Exner D, Yee R, Jones D L, Klein G J, Mehra R
Department of Medicine, University of Western Ontario, London, Canada.
J Am Coll Cardiol. 1994 Feb;23(2):317-22. doi: 10.1016/0735-1097(94)90413-8.
We hypothesized that combining biphasic waveform and sequential pulse defibrillation techniques would lower the defibrillation threshold of a nonthoracotomy lead system in humans below that obtained with biphasic or sequential pulse defibrillation alone.
Previous studies have shown that sequential pulse monophasic shocks and biphasic waveform shocks are more effective than single monophasic shocks for ventricular defibrillation.
Thirteen patients aged 48 to 71 years undergoing nonthoracotomy defibrillation lead testing participated in the study. Transvenous electrodes were positioned in the right ventricular apex, superior vena cava and coronary sinus. A cutaneous patch electrode was placed on the left chest wall. All electrodes were connected to an external defibrillator. In random order, defibrillation threshold measurements were made for biphasic defibrillation alone, sequential defibrillation alone and combined biphasic plus sequential defibrillation.
The mean defibrillation threshold-delivered energy was 18.0 +/- 11.9 J for biphasic defibrillation and 16.3 +/- 9.0 J for sequential defibrillation. Biphasic plus sequential defibrillation significantly reduced the threshold energy to 10.2 +/- 5.3 J (p < 0.001). Threshold peak voltage and current values showed corresponding reductions. The combined waveform resulted in a greater reduction in defibrillation threshold in patients with threshold energies > 18 J versus those with threshold values < or = 18 J for sequential (p = 0.001) or biphasic (p < 0.01) waveform alone. The nonthoracotomy lead implantation rate was improved from 62% with each of the single techniques (biphasic waveform or sequential pulse defibrillation) to 85% with the combined waveform.
Adding biphasic waveform to sequential pulse defibrillation significantly reduced the defibrillation threshold compared with either technique alone, and nonthoracotomy lead system implantation can be enhanced by this combined technique.
我们推测，将双相波形和序贯脉冲除颤技术相结合，可使非开胸导联系统在人体中的除颤阈值低于单独使用双相或序贯脉冲除颤时获得的阈值。
先前的研究表明，序贯脉冲单相电击和双相波形电击在心室除颤方面比单次单相电击更有效。
13名年龄在48至71岁之间接受非开胸除颤导联测试的患者参与了该研究。经静脉电极置于右心室心尖、上腔静脉和冠状窦。在左胸壁放置一块皮肤贴片电极。所有电极均连接到一台体外除颤器。以随机顺序分别测量单独使用双相除颤、单独使用序贯除颤以及双相加序贯联合除颤的除颤阈值。
双相除颤的平均除颤阈值释放能量为18.0±11.9焦耳，序贯除颤为16.3±9.0焦耳。双相加序贯除颤显著降低阈值能量至10.2±5.3焦耳（p<0.001）。阈值峰值电压和电流值也相应降低。与单独使用序贯（p=0.001）或双相（p<0.01）波形相比，联合波形使阈值能量>18焦耳的患者除颤阈值降低幅度更大。非开胸导联植入率从单独使用每种技术（双相波形或序贯脉冲除颤）时的62%提高到联合波形时的85%。
与单独使用任何一种技术相比，在序贯脉冲除颤中添加双相波形可显著降低除颤阈值，并且这种联合技术可提高非开胸导联系统的植入成功率。
