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©2013 UpToDate ® Print Email ACC/AHA guideline summary: Interventions used to alter the intensity of cardiac murmurs Respiration Right-sided murmurs typically increase with inspiration, while left-sided murmurs generally are louder during expiration. Valsalva maneuver Most murmurs decrease in length and intensity during the Valsalva maneuver. Two exceptions are the systolic murmur of hypertrophic cardiomyopathy (HCM), which usually becomes much louder, and the systolic murmur of mitral valve prolapse (MVP), which becomes longer and often louder. Following release of the Valsalva, right-sided murmurs tend to return to baseline intensity earlier than left-sided murmurs. Exercise Murmurs caused by blood flow across normal or obstructed valves (eg, mitral or pulmonic stenosis) become louder with both isotonic and submaximal isometric (handgrip) exercise. Murmurs of mitral (MR) and aortic regurgitation (AR) and ventricular septal defect (VSD) also increase with handgrip exercise. Positional changes Most murmurs diminish with standing due to reduced preload. However, the murmur of HCM becomes louder, and the murmur of MVP lengthens and often is intensified. Similarly, most murmurs become louder with prompt squatting (or usually passive leg raising), while the murmurs of HCM and MVP typically soften and may disappear. Post ventricular premature beat (VPB) or atrial fibrillation (AF) Murmurs originating at normal or stenotic semilunar valves increase in intensity during the cardiac cycle following a VPB or in the beat after a long cycle length in AF. In contrast, systolic murmurs due to atrioventricular valve regurgitation do not change, become softer (papillary muscle dysfunction), or become shorter (MVP). Transient arterial occlusion Transient external compression of both arms by bilateral cuff inflation to 20 mmHg greater than peak systolic pressure augments the murmurs of MR, VSD, and AR, but not murmurs due to other causes. Discussion of amyl nitrate has been removed since the use of amyl nitrate as a provocative agent is no longer recommended.

Transient arterial occlusion Transient external compression of both arms by bilateral cuff inflation to 20 mmHg greater than peak systolic pressure augments the murmurs of MR, VSD, and AR, but not murmurs due to other causes. Discussion of amyl nitrate has been removed since the use of amyl nitrate as a provocative agent is no longer recommended. Adapted from Bonow RO, Carabello BA, Chatterjee K, et al. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Circulation 2008;118:e523.