Single coronary artery with subsequent coursing of right coronary artery between aorta and pulmonary artery: fractional flow reserve of the anomalous artery guiding the treatment.

A single coronary artery with an anomalous origin between the pulmonary artery and aorta is an unusual congenital anomaly. We present a 60 year old female patient with stable angina pectoris. Her coronary angiogram revealed that the right coronary artery originated from the left main stem and coursed between the great vessels. There was 90% stenosis in the left anterior descending coronary artery. We performed a fractional flow reserve study of both the anomalous origin artery and stenosed vessel. Fractional flow reserve study of the anomalous RCA did not reveal functional ischemia. We did not refer the patient to coronary artery bypass grafting but instead performed percutaneous coronary revascularization of the LAD. The patient is alive and has been free of symptoms during the 1 year follow-up.