What are the expected physical cardiac examination findings in a patient with mitral (mitral valve) prolapse and regurgitation?

Expected Physical Cardiac Examination Findings in Mitral Valve Prolapse with Regurgitation

The classic physical examination findings in mitral valve prolapse (MVP) with regurgitation consist of a midsystolic click followed by a late systolic murmur heard at the apex, though the timing and characteristics of these findings vary significantly based on the severity and timing of regurgitation. 1

Primary Auscultatory Findings

Midsystolic Click

• A nonejection midsystolic click is the hallmark finding and represents the sudden tensing of the mitral valve apparatus as the leaflets prolapse into the left atrium during systole 1, 2
• The click may occur as a single sound or as multiple clicks 1
• The timing of the click moves within systole with changes in left ventricular dimensions 1

Systolic Murmur Characteristics

• In mild-to-moderate MVP with regurgitation, expect a late systolic murmur that begins after the midsystolic click and extends to S2 1
• In severe MVP with regurgitation, a loud holosystolic murmur may be heard at the apex, though this is less common 1, 3
• The murmur is best heard at the apex and may radiate to the axilla 3
• A very late, soft systolic murmur with no diastolic filling sound suggests that regurgitation occurs only in very late systole, which is common in MVP 1

Critical Timing Considerations

The timing of the murmur is diagnostically crucial and directly correlates with severity:

• Mid-late systolic MR produces a shorter duration murmur (approximately 233 ms) compared to holosystolic MR (426 ms), despite similar instantaneous severity 4
• Pure late systolic regurgitation indicates less severe hemodynamic consequences than holosystolic regurgitation, even when color Doppler jet area appears similar 4
• The physical examination demonstrating very late soft systolic murmur without diastolic filling sounds indicates that regurgitation occurs only in very late systole, which is frequently overestimated by echocardiography 1

Additional Cardiac Findings

Heart Sounds

• An early diastolic filling sound (S3) may be present in severe mitral regurgitation with significant volume overload 1, 3
• Normal intensity and splitting of S2 is typically preserved in mild MVP 1

Signs of Hemodynamic Severity

• Normal left ventricular and left atrial examination findings (no displaced apical impulse, no signs of chamber enlargement) suggest that severe chronic mitral regurgitation is unlikely, even if echocardiography suggests otherwise 1
• Signs of pulmonary congestion (rales, elevated jugular venous pressure) may be present in severe regurgitation with hemodynamic compromise 3

Dynamic Maneuvers

The click and murmur timing change predictably with maneuvers that alter left ventricular volume:

• 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
• Increased murmur intensity with Valsalva or standing helps distinguish MVP from innocent murmurs 1

Common Pitfalls in Physical Examination

Several examination errors can lead to misdiagnosis:

• Failing to examine in multiple positions (supine, sitting, standing) 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
• Assuming severe regurgitation based solely on murmur loudness without considering timing—a very late soft murmur may indicate only late systolic regurgitation with less severe hemodynamic impact 1, 4
• Overlooking the absence of diastolic filling sounds and clear lungs, which suggest only mild-to-moderate regurgitation despite other findings 1

Clinical Context Integration

The physical examination establishes critical pre-test probability that guides interpretation of echocardiography:

• When physical examination suggests severe MR (loud holosystolic murmur, early diastolic filling sound, signs of volume overload) but echocardiography shows only mild regurgitation, the echocardiogram likely underestimates severity due to technical limitations with eccentric jets 1
• When echocardiography suggests severe MR but physical examination shows only a very late soft systolic murmur with normal chamber findings, the echocardiogram likely overestimates severity by not accounting for the short duration of late systolic regurgitation 1
• The combination of click and murmur has the highest predictive value for echocardiographic confirmation of MVP (positive likelihood ratio 2.43), though one-third of patients may still have normal echocardiograms 5