ABSTRACT
Unroofed coronary sinus syndrome (UCSS), also named coronary sinus septal defect, is a rare type of atrial septal defect with the incidence less than 1% of the total number of atrial septal defects. It is caused by incomplete formation of left atrial venous folds during embryonic development. Here we reported a patient with UCSS, who was treated in the Second Xiangya Hospital of Central South University. The patient was 50 years old and the main clinical manifestations were fatigue and shortness of breath after repeated exercise. Color Doppler echocardiography showed coronary sinus dilatation (17 mm×14 mm), indicating the possibility of permanent left superior vena cava. Pulmonary angiography showed that the left ventricle and coronary sinus were developed at the same time while the atrial septum was intact after the development of the left atrium, followed by the right atrium and right ventricle, indicating a partial anomalous pulmonary venous drainage (intracardiac type). Finally, the cardiac computed tomograhic angiography showed that 4 pulmonary veins and permanent left superior vena cava (PLSVC) went into the left atrium and the coronary sinus, respectively, while the coronary sinus septum was absent and the PLSVC was connected with the left atrium. The patient was later treated with the correction of non-parietal sinus syndrome in the Cardiovascular Surgery Department of our hospital.