Evaluation of the influence of the duration of the pause between the phases of depolarizing biphasic half-sinusoidal and truncated exponential defibrillation pulses on their energy efficiency

Data obtained from simulation the responses of cardiomyocytes in a state of simulated fibrillation to depolarizing biphasic half-sinusoidal and truncated exponential defibrillation pulses with pauses of different durations between pulse phases were used to plot graphs of the relationship between the proportion of the fibrillation cycle at which the defibrillation pulse provokes long-term extension of the refractory period of the cardiomyocyte (the defibrillation completeness index) and the relative energy of the defibrillation pulse. The simulation results showed that the energetically optimal duration of the pause between pulse phases was 1 msec for a biphasic half-sinusoidal defibrillation pulse, and for a biphasic truncated exponential pulse it is 2 msec, while its efficiency was close to that of a biphasic half-sinusoidal pulse. As the duration of the pause between phases increased beyond the optimal value, the energy efficiency of the defibrillation pulse decreased at high relative energy values.