Asymptomatic congenital arteriovenous fistula arising from left circumflex artery draining into distal part of right pulmonary artery diagnosed at the 7th decade of life

Congenital coronary arteriovenous fistula (CAVF) is a rare and its incidence during coronary angiogram is estimated about 0.1% to 0.2%. In 1908 Maude Abbott described the first CAVF. Majority of coronary artery fistulas are identified during echocardiography or coronary arteriography. They are usually small and clinically difficult to detect. Most of them resolve spontaneously and does not cause any symptoms. A large coronary fistula is usually 3 times bigger the size of a coronary artery. We report a case of congenital arteriovenous fistula arising from left circumflex artery communicating to one of the branches of right pulmonary artery, having normal coronaries. This 77-year-old female with positive stress myoview & multiple risk factors, presented with paroxysmal atrial fibrillation. Asymptomatic CAVF up to the 7th decade of life makes this case rare and unique.