Does Outflow Obstruction Exist in Hypertrophic Cardiomyopathy?

In this issue of the Journal, Pollick's report¹ focuses on the ability of disopyramide to reduce or eliminate the echocardiographic and hemodynamic signs of left ventricular “outflow obstruction” in a small number of patients with muscular subaortic stenosis. This study suggests that the negative inotropic actions of this drug may produce hemodynamic improvement and increase exercise tolerance by eliminating intraventricular gradients. Although this study was uncontrolled and its conclusions must be considered preliminary, it does raise an important question: Is left ventricular outflow truly obstructed in hypertrophic cardiomyopathy? Since the concept of a functional stenosis of the left ventricle.