Pseudoaneurysm of atrioventricular groove. A late complication of mitral valve replacement.

This report describes an unusual late complication of mitral valve replacement in which a false aneurysm of the atrioventricular groove produced compression on the circumflex coronary artery and myocardial infarction. The cause of this condition is not well explained, but its potential is present whenever there is early separation of the mitral anulus from the fibrous skeleton of the heart. Early hematoma formation resulting in frank perforation and hemorrhage has been reported, but late pseudoaneurysm formation after initial mitral valve replacement appears to be a rare occurrence.