What are the physical exam findings of mitral valve stenosis?

Physical Examination Findings of Mitral Valve Stenosis

The classic physical examination findings of mitral valve stenosis include a loud S1, an opening snap, and a mid-diastolic rumbling murmur best heard at the apex with the patient in the left lateral decubitus position. 1

Auscultatory Findings

• First heart sound (S1): Accentuated/loud due to abrupt closure of the mitral valve from high left atrial pressure
• Opening snap (OS): High-pitched sound occurring shortly after S2, representing the sudden opening of the stiffened mitral valve
• Mid-diastolic murmur: Low-pitched, rumbling murmur best heard at the apex with the bell of the stethoscope
  • Increases in intensity with maneuvers that increase cardiac output (exercise, squatting)
  • May have presystolic accentuation in patients with sinus rhythm
  • Duration correlates with severity (longer duration = more severe stenosis)

Timing and Characteristics

• S2-OS interval: Inversely related to severity of stenosis and left atrial pressure
  • Shorter interval indicates more severe stenosis
• Murmur duration: Longer in more severe stenosis
• Murmur intensity: Does not reliably correlate with severity
• Presystolic accentuation: Present only in sinus rhythm, absent in atrial fibrillation

Associated Findings

• Irregular pulse: May indicate atrial fibrillation, which commonly occurs in mitral stenosis 1
• Parasternal lift: Suggests right ventricular hypertrophy due to pulmonary hypertension 1
• Diastolic filling complex: S3 gallop plus short diastolic murmur may be present 1
• Pulmonary findings: In advanced disease, signs of pulmonary hypertension including loud P2 component of S2

Variations by Severity

Mild Mitral Stenosis

• Mild valve doming during diastole
• Normal S1, may have early OS
• Short mid-diastolic murmur

Moderate Mitral Stenosis

• Rheumatic valve changes with commissural fusion
• Loud S1, clear OS
• Longer mid-diastolic murmur

Severe Mitral Stenosis

• Marked rheumatic valve changes
• Very loud S1, early OS
• Prolonged mid-diastolic murmur with presystolic accentuation (if in sinus rhythm)
• Signs of pulmonary hypertension may be present 1

Special Considerations

• In patients with severe pulmonary hypertension, the murmur may be soft or absent despite severe stenosis, with a single loud S2 and possible cyanosis/clubbing 1
• Atrial fibrillation eliminates the presystolic accentuation of the murmur
• Coexisting mitral regurgitation may mask some findings of mitral stenosis
• Echocardiography is essential for confirming the diagnosis when physical examination suggests mitral stenosis 1

Pitfalls in Physical Examination

• Tachycardia may obscure the opening snap and shorten diastole, making the murmur difficult to appreciate
• Soft murmurs may be missed without proper positioning (left lateral decubitus) and use of the bell of the stethoscope
• Elderly patients or those with severe pulmonary hypertension may have minimal murmurs despite significant stenosis
• Coexisting valvular lesions may confound the examination findings 1

When physical examination findings suggest mitral stenosis, echocardiography is the definitive test to confirm the diagnosis, assess severity, and evaluate for other associated cardiac abnormalities.