Single coronary artery anomaly angiography. (A) Aortogram (LAO 60° projection) demonstrating large right coronary artery with retrograde filling of the left circumflex and left anterior descending arteries with no left main coronary artery originating from aorta. (B) Selective coronary artery angiogram (PA 35° cranial projection) showing single right coronary artery (star). Large distal right coronary artery branch (arrow) retrogradely supplies left circumflex. Right coronary artery supplies posterior descending artery. Left anterior descending is filled retrogradely from a large collateral artery from a right coronary artery ventricular branch (triangle) that extends to the cardiac apex. Antegrade flow into left anterior descending from left circumflex is present. The middle left anterior descending segment (diamond) is hypoplastic. LAD, left anterior descending; RCA, right coronary artery.