Coexisting right and left hypertrophic subvalvular stenosis and fixed left ventricular outflow obstruction due to aortic valve stenosis.

A case of fixed left ventricular outflow tract obstruction due to aortic valve stenosis coexisting with right- and left-sided subvalvular hypertrophic stenosis is documented with hemodynamic data, angiograms, echocardiograms and findings at surgery. Histologic examination of the septal muscle with light and electron microscopy revealed hypertrophy of the muscle but none of the characteristics of idiopathic hypertrophic subaortic stenosis. Septal hypertrophy with subvalvular obstruction can occur secondary to left ventricular pressure overload due to fixed left ventricular outflow tract obstruction and is not always the chance occurrence of two separate diseases.