Blinded study of bedside maneuvers to diagnosis systolic murmurs in 50 pts aged 6-85, ALL WITH DOCUMENTED VALVULAR DISEASE; there was 87% concordance between examiners on whether maneuvers increased, decreased, or didn't change intensity of murmurs. Diagnosis made by cardiac cath or echo. (NEJM 318:1572, 1988)
- All murmurs from right-sided lesions increased in intensity with inspiration and decreased during expiration. These changes were 100% sensitive and 88% specific for right-sided as opposed to other lesions
- Most left-sided murmurs decreased or no change with inspiration and increased or no change with expiration
- Physiologic explanation: increased venous return with inspiration increases R-heart but has little effect on L-heart filling
II. Valsalva maneuver (hold for 20sec; listen just before end of the strain phase)
- Increases 65% of the time with hypertrophic cardiomyopathy; decreased 30% of the time; Increased intensity 65% sensitive and 96% specific for hypertrophic cardiomyopathy as opposed to other lesions
- Most other murmurs decreased intensity during Valsalva
- Physiologic explanation: murmur intensity increases with decreased LV volume because of increased proximity of septum and mitral valve; decreased venous return with Valsalva
III. Passive leg elevation (straight leg raise to 45 degrees; listen after 15-20sec)
- Decreases 85% of the time with hypertrophic cardiomyopathy; decrease with leg raise 85% sensitive and 91% specific for hypertrophic cardiomyopathy as opposed to other lesions
- Other lesions mostly no change or increase in intensity with leg elevation
- Physiologic explanation: see II. C.
IV. Squatting to standing (squat for > 30sec then rapidly stand; listen during 1st 15sec of standing)
- Increases 95% of the time with hypertrophic cardiomyopathy; increase with this maneuver is 95% sensitive and 84% specific for hypertrophic cardiomyopathy as opposed to other lesions
- Other lesions tended to decrease or not change with this maneuver
- Physiologic explanation: see II.C.
V. Transient arterial occlusion (BP cuff around both upper arms, simultaneously inflated to 20-400mm Hg above systolic BP; listen after 20sec)
VI. Inhalation of amyl nitrite (one 0.3ml ampule; pt takes 3 rapid, deep breaths; listen 15-30sec after inhalation; don't do with critical aortic stenosis & others who can't tolerate sudden drop in BP!)
VII. Isometric handgrip (listen after 1 min of maximal contraction)
- Increases about 70% of the time with mitral regurgitation and VSD; though decreases (1) in 20% of each
- Decreases 85% of the time with hypertrophic cardiomyopathy
- No consistent effect (mostly no change or decrease) with aortic stenosis or right-sided murmur
- Physiologic explanation: this maneuver has multiple effects, including increased venous return, heart rate, cardiac output, and arterial pressure.
VIII. Muller maneuver (making forceful effort to inhale with glottis closed; the opposite of Valsalva): no consistent difference among its effects on different types of murmurs; tended to decrease intensity of all.