Background: Right ventricular (RV) function assessment is crucial in CHD patients, especially in atrial septaldefect (ASD) and Tetralogy of Fallot (TOF) patients. Indeed, prognosis is very different between TOF patientswith pulmonary regurgitation and ASD patients, and only little is known about 3D deformation in RV overload. Purpose: The aim of our study was to assess RV remodeling differences between ASD, TOF patients andcontrols. Methods: We performed a prospective case­control study. We included 10 patients with an ASD (mean age53.3±21y) and 10 with TOF (mean age 34.9±18y) who were older than 16 years old, and compared them toa control group free from any cardiovascular disease (N=44, mean age 42.5±15y). 3D transthoracic RVechocardiographic sequences were acquired. Myocardial tracking was performed by a semi­automaticcommercial software. Output RV meshes included spatial correspondences. They were post­processed to alignthe data temporally and extract local deformation. Global and local statistics provided deformation patterns foreach subgroup of subjects. Results: Overall, ASD and TOF patients had similar but reduced RV ejection fraction (respectively 44.3±10and 44.5±12 %) and dilated right ventricles (mean RV EDV 158.3±100 and 115.4±46mL) using 3D analysis.Similar RV global area strain (GAS), global longitudinal strain (GLS) and global circumferential strain (GCS)were observed between the two groups. Compared to controls, ASD patients had lower GAS (­22.2±8 vs­29.4±5%; p=0.01), lower GCS (­12.9±4 vs ­17.1±4%; p=0.009) but similar GLS (p=0.07). TOF patientshad also lower GAS (­25.1±6%; p=0.03) but lower GLS (­10.0±3%; p=0.01) and similar GCS (­15.5±4%;p=0.4) in comparison with the control group. However, ASD patients had significantly lower CS in theinfundibular, inlet and membranous septum as compared with TOF patients (respectively p=0.02, p=0.05 andp=0.03). Conclusion: Volume overload in ASD patients seems to impact circumferential strain and preserve longitudinalstrain, whereas TOF patients tend to have lower longitudinal strain with preserved circumferential strain,probably because of the combination of RV pressure and volume overload. A larger cohort of patients couldhelp understand the insights of RV remodeling in congenital heart disease using 3D speckle­tracking imaging