Transcatheter pulmonary valve implantation (PVI) is an emerging therapy for right ventricular (RV) outflow dysfunction in congenital heart disease. We investigated, for the first time in children after surgery for congenital heart disease, the short-term effects of PVI on RV and left ventricular (LV) function using 2-dimensional speckle tracking echocardiography and tissue Doppler imaging. We hypothesized that the short-term RV and LV function would improve. Two-dimensional speckle tracking echocardiograms and pulsed tissue Doppler images were obtained before and 1 to 2 days after PVI (18-mm Melody valve). The catheter right heart hemodynamics were recorded. The strain and strain rate of the basal lateral left ventricle, lateral right ventricle, and interventricular septum were measured by 2-dimensional speckle tracking echo, and the pre- and postprocedure values were compared. Of the 16 eligible patients (age 16 +/- 2 years), the scans of 10 had correct image format and adequate quality. PVI was performed for volume (n = 4) or combined pressure-volume (n = 6) loading. After PVI, the RV to pulmonary artery pressure gradient (33 +/- 22 to 12 +/- 4 mm Hg, p = 0.02), pulmonary regurgitation, and RV end-diastolic volume (3.2 +/- 0.8 to 2.8 +/- 0.6 cm, p = 0.02) decreased, and the septal systolic velocities (3.5 +/- 1.1 to 4.7 +/- 1.1 cm/s, p = 0.04), strain (-7.6 +/- 9.3% to -15.6% +/- 6.7%, p = 0.01) and strain rate (-0.3 +/- 1.1 to -1.1 +/- 0.5 1/s, p = 0.04) and RV free wall strain increased (-17.4 +/- 8.6% to -23.4% +/- 6.2%, p = 0.03). The LV tissue velocities, strain, and strain rate were unchanged. In conclusion, PVI leads to RV unloading and acutely improves RV and septal function.