Objective: To investigate the effects of carvedilol （CVD） on transmural dispersion of repolarization（TDR） and arrhythmia in pressure over-load rabbits. Methods: Left ventricular hypertrophied（LVH） rabbit models were established by pressure over-load; All animal models were assigned into CVD group or LVH group randomly. The action potentials of endocardium

epicardium and transmural ECG of arterially perfused left ventricular preparations were recorded concurrently. Action potential duration （APD）

TDR

ventricular arrhythmia and ultrasonic parameters

ratio of LVM to body weight （LVMI） were compared correspondingly. The stable plasma concentration of carvedilol in CVD group was detected by HPLC. APD

TDR and arrhythmia of LVH models were compared just preor post-perfusion with stable concentration of CVD. Results: In Contrast with values in LVH group

LVEFof CVD group were significantly elevated while the LVMI was remarkably reduced

TDRs were significantly shortened

and ratio of ventricular arrhythmia was lowered remarkably. No significant difference of APD

TDR and ratio of arrhythmia was found pre- or post-perfusion at stable plasma concentration of CVD. Conclusion: CVD can ameliorate the structure and function of pressure over-load ventricles; CVD contributes to the improvement of ventricular arrhythmia associated with its long-term effect on APD

TDR shortening

whereas has nothing to do with its transient function on ionic channel blockade.