Venturi effect

The Venturi effect is described as a decrease in pressure when blood flows through a stenosis at a high velocity. This relates to the hemodynamics in hypertrophic obstructive cardiomyopathy (HOCM). In HOCM, the increased velocity in the left ventricular outflow tract decreases pressure in this region causing the anterior leaflet of the mitral valve to be pulled in that direction. This is called “systolic anterior motion” of the mitral valve or SAM. Mitral regurgitation can result and contribute to congestive heart failure symptoms in the setting of HOCM.