Management of systolic anterior motion of the mitral valve: a mechanism-based approach.

Although the mechanism of systolic anterior motion (SAM) of the mitral valve is unknown, it is known to have a multifactorial pathophysiology. Echocardiographic analysis of the mitral leaflet revealed the step-wise progression of SAM, and intraventricular flow analysis revealed the contribution of drag force generated by the misled flow below the posterior leaflet. Although several diverse clinical features of SAM are already known, some key features need to be abstracted from among them to understand the regulation of SAM establishment. This paper reviews past articles that have investigated the mechanism of SAM and proposes a mechanism-based concept to provide insights for better comprehension of SAM recognition.