Single coronary arteries: two cases with distinct and previously undescribed angiographic patterns.

Single coronary artery is a rare congenital anomaly, sometimes associated with myocardial ischemia. We present the clinical and angiographic features of two symptomatic patients with documented myocardial ischemia and with distinct and previously undescribed patterns of single right coronary arteries. These cases are new variants of the types R-I and R-II-A, in which the most probable mechanisms of ischemia are the insufficient blood supply, due to the long trajectories of the single arteries and the presence of underdeveloped vessels. Also, our second case presented with a fistulae from the LCX to the left ventricle, which is another determinant of myocardial ischemia.