A Unique Case of Anomalous Origin of the Left Main Coronary Artery From the Right Coronary Sinus

Anomalous origination and course of a coronary artery is a rare congenital finding, with clinical significance that varies depending on the vessel's anatomic trajectory. The risk of sudden cardiac death in affected patients is unpredictable and is largely determined by the relationship of the anomalous vessel to the great arteries. Anomalous origin of the left main coronary artery (LMCA) off the right sinus of Valsalva (RSV) is associated with increased risk of cardiac events, particularly when the vessel follows an inter-arterial or intramural course, which may result in dynamic compression resulting in myocardial ischemia. Here we present a case of a 63-year-old female with exertional chest pain and dyspnea whose initial non-invasive cardiac workup was unremarkable. Subsequent coronary angiography demonstrated an LMCA that arose from a shared ostium with the right coronary artery (RCA) in the RSV. Coronary computed tomography angiography (CTA) revealed an anterior and superior course relative to the great vessels. Given the benign anatomic course, the patient was managed conservatively without surgical intervention.