Myocardial infarction and coronary ectasia in idiopathipc mitral valve prolapse syndrome.

Angina pectoris and myocardial infarction occurred in two patients with idiopathic mitral valve prolapse in the absence of atherosclerotic coronary artery disease. Instead, both patients showed the presence of coronary artery ectasia on cineangiography. The anatomic localization of ectasia corresponded with segmental derangement of left ventricular wall motion. Repeated thromboemboli from ectatic vessels and/or locally liberated platelet metabolites were considered the probable mechanism of these symptoms.