Coexistence of hypertrophic obstructive cardiomyopathy and mitral annular calcification: proposed etiologic relationship.

A case of combined hypertrophic obstructive cardiomyopathy and mitral annular calcification is reported. The characteristic features of both entities were clearly demonstrated by thorough noninvasive examinations. It is proposed that the association of the two conditions is not coincidental but that mitral annular calcification, by narrowing of the left ventricular outflow tract, can result in the development of hypertrophic obstructive cardiomyopathy. Mitral annular calcification should possibly be added to the other causes of pressure overload of the left ventricle--such as hypertension and valvular or discrete subvalvular aortic stenosis--as a potential etiology of secondary hypertrophic obstructive cardiomyopathy.