Mitral valve prolapse due to coronary artery disease.

Controversy exists concerning the etiologic role of coronary artery disease in the prolapsing mitral valve leaflet syndrome. A 35 year old man with progressive coronary artery disease is described. Auscultation before and after his first myocardial infarction revealed only a fourth heart sound; subsequently left ventricular cineangiography demonstrated normal anatomy and function of the mitral valve, despite extensive wall motion abnormalities. Six months later he experienced another myocardial infarction after which the typical mid-systolic click, late systolic murmur of mitral valve prolapse developed. A second left ventricular cineangiogram at this time revealed mid-systolic mitral valve prolapse and mitral regurgitation. This patient's course indicates that myocardial damage from coronary artery disease can cause mitral valve prolapse in patients with preexisting redundant mitral valve tissue.