Septal course of the left main coronary artery from right aortic sinus and ventricular tachycardia.

A 42-year-old man with resistant ventricular tachycardia was found to have an anomalous origin of the left main coronary artery from the right aortic sinus that pursued an intramyocardial course through the ventricular septum. The tachycardia resolved after coronary artery bypass graft to otherwise normal left anterior descending and circumflex coronary arteries. Septal course of an anomalous left main coronary artery from right aortic sinus should not always be considered benign.