Left circumflex coronary arteriovenous fistula presenting as acute coronary syndrome

Coronary arteriovenous fistula (CAVF) is a rare congenital anomaly that is seen in 0.1-0.2% of coronary angiograms. A 79-year-old man with no risk factors for coronary artery disease, presented with unstable angina and normal clinical examination. Coronary angiogram revealed a large left circumflex coronary artery with multiple aneurysms exiting into right atrium. Although coil embolization was feasible, he was managed conservatively as he responded to medications. This case shows that large CAVF can be asymptomatic up to the 7th decade of life, manifest as acute coronary syndrome, can present without any murmur on auscultation, and medical management can be effective.