Isolated Anomalous Right Coronary Artery Leading to Coronary Steal Syndrome

Most of the congenital anomalous coronary arteries are asymptomatic and diagnosed inc identally. But sometimes these may lead to angina pectoris, myocardial infaretion or sudden cardiac death. It is not a usual finding that a coronary artery supplying an organ other than the heart. Coronary collateral to the lung can rarely be observed in Takayasu's arteriris or in some congenital heart diseases. In this patient who had no atherosclerotic lesion, the sinus node branch of the right coro nary artery was supplying the middle lobe of the left lung caus ing symptoms and ischemia in the inferior wall on the myocardial perfusion scintigraphy, thus leading to coronary s tea! syndrome.