Transcatheter management of a complex aneurysmal coronary cameral fistula mimicking as five-chambered heart

Coronary cameral fistulas (CCF) are uncommon congenital heart anomalies, accounting for 0.2%-0.4% of cases. The occurrence of coronary artery aneurysms alongside these fistulas is even rarer, and they are associated with risks, including aneurysmal rupture, clot formation, and endocarditis. This report highlights a unique case of a five-chambered heart, where the right coronary artery anomalously drains into the interventricular septum, forming an additional fifth chamber. We demonstrated a complex aneurysmal CCF, which was initially masqueraded by a coexisting atrial septal defect (ASD). The report describes the diagnostic challenges and a successful transcatheter closure of this complex fistula, while also addressing the associated ASD.