Sudden cardiac arrest during diagnostic workup: a rare case of high-risk interarterial left anterior descending artery anomaly

Coronary artery anomalies are anatomical abnormalities involving abnormal origin, course, or termination of any of the three main epicardial arteries. These abnormalities may go unnoticed during a person’s lifetime; however, they can occasionally present acutely or chronically as angina, myocardial infarction, cardiac arrhythmias, or even sudden cardiac death. A 65-year-old woman with angina and stress-induced ST-segment depression in a treadmill test. Coronary angiography showed the absence of the left main coronary artery with separate origins of the left anterior descending artery and circumflex artery. During a planned cardiac computed tomography angiography scan, the patient presented with cardiac arrest secondary to ventricular fibrillation and was hospitalized. A high-risk interarterial course of the left anterior descending artery was identified, and coronary artery bypass grafting with surgical mobilization of the left anterior descending artery along its interarterial course, where it was ligated with a hemoclip prior to the first septal branch to prevent competitive flow. The postoperative course was uneventful. When this rare anomaly is detected in the population, clinicians must identify the risk of fatal events and determine appropriate management based on age, symptoms, vascular anatomy, and the presence of arrhythmia.