications such as severe mitral regurgitation, arrhythmias or infective endocarditis may occur. Characteristically, patients have a midsystolic click, occasionally followed by a systolic murmur. The timing of the click and the onset of the murmur usually is variable, depending on the ventricular volume. The electrocardiogram frequently shows ST-T wave changes. The diagnosis usually can be confirmed by echocardiography or left ventricular angiography. Most patients with MVP require no treatment other than reassurance. If a systolic murmur is present, prophylaxis against infective endocarditis during dental work probably is useful. Patients with palpitations or chest pain usually respond well to treatment with propranolol. Patients with progressive severe mitral regurgitation require mitral valve replacement.