Patient population
This was a retrospective study, patients who underwent closures of secundum ASD with the Amplatzer septal occluder (ASO, AGA Medical Corporation, Golden Valley, N, USA) successfully from March 2016 to February 2020 in Renmin Hospital of Wuhan University were enrolled in this study. The transesophageal echocardiography was performed by experienced investigators. Patients with arrhythmias, poor quality of transesophageal echocardiographic images or lack of complete clinical data as the size of ASO were excluded. A total of 40 patients had both 2D-TEE images and 3D-TEE images of high quality in our hospital database were finally considered for this study, of which 4 cases with double-hole, secundum ASD and 36 cases with isolated secundum ASD. All patients have complete clinical medical records. Baseline characteristics of the study population are reported in Table1.The study protocols were approved by the ethics committee at Renmin Hospital of Wuhan University. All patients or legal guardians gave their informed consent to study inclusion.