Aneurysm of the left atrial appendage.

We present the case of a 33-year-old woman with atrial tachyarrhythmias and chest pain. The transthoracic echocardiography demonstrated an intrapericardial liquid mass confirmed as an aneurysm of the left atrial appendage by a nuclear magnetic imaging study. Aneurysmectomy was performed with the assistance of cardiopulmonary bypass with a bilateral submammary skin incision and subsequent median sternotomy. The patient had an uneventful postoperative course. We suggest aneurysmectomy aided by cardiopulmonary bypass as a safer method of treatment for this rare cardiac anomaly.