Anomalous Left Coronary Artery From the Right Sinus of Valsalva in a Patient Presenting with ST-Segment Elevation in Lead aVR: A Case Report

Anomalous coronary artery origins appear in roughly 1% of coronary angiograms, and up to 15% of syncope and sudden cardiac death events can be attributed to anomalous coronaries. Patients with an anomalous coronary artery arising from the opposite sinus may initially present with syncope and electrocardiographic findings of ischemia. We describe a case in which an adolescent male presented with exercise-induced angina and syncope, and his initial electrocardiogram (ECG) showed diffuse ST-segment depression with ST-segment elevation in lead aVR. Cardiac catheterization revealed there was no coronary ostium in the left coronary cusp, and the left coronary artery had an anomalous origin from the right cusp. The patient received urgent left internal mammary artery-to-left anterior descending artery coronary bypass and a saphenous vein graft to the ramus intermedius. After he underwent 6 months of medical therapy with β-blockade and angiotensin-receptor blockade, his left ventricular systolic function improved to low-normal level (left ventricular ejection fraction, approximately 50%). ST-segment elevation in lead aVR is strongly prognostic for left main or triple-vessel coronary artery disease. However, in patients who present with syncope and few other coronary artery disease risk factors, this ECG finding should be suggestive of an ischemic event caused by an anomalous left coronary artery. Early recognition of this pattern of clinical signs and ECG findings by an emergency physician could be critical for making the correct diagnosis and risk stratifying the patient for early coronary angiography and urgent surgical revascularization.