迷走神经的随机扰动对心肌电生理特性的影响

EFFECT OF STOCHASTIC VAGALMODULATION ON THE ELECTROPHYSIOLOGICAL CHARACTERISTICS OF CARDIAC

本文以Zhang等人构建的完整兔子心脏模型为研究对象,通过计算机仿真模拟,研究了迷走神经的随机波动对心肌细胞体系动力学行为的影响.模拟发现,一方面,迷走神经对心脏起搏的随机调节可以产生一种"混沌"的窦性心律,如刺激迷走神经或施加乙酰胆碱(Acetycholine:ACh)到心脏,可诱发心房颤动、房性心动过速和窦性心律不齐等心律失常病态现象.另一方面,ACh对心肌细胞的变异性影响包括对ACh激活的IK,ACh,L型钙电流ICa,L与INa动力学行为的调控上.上述结果表明外部环境中作用于迷走神经的随机扰动刺激对心肌细胞电生理特性有重要影响和调控作用,这将有助于从理论上揭示人类心脏心律失常现象的内在规律及形成机制,为进一步进行心律异常的实验研究与临床诊断和预防提供一定的科学依据.

In this paper, a complete heart model of rabbit proposed by Zhang et al. is used as a research sub- ject, and the effect of random fluctuation of vagus nerve on the dynamic behavior of cardiac cell system was studied by computer simulation. The results showed that, on the one hand that, the stochastic regulation of the vagus nerve on cardiac pacing could produce a ＂chaotic＂ sinus rhythm, for example, some pathological phenomena, such as, atrial fibrillation, atrial tachycardia as well as sinus arrhythmia could be induced by stimulating vagal or applying ACh to the cardiac. On the other hand, the effect of ACh on the variability of cardiac cells includes the regulation of some currents, such as, IK,ach, Ic~,L and INa. Our results suggest that the random disturbance in the external en- vironment may play an important role on the electrophysiological properties of cardiac. It will help us to reveal the internal rules and mechanisms about the phenomenon of the human heart arrhythmia, and it will also provide scien- tific clues for further research and both the clinical diagnosis and prevention of arrhythmia.