Greene H L, DiMarco J P, Kudenchuk P J, Scheinman M M, Tang A S, Reiter M J, Echt D S, Chapman P D, Jazayeri M R, Chapman F W
University of Washington, Seattle, USA.
Am J Cardiol. 1995 Jun 1;75(16):1135-9. doi: 10.1016/s0002-9149(99)80745-0.
All transthoracic defibrillators on the US market use nominally monophasic shock waveforms. However, biphasic waveforms have a lower defibrillation threshold than monophasic waveforms for transthoracic defibrillation of animals and for defibrillation of humans by implantable cardioverter defibrillators. The relative efficacies of Edmark monophasic and Gurvich biphasic transthoracic cardioversion waveforms (200 J into 50 omega) were compared for transthoracic cardioversion in 171 patients undergoing electrophysiologic study for evaluation of ventricular arrhythmias. Patients were randomized in a blinded fashion to receive either a monophasic or a biphasic waveform for the initial shock for conversion of induced ventricular arrhythmias (ventricular fibrillation [VF] = 53, monomorphic ventricular tachycardia [VT] = 80, polymorphic VT = 30, ventricular flutter = 8). Delivered energies for the Edmark and Gurvich waveforms were 215 +/- 11 and 171 +/- 11 J, respectively. There were no significant differences in patient characteristics, use of antiarrhythmic agents, arrhythmia cycle length, or duration of arrhythmia prior to shock for monophasic and biphasic waveform groups. The first shock for all arrhythmias was successful in 75 of 88 patients (85.2%) for the monophasic waveform compared with 81 of 83 patients (97.6%) for the biphasic waveform, p = 0.0054. The first shock for VF was successful in 22 of 28 patients (78.6%) for the monophasic waveform compared with 25 of 25 (100%) for the biphasic waveform, p = 0.0241. The Gurvich biphasic waveforms delivering a mean of 171 J were superior to Edmark monophasic waveforms delivering a mean of 215 J for transthoracic cardioversion of arrhythmias of short duration. This finding may have important implications for the development of future transthoracic defibrillators.
美国市场上所有的经胸除颤器名义上都使用单相电击波形。然而，对于动物经胸除颤以及植入式心脏复律除颤器对人类进行除颤而言，双相波形的除颤阈值低于单相波形。在171例接受电生理研究以评估室性心律失常的患者中，比较了Edmark单相和Gurvich双相经胸心脏复律波形（200焦耳，接入50欧姆）用于经胸心脏复律的相对疗效。患者被随机双盲分组，接受单相或双相波形作为首次电击，以转复诱发的室性心律失常（室颤[VF]=53例，单形性室性心动过速[VT]=80例，多形性VT=30例，心室扑动=8例）。Edmark波形和Gurvich波形的递送能量分别为215±11焦耳和171±11焦耳。单相和双相波形组在患者特征、抗心律失常药物使用、心律失常周期长度或电击前心律失常持续时间方面无显著差异。对于所有心律失常，单相波形组88例患者中的75例（85.2%）首次电击成功，而双相波形组83例患者中的81例（97.6%）首次电击成功，p=0.0054。对于室颤，单相波形组28例患者中的22例（78.6%）首次电击成功，而双相波形组25例患者中的25例（100%）首次电击成功，p=0.0241。对于短持续时间的心律失常经胸心脏复律，平均递送171焦耳的Gurvich双相波形优于平均递送215焦耳的Edmark单相波形。这一发现可能对未来经胸除颤器的研发具有重要意义。
