Postshock dysfunction induced by simulated one- and two capacitor defibrillator waveforms

Both symmetrical, two-capacitor (2-C), and asymmetrical, one-capacitor(l-C), biphasic waveforms enhance defibrillation efficacy compared to monophasic waveforms having the same total duration. However, the 1-C waveform is superior to the 2-C waveform. This study in isolated cells shows that the 1-C type waveform reduces postshock dysfunction while the 2-C waveform does not. Reduction of postshock dysfunction, which can lead to conduction block and refibrillation, may be one mechanism for greater 1-C defibrillation efficacy.