Fistulous communication between the circumflex artery and right atrium: Diagnostic imaging and surgical repair

A coronary artery fistula (CAF) is an aberrant connection between a coronary artery and heart chamber or major thoracic vessel that bypasses capillary beds and results in a left-to-right shunt. CAFs commonly result from congenital abnormalities but may be acquired via iatrogenic mechanisms, affecting approximately 0.002% of the general population and accounting for only 0.1% of coronary anomalies [1]. While the origin and termination sites of CAFs vary, those that arise from the left circumflex artery (LCX) are the rarest [1,2]. Treatment of CAFs is controversial. Current strategies include medical management, trans-catheter approaches, and surgical correction. The following case study discusses a symptomatic patient who was diagnosed with a fistula between the LCX and the right atrium, through the coronary sinus. A surgical approach that included proximal and distal ligation of the fistula with selective revascularization of the excluded obtuse marginal branch (OM) was chosen.