体表电刺激对新西兰大白兔心电活动的影响

Effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits

目的研究体表电刺激对新西兰大白兔心电活动的影响,寻找临床电刺激疗法的安全阈值,为体外起搏器的设计提供理论依据。方法将新西兰大白兔随机分为17组,每组6只。设脉冲电刺激实验组16组,电刺激部位均在大白兔中上腹区,根据电压不同分为5、10、15、20、25、30、35、40、45、50、55、60、65、70、75、80V组。用BL-420F型生物机能实验系统提供刺激电源并采集心电图,系统输出脉冲电刺激频率均为270次/min,刺激波为方波。设一组部位对照组,刺激电压35V,刺激正极位于胸部心前区,刺激负极位于背部心脏对应部位皮肤表面,余同实验组。结果电压≤35V实验组大白兔未出现刺激心律,部位对照组为全刺激心律。电压≤30V实验组大白兔未出现心律失常。电压≥45V实验组大白兔刺激结束后心率减慢。电压≤35V实验组大白兔无行为异常或仅有轻度行为异常。电压≤40V实验组大白兔电刺激局部组织肉眼观察无损伤。结论电压≤35V脉冲电刺激中上腹区不影响大白兔心电活动。35V脉冲电刺激兔心脏前后极可导致心脏全起搏心律,但不会影响新西兰大白兔自身心电活动,且不会造成局部组织损伤。

Objective To study the effect of transcutaneous electric stimulation on the cardiac electrical activity in New Zealand white rabbits, in order to search a safety threshold for clinical electrical stimulation therapy, as to provide the theoretical basis for the design of in vitro pacemaker. Methods New Zealand white rabbits were randomly assigned into 17 groups （6 each）. Rabbits in 16 experimental groups were given 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 and 80V electrical stimulation, respectively, with the stimulating site designated at epigastric region. BL-420F biological function experimental system was employed to supply the power and acquire the ECG, with the output pulse electrical stimulation frequency set at 270 times/minute, and the stimulating wave as square wave. A control group was set, in which the stimulating voltage was set to 35V, the stimulant anode was located in the anterior chest area, and the cathode was on the skin surface of back corresponding to the site of the heart, and the rest was the same as in experimental groups. Results No stimulation rhythm was observed in rabbits of those experimental groups with voltage ≤ 35V, but all stimulation rhythm was observed in rabbits of control group. No arrhythmia occurred in rabbits of those experimental groups with voltage ≤ 30V, while the heart rate was slowed down after stimulation in rabbits of the experimental groups with voltage ≥ 45V stimulation. In rabbits receiving stimulation with voltage ≤ 35V there was no dystropy or light dystropy, but with no visible injury to the local tissues. No visible injury was observed in the rabbits undergoing stimulation with voltage ≤40V. Conclusion Pulse electric stimulation with voltage ≤ 35V in the epigastric region would not affect the cardiac electrical activity in rabbits, while stimulation with 35V will lead to all pacing rhythm of the heart without affecting the cardiac electrical activity in rabbits, and it does not produce local tissue injury.