This chapter focuses on the management of coronary artery anomalies in patients without other hemodynamically significant heart defects. Although most coronary artery anomalies are of intellectual interest only, there are a few that are clinically significant as they may result in myocardial ischemia, left ventricular dysfunction, and sudden death. The clinically significant anomalies that we will discuss in this chapter are: anomalous origin of a coronary artery from the pulmonary artery, anomalous coronary artery that courses between the aorta and the pulmonary artery, and coronary artery fistulae.
Normally, two coronary arteries arise from separate ostia in the right and left aortic sinuses of Valsalva. The left main coronary artery (LMCA) originates from the left sinus and usually bifurcates into the left anterior descending (LAD) coronary artery and left circumflex coronary artery. The LAD courses in the anterior interventricular groove while the left circumflex coronary artery runs in the left atrioventricular groove. The right coronary artery (RCA) originates anteriorly from the right aortic sinus, runs along the right atrioventricular groove, and usually terminates as the posterior descending artery.
The coronary artery ostia are usually centrally located in the appropriate sinus of Valsalva. However, the ostium may be eccentrically located in some individuals, with the ostium arising close to a valve commissure. The coronary ostia may have a “high takeoff” from the tubular aorta above the sinotubular junction, which is usually benign. It is important to be aware of this anomaly if one needs an aortic valve replacement or requires an aortotomy for another reason, as the coronary artery can be transected if not recognized prior to surgery. When both coronary arteries arise from the same aortic sinus with either a single ostium or two separate ostia (Table 83-1), the anomaly is usually benign if the anomalous vessel courses posterior to the aorta or anterior to the pulmonary artery. However, if either the anomalous LMCA or RCA courses between the two great vessels, this may lead to myocardial ischemia and sudden death.
Table 83-1:Origin of Both Coronary Arteries from One Sinus |Favorite Table|Download (.pdf) Table 83-1: Origin of Both Coronary Arteries from One Sinus
Left main coronary artery originates from right sinus of Valsalva (either from right coronary artery or separate ostia).
Left main coronary artery courses anterior to pulmonary artery.
Left main coronary artery courses through interventricular septum.
Left main coronary artery courses between aorta and pulmonary artery.
Left main coronary artery courses posterior to aorta.
Rarely the left anterior descending coronary or left circumflex coronary artery alone may originate from the right sinus.
Single left main coronary artery arises from the left sinus and bifurcates into the left anterior descending coronary and left circumflex coronary arteries. The left circumflex coronary artery crosses the crux and continues as the right coronary artery.
Single right coronary artery from right sinus, which crosses crux, continues ...