A case of left main coronary artery to pulmonary fistula associated with vasospastic angina

Coronary artery fistulas (CAFs) are rare coronary anomalies. Among these, coronary artery-pulmonary artery fistulas can lead to myocardial ischemia through mechanisms such as coronary steal, stenosis, and vasospasm. We report a case of a 73-year-old male presenting with a coronary artery-pulmonary artery fistula and 75% stenosis of the right coronary artery. Despite negative findings for ischemia on myocardial scintigraphy and the absence of ST changes on a resting electrocardiogram (ECG), coronary steal syndrome was suspected following an exercise ECG that revealed diffuse ST depression. Surgical intervention to close the fistula was performed; however, the patient experienced intraoperative coronary spasms and ventricular fibrillation, necessitating the use of intra-aortic balloon pump and veno-arterial extracorporeal membrane oxygenation. The present case suggested that CAFs can be complicated by vasospasm, which may be overlooked at preoperative diagnostics. In patients with CAFs, careful evaluation regarding vasospastic angina should be done preoperatively.