Hypertrophic Cardiomyopathy

Abstract

Hypertrophic cardiomyopathy is generally considered to be congenital disorder characterized by myocardial fiber disarray, disproportionate hypertrophy of the interventricular septum (asymmetric septal hypertrophy, or ASH), and a tendency to left ventricular outflow tract obstruction produced by the hypertrophied septum and the systolic anterior motion of the anterior leaflet of the mitral valve. The condition occurs in the absence of cardiac or systemic disease capable of producing left ventricular hypertrophy. It has also been called idiopathic hypertrophic subaortic stenosis (IHSS) or hypertrophic obstructive cardiomyopathy (HCM). For a list of terms used to describe this condition, see Maron (1988) (some 75 at last count). Since the condition may exist in both obstructive and nonobstructive forms, the designation “hypertrophic cardiomyopathy” appears to be the most appropriate one at the present time. The condition was first described by Teare in 1958. Braunwald and associates’ classic paper (1964) identified the essential clinical features of this disease. The subject was reviewed recently by Maron, Bonow, and associates (1987).