right coronary artery to superior vena cava fistula following cabg: a very rare case report

Introduction: although most coronary artery fistulas to the venous system are congenital, we present a case who was conservatively treated and developed an acquired post-coronary artery bypass grafting (cabg) fistula between the right coronary artery (rca) and superior vena cava (svc) that due to with allow-flow shunt and few symptoms. case presentation: we report a 65-year-old man with a history of cabg 3 years ago presenting with chest pain. he developed a 3-vessel disease as well as a recent myocardial infarction with a reduced ejection fraction (25%). the case had chest discomfort since 2 months ago after discharge increasing by any physical activity. the consultant cardiologist decided to perform coronary angiography to assess the condition of the native coronary artery and coronary grafts. on coronary angiography, all of the grafts were patent; however, there was an abnormal communication between the proximal of native rca and svc that finally filled the right atrium. conclusion: clinically, although most coronary artery fistulas are silent and asymptomatic due to the limited size of the shunt, in some rare cases in which there is a large shunt and steal of coronary circulation, the symptoms and signs of ischemic heart disease appear that there are surgical and interventional options for closure of this abnormal communications.