A Rare Case of Giant Aneurysm of the Right Coronary Artery with Right Coronary Artery to Coronary Sinus Fistula

Background: Coronary artery aneurysms are rare, localized, abnormal dilations of the artery. The combination of coronary artery aneurysm and coronary artery to coronary sinus fistula is even more rare. Case Presentation: This report presents a case of a giant right coronary artery aneurysm and a right coronary artery to coronary sinus fistula in a 55-year-old Indian female who presented with chest pain and exertional dyspnea that had been increasing over a six-month period and became severe one week prior to admission. The referral diagnosis was severe aortic regurgitation with a ruptured sinus of Valsalva; however, diagnostic imaging at our center revealed a 100 mm aneurysm of the proximal to mid segment of the right coronary artery with ectasia of the distal right coronary artery and a fistulous connection at the level of its ostium. The patient underwent successful aneurysm resection, fistula closure and coronary artery bypass grafting using great saphenous vein graft to the posterior descending artery. Conclusions: This case highlights the importance of including giant coronary artery aneurysms in the differential diagnosis for patients presenting with chest pain, exertional dyspnea, and a cardiac mass. It also emphasizes the need to investigate for coronary fistulae as a significant associated finding and underscores the diagnostic challenges posed by this complex pathology.