Objective To study the changes of left ventricular structure and function after transcatheter closure of atrial septal defect(ASD)by strain rate(SR)imaging.Methods Twenty-eight patients with secundum type ASD were undergone transcatheter closure.Left and right ventricular end-diastolic diameter(LVED and RVED),left ventricular ejection fraction(LVEF),the Doppler transmitral filling velocities(E values and A values)and tricuspid regurgitation pressure were measured respectively at pre-operation,3 days,1 month and 3 months of post-operation.According to tricuspid regurgitation pressure,systolic pulmonary artery pressure(SPAP)was estimated.SR curves in all segments of left ventricular walls were acquired for all patients.The SR values including the peak of systolic SR,early-diastolic SR,late-diastolic SR were measured respectively.ResultsAfter operation,LVED,LVEF,E values and A values increased significantly while RVED and SPAP decreased.Almost all left ventricular walls' SR increased at post-operation except that SR of interventricular septeum(IVS)and left ventricular post wall(LVPW)decreased at 3 days,1 month of post-operation.Conclusions LV systolic and diastolic function are improved after operation,but SR characteristic changes of IVS and LVPW is the one of the most unique characters.