Henry Ford Hospital Medical Journal


The purpose of this study is to explore the value of intracardiac sound recordings for the verification of subaortic stenosis. Intracardiac sound was measured in ten patients with subaortic obstructions. Seven had idiopathic hypertrophic subaortic stenosis, two had a subvalvular membrane, and one had a subvalvular tunnel. In each patient, a systolic murmur was recorded within the left ventricle distal to the obstruction. The murmur was of lower amplitude distal to the aortic valve, and it was of even lower amplitude or absent proximal to the obstruction. In the presence of entrapment, no intraventricular murmur occurred although an apparent subvalvular pressure gradient was observed. The identification and localization of the maximal intensity of a systolic murmur in the ventricular outflow tract may assist in the verification of a subvalvular obstruction and help distinguish between artifactual pressure gradients and gradients indicative of subvalvular stenosis.