快速右心室起搏对犬心肌动作电位的影响

Influence of Rapid Right Ventricular Pacing on Cardiac Action Potential in Dogs

目的犬快速右心室起搏3周构建心衰模型,探讨心衰模型中单个心肌细胞动作电位变化。方法采用对照研究的方法将10条杂种犬分成两组即起搏犬组和对照组。比较两组活体单个心肌细胞动作电位。结果起搏犬起搏3周均出现心衰且心肌细胞动作电位复极90%时程及复极50%时程均较对照组明显延长。结论在快速右心室起搏成功构建心衰模型中心肌细胞发生明显电重构。

Objective To establish an useful animal model of low-output heart failure by rapid right ventricular pacing in dogs and to evaluate the effects of rapid right ventricular pacing at 230 ± 10 beats per minute for 3 weeks on myocardial action potential. Methods The following groups of Mongrel dogs （20 - 25 kg） were studied： sham operation group （n = 5） and pacing group （n = 5）. The pacing group was subjected to rapid right ventricular pacing for 3 weeks （230 ± 10 beats per minute）. Investigators were blinded to treatment assignment until all analyses were completed to observe action potential of the ventricle. Results Compared with 5 control dogs, dogs paced for 3 weeks （n = 5 ） exhibited reduced cardiac output and significantly prolonged action potential duration （APD）. Conclusion Those data indicate that rapid ventricular pacing in the dogs may generate an useful experimental model of low-output heart failure characterized by biventricular electricity remodeling.