Silent myocardial infarction complicated by asymptomatic ventricular septal defect and deferred rupture of left ventricular pseudoaneurysm.

Patients with a postinfarction ventricular septal defect or ruptured left ventricular pseudoaneurysm usually present with sudden cardiogenic shock or cardiac tamponade, respectively. We report the case of a 59-year-old man who had a silent myocardial infarction followed by an asymptomatic ventricular septal defect, both of which remained undiagnosed until the patient experienced a 2nd myocardial event 1 month later. This 2nd event was possibly a new infarction accompanied by left ventricular pseudoaneurysmal development and exsanguination, but not by tamponade. On admission, an electrocardiogram showed changes suggesting the presence of an old anterior myocardial infarction. Echocardiography revealed a ventricular septal defect and moderate pericardial perfusion, while left ventriculography disclosed a large extraventricular sac protruding from the anterior wall. The patient also had severe 2-vessel coronary artery disease, as indicated by angiography. Surgery confirmed a postinfarction ventricular septal defect and an exsanguinating pseudoaneurysm, highly circumscribed and well apart from the septal defect, involving the anterior wall of the left ventricle. The patient made good recovery following resection of the aneurysm, repair of the septal defect, and placement of 2 bypass grafts.