MITRAL VALVE PROLAPSE

ETIOLOGY

Excessive/redundant mitral leaflet tissue typically of unknown cause; may also accompany certain connective tissue disorders, e.g., Marfan syndrome, Ehlers-Danlos syndrome.

PATHOLOGY

Redundant mitral valve tissue often with myxedematous degeneration and increased glycosaminoglycans.

CLINICAL MANIFESTATIONS

More common in females, most pts are asymptomatic. Yet MVP is the most common cause of primary MR ultimately requiring surgical treatment in North America. Potential symptoms include vague chest discomforts and supraventricular and ventricular arrhythmias. Most important complication is progressive MR. Rarely, systemic emboli from platelet-fibrin deposits on valve lead to transient ischemic attacks. Sudden death is a very rare outcome of MVP.

PHYSICAL EXAMINATION

Mid or late systolic click(s) followed by high-pitched late systolic murmur at the apex (radiates to axilla with anterior leaflet prolapse, often to base with posterior leaflet prolapse). Click and murmur move earlier and are exaggerated by Valsalva maneuver; they are delayed and softened by squatting and isometric exercise (Chap. 112: Physical Examination of the Heart).

ECHOCARDIOGRAM

Shows posterior displacement of one or both mitral leaflets late in systole. Doppler techniques assess severity of accompanying MR. 3-D echo or magnetic reasonance imaging are sometimes used to precisely determine LV volumes.

Treatment: Mitral Valve Prolapse

Asymptomatic pts should be reassured. Beta blockers may lessen chest discomfort and palpitations. Prophylaxis for infective endocarditis is indicated only if prior history of endocarditis. Valve repair or replacement indicated for pts with severe MR who are symptomatic or show progressive LV systolic dysfunction, recent onset AF, or pulmonary hypertension.

Outline

MITRAL VALVE PROLAPSEis the Harrison's Manual of Medicine Word of the day!