Mural vegetations at the site of endocardial trauma in infective endocarditis complicating idiopathic hypertrophic subaortic stenosis.

In two patients infective endocarditis developed as the primary manifestation of idiopathic hypertrophic subaortic stenosis. Infected vegetations were present on the mitral and aortic valves. In addition, bacterial vegetations were observed on the septal endocardium at the site of contact between the mitral valve leaflet and the hypertrophic septum. Thus, chronic endocardial trauma, a common finding in idiopathic hypertrophic subaortic stenosis, may provide a fertile nidus for the development of bacterial vegetation.