A Rare Case of Single Coronary Artery With Pulmonary Artery Fistula

Single coronary artery is a rare congenital anomaly. Its coexistence with coronary artery fistula is exceedingly uncommon. 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. 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. Conservative follow-up may be appropriate in asymptomatic patients with complex coronary anomalies, but progressive structural changes warrant timely reassessment of surgical options.