Background: Coronary arterial fistula, or arterio-venous malformation (AVM), is a connection between the coronary tree and a cardiac chamber or great vessel, having bypassed the myocardial capillary bed. Known complications from coronary artery fistulas may include “steal” from the adjacent myocardium, resulting in myocardial ischemia.
Case Report: We report the case of a 57-year-old Hispanic woman with abnormal preoperative electrocardiogram (ECG) and symptoms of dyspnea on exertion, who underwent a stress echocardiography demonstrating inferior distribution hypokinesis at peak exercise. Coronary computed tomography angiography (CCTA) demonstrated a venous fistula connecting the coronary sinus (CS) with the distal portion of the left anterior descending artery (LAD), occupying the territory of a left posterior descending artery (L-PDA) and corresponding in distribution with the patient’s stress-induced wall motion abnormalities.
Conclusions: Anomalous left anterior descending artery to coronary sinus fistula with associated ischemia is a rare clinical dilemma with limited experience of success with either surgical or medical options.

Keywords: Arteriovenous Fistula, left anterior descending coronary artery fistula, computed tomography, coronary sinus