Decreased defibrillator-induced dysfunction with biphasic rectangular waveforms.
Decreased defibrillator-induced dysfunction with biphasic rectangular waveforms.
复制标题
通过双相矩形波形减少除颤器引起的功能障碍。
DOI：
10.1152/ajpheart.1984.247.5.h792
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Jones,RE
中科院分区：
文献类型：
--
作者：
Jones,JL;Jones,RE
高强度电击用于心脏除颤可引起心律失常、S-T段改变，原位成功率低。培养的心肌细胞表现出类似的休克后心律失常，这些心律失常是由细胞膜的长时间去极化引起的。由于这种功能障碍可以通过双相RLC类型的波形得到改善，我们检查了矩形双相波形以最大限度地发挥这种有益作用，并阐明了功能障碍的诱发机制。用约80V/cm的单相5ms矩形波刺激培养的心肌细胞，产生持续4个S的震后收缩活动停止，用此对照波形交替给予具有相同起始部分的双相测试波形，然后是持续1~100ms的负“尾”和5~100%的初始正部分的幅度。来自31个双相波形的结果显示，休克后功能障碍发生了显著变化。欠冲高达10%且持续时间在5至100ms之间的波形可将停顿时间减少高达50%；欠冲大于20%的波形会导致较长的震后停顿时间。这些结果强化了心肌细胞膜的机电破坏是休克后功能障碍的基础的假设，并表明具有低幅度尾部的双相波形改善了这种功能障碍。
High-intensity electric shocks used for cardiac defibrillation produce arrhythmias, S-T segment changes, and a low percent success in situ. Cultured myocardial cells exhibit similar postshock arrhythmias that are caused by a prolonged depolarization of the cell membrane. Since this dysfunction is ameliorated by biphasic RLC-type waveforms, we examined rectangular biphasic waveforms to maximize this beneficial effect and clarify the dysfunction-inducing mechanism. Cultured myocardial cells were subjected to electric field stimulation with monophasic 5-ms rectangular waveforms of about 80 V/cm to produce a postshock arrest of contractile activity lasting 4 s. Shocks given with this control waveform were alternated with biphasic test waveforms having the same initial portion followed by negative "tails" 1-100 ms in duration and 5-100% of the initial positive portion in amplitude. Results from 31 biphasic waveforms demonstrated significant alterations in postshock dysfunction. Waveforms with up to 10% undershoot and ranging from 5 to 100 ms in duration decreased arrest time by up to 50%; waveforms with greater than 20% undershoot led to protracted postshock arrest times. These results strengthen the hypothesis that electromechanical breakdown of the myocardial cell membrane underlies postshock dysfunction and show that biphasic waveforms with low amplitude tails ameliorate this dysfunction.