Discrete subaortic stenosis associated with congenital valvular aortic stenosis--a diagnostic challenge.

Discrete subaortic stenosis has only rarely been reported in association with congenital valvular aortic stenosis. The valvular lesion may obscure the subaortic stenosis or may be obscured by it. Our experience with seven such cases (10% of our 71 patients with discrete subaortic stenosis) is reported and the diagnostic problems are discussed. In six cases the discrete subaortic stenosis was membranous and in one it was a fibromuscular tunnel. Two patients had associated coarctation of the aorta, two had aortic insufficiency, and one had a ventricular septal defect. An important clinical clue to the diagnosis was an ejection systolic click, which was found in four patients. Four patients were accurately diagnosed at cardiac catheterization. Two patients, in whom cross-sectional echocardiography (2DE) was performed, were accurately diagnosed by it.