Single coronary artery arising from the right sinus of Valsalva

Single coronary artery (SCA) is a rare congenital anomaly in which the entire coronary system arises from a solitary ostium. A 65-year-old male with a history of diabetes mellitus, hypertension, and hyperlipidemia was admitted with exertional angina pectoris of new onset. His physical examination, hemogram, thyroid function tests, chest X-ray, electrocardiogram, and transthoracic echocardio-gram were normal. In treadmill exercise test, the patient could not reach submaximal heart rate due to fatigue. Coronary angiography revealed an SCA arising from the right sinus of Valsalva (type R-IIA). The left coronary artery (LCA) coursed anteriorly in front of the right ventricular outflow tract and gave off branches for the left anterior descending and left circumflex (LCx) arteries. A mild diffuse nonobstructive atherosclerotic lesion was also detected in the LCx. The entire SCA and the anterior course of the LCA in relation to the great vessels were further displayed by 16-row multislice computed tomography. The atherosclerotic lesion was not eligible for percutaneous intervention and the patient was scheduled for medical therapy with recommendation of risk factor modification.