97. What is Still's murmur?
Still’s murmur (a.k.a. “innocent murmur” or “functional murmur”) refers to a benign flow murmur across the aortic valve from high cardiac output and/or increased contractility (inotropy). Frequently seen in the pediatric population, Still’s murmur can disappear as the person moves into adolescence. No therapy is needed as Still’s murmur does not indicated any cardiac pathology.
Heard best at the left lower sternal border, Still’s murmur is crescendo-decrescendo and low pitched thus heard best with the bell of the stethoscope. The features that distinguish Still’s murmur from that of pathologic murmurs include the intensity (Still’s murmur will rarely be greater than II/VI, see grading systolic murmurs), the lack of other abnormal cardiovascular physical exam findings such as opening snaps or clicks, and the lack of cardiovascular symptoms (dyspnea, congestive heart failure).