Hypertrophic cardiomyopathy is a cardiac disorder characterized by asymmetric LV hypertrophy and impaired relaxation in diastole. Although most patients with hypertrophic cardiomyopathy do not have an increased LV outflow tract gradient at rest, many of them develop dynamic outflow tract obstruction with decreased filling and increased contractility. Under these conditions, as flow accelerates through the narrowed LV outflow tract, it creates drag, which pulls the anterior leaflet of the mitral valve toward the septum. This systolic anterior motion (SAM) of the anterior mitral leaflet leads to further outflow obstruction and mitral regurgitation.