Abstract Objective To investigate the effects of right ventricular apical pacing on electrical remodeling and ERK1/2 phosphorylation in beagle myocardium. Methods 12 male beagles, 3- 4 years old, underwent DDD pacemaker implanta-tion and were randomly divided into two groups (n=6). The pacemakers were turned on and programmed to ensure ventric-ular pacing 1 week after implantation in pacing group and turned off al the time in control group. The ECG and UCG were recorded before, 1 and 4 weeks after procedure with the pacemaker turned off. The beagles were sacrificed 4 weeks after procedure and phosphorylated ERK1 / 2 of right ventricular myocardium was determined by Western blotting. Results There was no statistical difference in the expression of ERK1 / 2, heart rate, QRS duration, BNP, ventricular myocardial pathology and parameters of UCG between the two groups. Tpeak- Tend interval and QT duration were prolonged and the expression of phosphorylated ERK1/2 increased in pacing group compared with control group(P<0.05) 4 weeks after pro-cedure. Conclusion Right ventricular apical pacing may induce myocardial repolarization prolongation and promote ERK1/2 phosphorylation of myocardium.
|
|
|
|
|