Coronary fistula is the most frequent hemodynamically significant congenital malformation of coronary circulation. It can originate from any of the three major coronary arteries and drain in all the cardiac chambers and great vessels.
A 28 year-old woman was referred for correction of patent ductus arteriosus. She reported history of few episodes of dyspnea on exertion since several years ago. On physical examination a continuous murmur could be heard mainly at the lower left sternal border. Transesophageal echocardiography showed dilated origin of left main and left circumflex arteries with a continuous flow to the right atrium. Spiral CT coronary angiography revealed an aneurysmalleft circumflex artery connecting with the right ventricle. Left system seemed to be dominant. Surgery was done in order to excise the distal part of LCX.