Teaching Case

A 57-year-old male patient with symptoms of intermittent chest pain was admitted to our hospital. Physical examination revealed hypertension. Transpoesophageal echocardiography and electrocardiography was nonspecific.

ECG gated multidetector computed tomography (MD-CT) angiography was performed for evaluation to coronary arteries. MD-CT showed high grade stenosis in right coronary artery (RCA). Sinoatrial artery which was a branch of right coronary artery (RCA), fistulated to the left atrium after passed through the junction of superior vena cava and right atrium. The fistula did not have high volume.

There are not any cases in literature about the fistula between the sinoatrial artery and the left atrium. Coronary artery fistula is the communication between a coronary artery and a cardiac chamber, great artery or vena cava [1]. The incidence of coronary artery fistulas is 0,3–0,8% in angiographic series and arises from the right coronary artery in 55% of cases. Fistulas drain into the right ventricle in 41%, right atrium in 26%, pulmonary artery in 17%, left ventricle in 3%, and superior vena cava in 1% of cases [2]. Coronary artery fistulas are usually asymptomatic in adults. Symptoms mainly depend on the severity of shunt. The major clinical risk in adults is myocardial infarction due to decreased coronary blood flow distal to the fistula even if there is no evidence of coronary atherosclerosis [3].