Background: Previous studies revealed that long-term right ventricular (RV) pacing is associated with left ventricular (LV) dyssynchrony. The purpose of this study was to evaluate the effect of long-term RV pacing on LV torsion. Methods: This study included 10 patients (mean age 65짹15 years) with complete atrioventricular block who treated with permanent pacemaker implantation. All patients had preserved LV systolic function after a minimum of 1 year of RV pacing. Apical and basal short-axis rotations were measured by 2-dimensional speckle-tracking echocardiography (2D-STE) and LV torsion was defined as the net difference of the apical and basal rotation. Ten age-matched healthy volunteers served as a control group and underwent 2D-STE. Results: The patients with RV pacing showed significantly decreased peak apical (7.99 짹 4.01째 vs. 15.66 짹 7.00째, p=0.008) and peak basal LV rotation (-2.51 짹 3.33째 vs. -7.88 짹 2.20째, p<0.001) compared with controls. LV torsion also decreased significantly in the patients with RV pacing (9.43 짹 2.86째 vs. 23.02 짹 8.40째, p=0.001). Conclusions: Long-term RV pacing significantly decreases peak apical-basal LV rotation and LV torsion.