Mitral Valve Prolapse Diagnosis and Clinical Significance

Classic Auscultatory Features

• The American College of Cardiology recommends that a non-ejection click and soft late systolic murmur at the apex is likely caused by mitral valve prolapse, specifically involving a prolapsing mitral leaflet 1, 2
• The midsystolic click results from sudden tensing of the mitral valve apparatus as the leaflets prolapse into the left atrium during systole, and is a key feature of mitral valve prolapse 1, 2, 3
• The late systolic murmur is typically medium-to-high-pitched, loudest at the cardiac apex, and may be soft or have a musical/honking quality, and is a key feature of mitral valve prolapse 1, 2, 4

Dynamic Auscultation

• The American Heart Association notes that standing or Valsalva maneuvers (decreased LV volume) cause the click and murmur to occur earlier in systole, moving closer to S1, which is characteristic of mitral valve prolapse 1, 2, 4
• The American College of Cardiology recommends that squatting (increased LV volume) causes the click-murmur complex to move later toward S2, which is characteristic of mitral valve prolapse 1, 2, 4

Clinical Significance

• The presence of a late systolic murmur indicates some degree of mitral regurgitation, and echocardiography is indicated for diagnosis and assessment of leaflet morphology, degree of regurgitation, and ventricular compensation in patients with physical signs of MVP, according to ACC/AHA guidelines 1, 2, 3