Improved defibrillator waveform safety factor with biphasic waveforms.
Improved defibrillator waveform safety factor with biphasic waveforms.
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使用双相波形提高了除颤器波形安全系数。
DOI：
10.1152/ajpheart.1983.245.1.h60
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发表时间：
1983
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
在用双相、截断和整流欠阻尼 RLC（电阻-电感-电容）型波形进行电场刺激后，研究了“成年型”培养的鸡胚心肌细胞的兴奋阈值和心律失常，以检验双相波形的负相改善由初始正部分引起的膜功能障碍的假设。光电管力学图和细胞内微电极监测期外收缩和去极化引起的心律失常。整流或截断双相波形不会改变激励阈值。然而，当双相波形被截断或校正时，产生特定电击后心律失常或特定严重程度的电击后长时间去极化的电击强度存在显着差异。截断版本产生特定功能障碍的电压梯度比双相版本低 12-14%；整流版本比双相版本低 17-27%（尽管两者包含相同的能量）。针对每个波形确定安全系数，即产生特定功能障碍的冲击强度与产生兴奋的冲击强度之间的比率。双相波形比截断或整流波形具有更大的安全系数。由于在培养的心肌细胞中测量的安全系数与原位除颤有效性密切相关 (14)，因此双相波形显着较高的安全系数表明精心设计的双相波形可能会提高心脏除颤程序的有效性和安全性。
Excitation thresholds and arrhythmias were studied in "adult-type" cultured chick embryo myocardial cells after electric field stimulation with biphasic, truncated, and rectified underdamped RLC (resistance-inductance-capacitance) type waveforms, to test the hypothesis that the negative phase of biphasic waveforms ameliorates membrane dysfunction induced by the initial positive portion. Photocell mechanograms and intracellular microelectrodes monitored extrasystoles and depolarization-induced arrhythmias. Rectifying or truncating biphasic waveforms did not alter the excitation threshold. However, shock intensities producing specific postshock arrhythmias or a specific severity of postshock prolonged depolarization differed significantly when biphasic waveforms were truncated or rectified. The voltage gradient producing a specific dysfunction was 12-14% lower for the truncated version than for the biphasic; that for the rectified version was 17-27% lower than for the biphasic version (although both contained the same energy). Safety factor, the ratio between shock intensity producing specific dysfunction and that producing excitation, was determined for each waveform. Biphasic waveforms had larger safety factors than truncated or rectified waveforms. Since safety factor, as measured in cultured myocardial cells, closely corresponds with in situ defibrillating effectiveness (14), the significantly higher safety factors of biphasic waveforms suggest that carefully shaped biphasic waveforms might improve the efficacy and safety of cardiac defibrillation procedures.