Comparison of three biphasic defibrillation waveforms: Gurvich waveform is more efficient

The biphasic waveform has greater defibrillation efficacy than the monophasic waveform. Yet, the optimal type of biphasic defibrillation waveform is still unknown. Our objective was to compare the defibrillation efficacy of three morphologically different biphasic waveforms (named as truncated exponential waveform, modified Zoll waveform, and Gurvich waveform) in an isolated Langendorff perfused rabbit heart. Optical potential mapping techniques were used. The result showed that the Gurvich waveform has the lowest defibrillation threshold (DFT). A multiple comparison test showed that there is a significant difference of DFTs between the modified Zoll waveform and Gurvich waveform (mean/spl plusmn/SE: 0.31/spl plusmn/0.03 J and 0.25/spl plusmn/0.02 J, p<0.02). We also examined the change of membrane potential caused by shocks. The result showed an homogeneous response for different waveforms.