Background: Quantitative assessment of the right ventricular (RV) function in atrial septal defect (ASD) patients before and after closure remains difficult. The aim of this study was to assess the regional RV function in ASD patients, to evaluate the extent and time course of RV remodeling following ASD closure, and to investigate whether any regional difference exists in RV remodeling. Methods: Twenty patients with ASD and 20 age-matched controls were included. All underwent standard echocardiography and two-dimensional strain (S) and strain rate (SR) imaging by speckle tracking before, and 24hours and 1month after the defect closure. Results: Right ventricular S was higher in ASD patients except apical lateral segment S, which was lower when compared with controls. There was no difference in RV SR between ASD patients and controls. RV septal S and SR, and lateral SR decreased in 24hours after the procedure and remained the same at 1month. RV lateral basal and mid S decreased and apical S increased in 24hours after the closure. All 3 segments showed some more increase at 1month. RV apical S showed strong correlations with systolic pulmonary artery pressure and global RV systolic function indices. Conclusions: Chronic volume overload in ASD patients causes alterations in RV deformation. Percutaneous closure results in rapid remodeling and normalization of RV deformation. The major geometrical and deformational changes are completed in 24hours. Lateral wall S seems to reflect the RV deformational changes due to volume loading and unloading better than SR in ASD patients.