Natale A, Sra J, Krum D, Dhala A, Deshpande S, Jazayeri M, Axtell K, Degroot P, VanHout W L, Akhtar M
Electrophysiology Laboratory, Milwaukee Heart Institute of Sinai Samaritan Medical Center, Wisconsin, USA.
Pacing Clin Electrophysiol. 1995 Jul;18(7):1354-61. doi: 10.1111/j.1540-8159.1995.tb02596.x.
With present implantable defibrillators, the ability to vary the defibrillation technique has been shown to increase the number of patients suitable for transvenous system. As newer waveforms become available, the need for a flexible device may change. In addition, although it has been shown that the option of biphasic waveform may increase the defibrillation efficacy, this may depend upon the shape of the biphasic waveform used. Thirty patients undergoing transvenous defibrillator implant were included in the study. In 20 patients (group I), defibrillation efficacy of simultaneous monophasic, sequential monophasic, and biphasic waveform with 50% tilt was determined randomly. Similarly, in ten patients (group II) testing of simultaneous monophasic shocks and biphasic waveforms with 65% and 80% tilt was performed in random order. The electrode system used consisted of two transvenous leads and a subcutaneous patch in all 30 patients. In group I, 50% tilt biphasic waveform consistently provided similar or better defibrillation efficacy compared to monophasic waveforms (biphasic 7.5 +/- 5.1 joules vs simultaneous 17 +/- 7.8 joules, P < 0.01; and vs sequential 17 +/- 8.4 joules, P < 0.01). In group II, 65% tilt biphasic pulse required less energy for defibrillation as compared with simultaneous monophasic shocks (9.6 +/- 4.5 joules vs 15.6 +/- 5.1 joules, P = 0.04). No significant difference was observed in terms of defibrillation threshold between 80% tilt biphasic shocks and simultaneous monophasic pulses (11.8 +/- 6 joules vs 15.6 +/- 5.1 joules, P = NS). Biphasic shocks with smaller tilt delivered using a triple lead system more uniformly improved defibrillation threshold over standard monophasic waveforms.
对于目前的植入式除颤器，已表明改变除颤技术的能力可增加适合经静脉系统的患者数量。随着更新的波形出现，对灵活设备的需求可能会改变。此外，尽管已表明双相波形选项可能会提高除颤效果，但这可能取决于所使用的双相波形的形状。该研究纳入了30例行经静脉除颤器植入的患者。在20例患者（I组）中，随机确定了单相同步、单相序贯和50%斜率双相波形的除颤效果。同样，在10例患者（II组）中，以随机顺序进行了单相同步电击和65%及80%斜率双相波形的测试。所有30例患者使用的电极系统均由两根经静脉导线和一个皮下贴片组成。在I组中，与单相波形相比，50%斜率双相波形始终提供相似或更好的除颤效果（双相7.5±5.1焦耳 vs 同步17±7.8焦耳，P<0.01；与序贯17±8.4焦耳相比，P<0.01）。在II组中，与单相同步电击相比，65%斜率双相脉冲除颤所需能量更少（9.6±4.5焦耳 vs 15.6±5.1焦耳，P = 0.04）。在80%斜率双相电击和单相同步脉冲之间，除颤阈值方面未观察到显著差异（11.8±6焦耳 vs 15.6±5.1焦耳）。使用三导联系统输送的较小斜率双相电击比标准单相波形更均匀地改善了除颤阈值。
