On systolic murmurs and cardiovascular physiological maneuvers.

Physiological principles that directly apply to physical diagnosis provide opportune occasions to bring basic science to the bedside. In this article, we describe the effect of cardiac maneuvers on systolic murmurs and how physiological principles apply to the explanation of the changes noted at the bedside. We discuss the effect of Valsalva, squatting, and hand grip maneuvers on different physiological parameters influencing preload, afterload, chamber dimensions, and pressure gradients. The clinical manifestations noted during the aforementioned maneuvers are described in common cardiac conditions responsible for the production of certain systolic murmurs.