The anterior leaflet of the mitral valve is partly continuous through a fibrous membrane with the aortic valve. Lying immediately subjacent to the aortic valve, the mitral valve and its chordae may become secondarily infected in instances of primary aortic valvular bacterial endocarditis. Destructive changes of the anterior mitral leaflet or mitral chordae may lead to mitral insufficiency. The latter may dominate the functional and clinical pictures. In some instances, when infection is overcome, the clinical picture may appear to be that of primary mitral valvular disease.