Echocardiographic evaluation of the five-chamber heart: a rare congenital coronary anomaly.

Coronary artery fistulas are rare congenital anomalies that usually drain into one of the cardiac chambers or veins. The current patient was found to have a distinctly unusual anatomic picture, with a fifth cardiac chamber appearing at the cardiac apex. This proved to be the drainage site for a large coronary artery fistula originating in the left anterior descending coronary artery. The anatomic relations and blood flow patterns were demonstrated with transthoracic and transesophageal echocardiography.