Anomalous origin of the circumflex coronary artery--two case reports.

As shown in many series, congenital coronary artery anomalies are found in 0.6 to 1.5% of patients undergoing coronary angiography. Various types of coronary anomalies have been described, many involving the circumflex artery. The second most common anomaly is of the circumflex arising from the right sinus of Valsalva, while origin in the right coronary artery is also frequent. The most common anomaly is absence of the left main coronary artery, the anterior descending and circumflex arteries originating separately in the left coronary sinus. Such anomalies are usually benign, although earlier and more aggressive atherosclerosis is more likely than in normal coronaries and myocardial ischemia can result. Although rare, this can manifest as sudden death. Conventional coronary angiography may be unable to determine the three-dimensional course of the anomalous vessel. The development of multislice computed tomography and its application to cardiac imaging mean that it is now possible to visualize the coronary arteries non-invasively and to obtain more accurate information on their proximal course. We present two cases of congenital anomaly of the circumflex coronary artery diagnosed with the aid of multislice computed tomography.