What type of murmur is typically associated with hypertrophic obstructive cardiomyopathy?

Systolic murmurs are typically associated with hypertrophic obstructive cardiomyopathy (HOCM) due to the underlying mechanism of the condition. HOCM involves the thickening of the heart muscle, specifically the interventricular septum, which can obstruct blood flow from the left ventricle into the aorta during systole. This obstruction often results in a dynamic outflow tract obstruction, especially during exertion or certain body positions.

The resultant murmur is usually described as a harsh, systolic ejection murmur that may increase in intensity with maneuvers that decrease preload (such as standing or Valsalva maneuver) and may decrease with maneuvers that increase preload (like squatting). The characteristics of a typical systolic murmur associated with HOCM include being heard best at the left sternal border and may also radiate towards the carotids, mimicking aortic stenosis.

This understanding of the hemodynamics involved in HOCM is crucial for recognizing the clinical manifestations that accompany it, including the distinct sound of the murmur heard upon auscultation.