Physical Cardiac Exam Findings in Anterior Mitral Valve Prolapse with Regurgitation

Primary Auscultatory Findings

A nonejection midsystolic click represents the sudden tensing of the mitral valve apparatus as the anterior leaflet prolapses into the left atrium during systole, best heard at the apex with possible radiation to the axilla 1
The click may occur as a single sound or as multiple clicks, and its timing moves within systole with changes in left ventricular dimensions 1
In mild-to-moderate anterior MVP with regurgitation, expect a late systolic murmur that begins after the midsystolic click and extends to S2, best heard at the apex and may radiate to the axilla 1
In severe MVP with regurgitation, a loud holosystolic murmur may be heard at the apex, though this is less common 1

A very late soft systolic murmur without diastolic filling sounds indicates that regurgitation occurs only in very late systole 1

Normal intensity and splitting of S2 is typically preserved in mild MVP 1
An early diastolic filling sound (S3) may be present in severe mitral regurgitation with significant volume overload 1
Normal left ventricular and left atrial examination findings suggest that severe chronic mitral regurgitation is unlikely, even if echocardiography suggests otherwise 1
Signs of pulmonary congestion may be present in severe regurgitation with hemodynamic compromise 1

Standing from squatting or Valsalva maneuver decreases left ventricular volume, causing the click to occur earlier in systole and the murmur to become longer and louder 1
Squatting or leg raising increases left ventricular volume, causing the click to occur later in systole and the murmur to become shorter and softer 1

Failing to examine in multiple positions may miss MVP, as the physical examination in these positions is optimal for detection 1
Misinterpreting grade 1-2 systolic ejection murmurs at the left sternal border as MVP when they actually represent innocent flow murmurs 1
In secondary MR with left ventricular dysfunction, the anterior leaflet may appear to override the posterior leaflet at end-systole, mimicking prolapse, but in true anterior MVP, the leaflet moves superiorly beyond the mitral annular plane into the left atrium 2
When physical examination shows only a very late soft systolic murmur with normal chamber findings, but echocardiography suggests severe MR, the echocardiogram likely overestimates severity by not accounting for the short duration of late systolic regurgitation 1