Congenital right coronary artery aneurysm causing myocardial infarction, pseudoaneurysm formation, and right atrial compression.

We present a case of a young woman with symptoms of acute myocardial infarction and found to have a nonatherosclerotic coronary aneurysm of the right coronary artery, which ruptured and formed a pseudoaneurysm. The pseudoaneurysm was sufficiently large that it mimicked an atrial mass on diagnostic imaging modalities. With the attendant risk of further rupture and compression of the heart chambers, the patient underwent successful resection of the aneurysm and pseudoaneurysm with single vessel bypass surgery.