Involvement of the aortic valve cusps in discrete subaortic stenosis.

A review of 18 cases with discrete subaortic stenosis (DSS) revealed that involvement of the aortic valve cusps in the basic process was present in 16. In these 16 cases, extensions of fibroelastic tissue from the site of the DSS toward the base or superior to the base of one or more cusps were seen. In seven of the involved cases, deformity of a cusp was associated with these extensions. Valvular aortic insufficiency in cases with DSS might be caused by extensions of the fibroelastic tissue to the aortic cusps.