The patient was diagnosed by echocardiography in a foreign hospital due to "chest pain": "right coronary artery-left atrial fistula", and a series of imaging examinations in our hospital confirmed the diagnosis: right coronary artery-superior vena cava fistula, with tumor-like expansion of the superior vena cava . Percutaneous coronary angiography confirmed the fistula closure, and postoperative transthoracic echocardiography showed no residual shunt. The out-of-hospital examiners mistakenly regarded the superior vena cava aneurysm as the left atrium, and did not scan the superior vena cava aneurysmal dilatation. For coronary fistula, it is necessary to patiently track the abnormal blood flow path, carefully identify the typical anatomical structure, and perform multi-section scanning to reduce missed diagnosis and misdiagnosis.