Anomalous Origins of Coronary Arteries
Normally the right and left coronary arteries arise from the corresponding right and left coronary sinuses, respectively. Coronary arteries typically arise from the coronary sinuses closest to the pulmonary artery. Embryologically, the coronary arteries develop in the epicardial atrioventricular and interventricular grooves and then connect to the aorta late in their development. There is a wide spectrum of where along the coronary artery ostium their origin can occur on the path of the coronary sinus. The coronary ostium may normally arise up to 5 mm above the aortic sinotubular junction. There is also a wide range in the number of coronary arteries that may arise. Origins include a single coronary artery, two origins from the same sinus, multiple origins from multiple sinuses, oblique origins frequently seen with an intramural course, and high origins along the sinotubular junction. Right or left coronary arteries may arise from the contralateral coronary artery as well. These anomalies are briefly discussed here and then more fully examined in the chapter on coronary artery course anomalies (see Chap. 5). Coronary origins may be normal but have an unusual appearance in infants and children with congenital heart disease. We will review a few of these cases in this chapter.