Determination of Threshold Energy Level of Monopolar Defibrillation Pulses Using the Luo–Rudy Cardiomyocyte Model

The effect of defibrillation pulses of different waveforms on the Luo–Rudy cardiomyocyte model in the Cell Electrophysiology Simulation Environment (CESE) was comparatively tested. It was established that a half-sine pulse has the minimum threshold of cell excitation energy, while an exponential pulse exhibits the maximum threshold (22% increase in comparison with the half-sine pulse). The threshold energy of the trapezoidal pulse with sloped rising and falling (waveform of the first phase of bipolar pulse in imPulse AND-P automated external defibrillators at energy levels of 150 and 180 J) was only slightly (4%) higher than the threshold energy of the half-sine pulse. The threshold energy of truncated exponential pulses, which are widely used in modern defibrillators, exceeded the threshold energy of the half-sine pulse by 10-14% (depending on the decline value). These results obtained with the Luo–Rudy model differ significantly from the results obtained using the characteristic energy method with the Blair model.