Abstract
We describe an extreme rare case of high commissural anomalous origin of left circumflex coronary artery (LCX) with angiographic alpha loop suggestive of retroaortic course (Figure 1) where LCX after originating high from the commissure turns one-half turn behind the aorta to come anteriorly to run in the left atrioventricular groove. This acute turn of alpha loop predisposes to myocardial ischemia during exertion. A 22-year-old male, nondiabetic, nonhypertensive, nonsmoker, normolipidemic without any family history of coronary artery disease presented to the cardiology outpatient department with effort angina Canadian cardiovascular Society (CCS) class II since last 6 months. Serum chemistries, electrocardiogram, and echocardiography were within normal limit. Treadmill test was strongly positive for provocative ischemia and he was subjected for right trans radial coronary angiogram which revealed left main coronary artery giving rise to only left anterior descending coronary artery (LAD) and right coronary artery (RCA) arising from the right coronary sinus (Figure 2). Angiographic scanning from left coronary sinus toward right coronary sinus revealed high commissural posterior origin of LCX with angiographic alpha loop suggestive of retroaortic course (Figure 1). High commissural origin of LCX with angiographic alpha loop has not been illustrated in literature so far. Our case is unique and first description of high commissural origin of LCX with an angiographic alpha loop where the alpha loop was the cause of provocative coronary ischemia without the presence of obstructive coronary artery disease. As clearly seen in the above angiogram after originating high in commissure between right and noncoronary sinus, the artery goes down and takes a right angle forward turn or bend, crosses the hinge between left and noncoronary sinus, and come anteriorly to lie in the left atrioventricular grove and this α loop produces provocative coronary ischemia. The retroaortic portion of LCX giving a left atrial branch is clearly seen in angiogram (Figure 1). In the angiographic image (Figure 1), LCX is arising high from the commissure between the right coronary and noncoronary sinus, going downward after origin, giving rise to the left atrial branch, taking a 90-degree forward turn making an angiographic alpha (α) loop to cross the commissure between left coronary and noncoronary sinus, then lie in the left atrioventricular groove being widely separated from the aortic root. Doty 1 described an intraoperative similar origin of anomalous origin of LCX from a rudimentary commissure between right and noncoronary sinus, described the retroaortic course but it was not high commissural origin and angiographic alpha loop was not described for the same. Doty described that the retroaortic anomalous LCX was adherent to the noncoronary sinus aorta. They were treating a bicuspid aortic valve for which they performed the Ross procedure with anastomosis of the anomalous retroaortic LCX to the noncoronary sinus of the pulmonary autograft. Our case is unique and first angiographic illustration of high commissural origin of LCX from hinge of right and noncoronary sinus with a retroaortic α loop well illustrated in coronary angiogram, causing provocative coronary ischemia in a young patient. We managed the patient with adequate beta blocker, that is, metoprolol 50 mg twice daily with antianginal ranolazine and he was doing well in follow-up.
High Commissural Origin of Anomalous LCX With α Loop of Retroaortic Course.
LMCA Giving Rise to Only LAD and RCA From Right Coronary Sinus.
