Objective To investigate the value of three-dimensional speckle tracking imaging (3D-STI) in quantitative evaluation of left ventricular global strain in patients with atrial septal defect (ASD) before and after transcatheter closure.Methods Totally 35 patients with secondary ASD who received successful transcatheter occlusion were selected.Routine echocardiography and 3D-STI examination were performed before the operation,2 days,1 month,3 months and 6 months after the operation.Routine echocardiography was used to obtain the parameters of left ventricular end diastolic diameter (LVEDD),left ventricular end systolic diameter (LVEDS),left ventricular end diastolic volume (LVEDV),left ventricular end systolic volume (LVESV),stroke volume (SV) and other parameters.The left ventricular global peak longitudinal strain (GPLS),left ventricular global peak circumferential strain (GPCS),left ventricular global peak radial strain (GPRS) and left ventricular global peak area strain (GPAS) were examined with 3D-STI.The preoperative and postoperative parameters at each time point were analyzed statistically.Results Routine echocardiography showed that LVEDD,LVEDS,LVEDV,LVESV and SV increased significantly after operation,but no significant difference was found to compare each other 2 days,1 month,3 months and 6 months after operation (all P＞0.05).3D-STI examination showed that left ventricular GPLS,GPCS,GPRS and GPAS increased after operation,and the most increase was noticed at the second day after transcatheter occlusion.GPLS,GPCS and GPAS 6 months after operation were larger than those 3 months after operation (all P＞0.05).Conclusion 3D-STI technique can evaluate the left ventricular global strain in patients with ASD before and after occlusion.Compared with conventional echocardiography,3D-STI technique can objectively and effectively evaluate the changes of left ventricular systolic function.