A Rare Case of Single Coronary Artery With Pulmonary Artery Fistula

Background: Single coronary artery is a rare congenital anomaly. Its coexistence with coronary artery fistula is exceedingly uncommon. Case Summary: A 61-year-old woman with no cardiovascular risk factors underwent her first cardiological evaluation after incidental detection of atrial fibrillation. Imaging revealed a markedly dilated single coronary artery originating from the left coronary sinus, with a large fistula to the pulmonary artery trunk. Despite atrial enlargement and moderate mitral and tricuspid regurgitation, the patient was asymptomatic with preserved ventricular function. A conservative management strategy with close follow-up was adopted after multidisciplinary discussion. Discussion: Management of rare coronary anomalies should be individualized. While surgery is recommended in symptomatic patients or those with evidence of ischemia, asymptomatic individuals may be managed conservatively; however, signs of adverse cardiac remodeling should prompt early reconsideration of intervention. Take-Home Message: Conservative follow-up may be appropriate in asymptomatic patients with complex coronary anomalies, but progressive structural changes warrant timely reassessment of surgical options.