Right Coronary Artery–Right Atrial Fistula with Left-to-Right Shunt: A Rare Case Managed by Surgical Closure

Abstract

Background and purpose: Coronary artery fistula (CAF) is a rare congenital anomaly, with an estimated prevalence of 0.002% in the general population and accounting for approximately 14% of all coronary artery anomalies. While many cases remain asymptomatic and are incidentally discovered, others can present with nonspecific symptoms or lead to serious complications such as myocardial ischemia, heart failure, pulmonary hypertension, or aneurysmal dilatation. Recognizing and managing hemodynamically significant fistulas early is crucial to prevent long-term cardiopulmonary consequences.

Methods: A 54-year-old female presented with a 10-month history of exertional dyspnea, palpitations, and intermittent chest pain. Her past medical history was unremarkable. Electrocardiography revealed normal sinus rhythm, and cardiac biomarkers were within normal limits. Transthoracic echocardiography demonstrated preserved left ventricular function, elevated right ventricular systolic pressure (RVSP) of 55 mmHg, and a Qp/Qs ratio of 1.6, consistent with a left-to-right shunt. Further evaluation with computed tomography angiography identified a right coronary artery fistula draining into the right atrium. Coronary angiography confirmed the anatomy and guided multidisciplinary discussion on management options, including percutaneous versus surgical closure.

Results: Given the size of the fistula and its hemodynamic impact, surgical closure was selected as the definitive treatment. The procedure was successfully performed without complications. At two-month follow-up, the patient reported complete resolution of symptoms. Repeat echocardiography showed a reduction in RVSP to 30 mmHg, with no residual shunt or recurrence.

 Conclusion: This case underscores the importance of early detection and timely surgical intervention in coronary artery fistulas with significant shunting. Left untreated, such lesions may result in progressive right heart failure or irreversible pulmonary hypertension. Surgical closure remains an effective and durable solution in preventing these complications.