Background & Aims : Chronic right ventricular pacing (RVP) can lead to an increased risk of ventricular dyssynchrony (VD), heart failure and mortality. It is thought that ventricular dyssynchrony is affected by underlying disease, pacing mode, pacing site. We investigated the predictor of VD in patients implanted with permanent pacemaker (PPM). Methods: Total 197 patients (M:F=80:117, 67.7 짹 11.4 years) (Sick sinus syndrome (SSS): 71(36%), Atrioventricular block (AV block): 126(64%)) who were implanted with permanent pacemaker (AAI(R): 14(7.1%), VVI(R): 51(25.9%), VDD(R): 67(34.0%), DDD: 65(33.0%)) were enrolled this study. We analyzed baseline characteristics, 12-lead surface electrocardiogram, echocardiography and laboratory exam including hsCRP, proBNP. Ventricular dyssynchrony was evaluated by tissue Doppler imaging. The patients are divided into the two groups according to presence of VD. Results: At a mean follow-up of 6.98 years, VD was seen in 54.3% of patients with PPM. There was no statistical difference in baseline characteristics, surface 12 lead ECG, echocardiography, laboratory exam. In follow-up 2D echocardiography, right ventricular systolic pressure (RVSP) (33.48짹7.7 vs. 31.34짹4.86, p=0.026), E/E��� ratio (13.45짹8.23 vs. 11.23짹3.36, p=0.019) were higher in VD group. Also, logproBNP (2.41짹0.56 vs. 2.22짹0.43. p=0.015) were higher in VD group. In Cox proportional regression analysis, AV block (HR; 1.689, 95% CI = 1.039-2.744, p=0.034) were independent predictors of ventricular dyssynchrony. Conclusions: Diastolic dysfunction rather than systolic dysfunction, higher RVSP, higher serum pro-BNP was more associated with VD. AV block was the predictor of VD in patients treated with permanent pacemaker.