Michael J. Rosenberg, MD: From the Department of Cardiology, Advocate Lutheran General Hospital, Park Ridge, Illinois.

A 67-year-old man with positive results on a stress myocardial perfusion test was found to have isolated anomalous origin of the left anterior descending coronary artery from a separate coronary ostium of the right sinus of Valsalva. This anomalous artery was not stenotic and coursed over the anterior free wall of the right ventricle, in front of the pulmonary artery. It did not appear to have an intra-arterial or intramyocardial course.