hypertrophic subaortic stenosis, a form of hypertrophic cardiomyopathy, in which the left ventricle is hypertrophied (commonly with disproportionate involvement of the interventricular septum) and the cavity is small. It is marked by obstruction to left ventricular outflow. Also called idiopathic hypertrophic subaortic stenosis, muscular subaortic stenosis.
