What physical examination maneuvers can be used to elicit the murmurs of mitral stenosis and mitral regurgitation?

Physical Examination Maneuvers to Elicit Mitral Stenosis and Mitral Regurgitation Murmurs

For mitral stenosis (MS), the murmur becomes louder with exercise (both isotonic and isometric handgrip), and left-sided murmurs are best heard during expiration; for mitral regurgitation (MR), the murmur increases with handgrip exercise and transient arterial occlusion, while decreasing with amyl nitrite inhalation. 1

Mitral Stenosis Maneuvers

The diastolic murmur of MS responds predictably to maneuvers that alter cardiac flow:

• Respiration: Listen during expiration - left-sided murmurs including MS are louder during expiration as venous return to the left heart increases 1, 2

• Exercise: Both isotonic and isometric (handgrip) exercise augment the MS murmur by increasing flow across the stenotic valve 1, 3. This is one of the most reliable maneuvers for MS

• Positioning:

  • Left lateral decubitus position brings the apex closer to the chest wall, making the low-pitched diastolic rumble easier to hear
  • The murmur becomes louder with brisk squatting (increases preload) 3
  • Standing diminishes most murmurs including MS 1

• Tachycardia phase after amyl nitrite: During the later tachycardia phase following amyl nitrite inhalation, the MS murmur increases 1, 3. This can distinguish MS from the Austin-Flint murmur of aortic regurgitation

• Post-premature beat or long R-R interval in atrial fibrillation: The MS murmur does NOT significantly change after a premature ventricular beat, unlike semilunar valve murmurs which increase 1

Mitral Regurgitation Maneuvers

The holosystolic murmur of MR has distinct responses that differentiate it from other systolic murmurs:

• Handgrip exercise: The MR murmur increases in intensity with sustained isometric handgrip (68% sensitivity, 92% specificity) 1, 4. This increases afterload and the regurgitant volume. This maneuver is highly specific for MR

• Transient arterial occlusion: Bilateral arm cuff inflation to 20 mmHg above systolic pressure augments the MR murmur (78% sensitivity, 100% specificity) 1, 4. This is one of the most specific maneuvers for MR

• Amyl nitrite inhalation: During the initial hypotensive phase, the MR murmur decreases (80% sensitivity, 90% specificity) 1, 4. This reduces afterload and thus regurgitant volume

• Respiration: The MR murmur is louder during expiration as a left-sided lesion 1, 2

• Valsalva maneuver: The MR murmur decreases during the strain phase due to reduced preload 1. This helps distinguish it from hypertrophic cardiomyopathy, which increases

• Positional changes:

  • Squatting increases the MR murmur (increases preload and afterload) 1, 3
  • Standing diminishes the murmur 1
  • Passive leg raising produces similar effects to squatting 1

• Post-premature beat or atrial fibrillation: The MR murmur does NOT change or may diminish in the beat following a premature ventricular contraction or after a long R-R interval 1, 5. This is a key differentiating feature from aortic stenosis, which increases

Clinical Pearls and Pitfalls

Common pitfall: Confusing MR with ventricular septal defect - both have parallel responses to maneuvers. However, MR and VSD can be differentiated from other systolic murmurs by their specific response pattern to handgrip and arterial occlusion 4.

Key distinction: No single maneuver is 100% accurate, but combining responses provides high diagnostic accuracy. The combination of handgrip augmentation and transient arterial occlusion augmentation is highly specific for MR 4.

Important caveat: In mitral valve prolapse with late systolic MR, the click-murmur complex moves earlier in systole with standing/Valsalva (decreased LV volume) and later with squatting (increased LV volume) 1, 2. This is the opposite of most murmurs.