Sudden cardiac arrest: associated with anomalous origin of the right coronary artery from the left main coronary artery.

Anomalous origin of the coronary artery from the opposite sinus of Valsalva and a course of that artery between the ascending aorta and the pulmonary artery is a rare congenital anomaly. It can cause myocardial ischemia, syncope, and sudden cardiac death in young people. Herein, we report the case of a 24-year-old man who was brought to our hospital after cardiac arrest due to ventricular fibrillation. Emergent coronary angiography revealed that the left coronary artery was normal; however, the right coronary artery originated at the left sinus of Valsalva. After admission, the patient was treated with mild therapeutic hypothermia for 48 hours and had a favorable neurologic recovery. Subsequent 16-slice multidetector computed tomography revealed that the right coronary artery arose from the left main coronary artery, took an intramural course, and was severely compressed between the ascending aorta and the pulmonary artery. The patient underwent direct implantation of the anomalous artery into the correct aortic sinus. Histologic specimens from the proximal end of the right coronary artery showed an intramural segment with intimal fibrous thickening, fragmentation and random arrangement of the elastic fiber, degeneration of the medial smooth-muscle cells, and an increase in the medial stromal substance. Postoperatively, repeat coronary angiography with provocation testing for coronary spasm revealed no myocardial ischemic change. The patient recovered uneventfully. We found that cardiac multidetector computed tomography was useful in evaluating the cause of the sudden cardiac arrest, identifying the anomalous coronary artery, and helping to guide the surgical decisions.