Optimal small-capacitor biphasic waveform for external defibrillation - Influence of phase-1 tilt and phase-2 voltage

Article; Proceedings Paper

关键词: TRANSTHORACIC DEFIBRILLATION;    MINIMAL MODEL;    EFFICACY;    FORMS;    MECHANISMS;    ELECTRODE;    SHOCKS;    PULSES;    SINE;   

DOI  :  10.1161/01.CIR.98.22.2487

来源: SCIE

【 摘 要 】

Background-Biphasic waveforms have been reported to be more efficacious than monophasic waveforms for external defibrillation. This study examined the optimal phase-1 tilts and phase-2 leading-edge voltages with small capacitors (60 and 20 mu F) for external defibrillation. We also assessed the ability of the charge-burping model to predict the optimal waveforms. Methods and Results-Two groups of studies were performed. In group 1,9 biphasic waveforms from a combination of 3 phase-1 tilt values (30%, 50%, and 70%) and 3 phase-2 leading-edge voltage values (0.5, 1.0, and 1.5 times the phase-1 leading-edge voltage, V-1) were tested. Phase-2 pulse width was held constant at 3 ms in all waveforms. Two separate 60-mu F capacitors were used in each phase. The energy value that would produce a 50% likelihood of successful defibrillation (E-50) decreased with increasing phase-1 tilt and increased with increasing phase-2 leading-edge voltage except for the 30% phase-1 tilt waveforms. In group 2, 9 waveforms were identical to the waveforms in group 1, except for a 20-mu F capacitor for phase 2. E-50 decreased with increasing phase-1 tilt. Phase-2 leading-edge voltage of 1.0 to 1.5 V-1 appeared to minimize E-50 for phase-1 tilt of 50% and 70% but worsened E-50 for phase-1 tilt of 30%. There was a significant correlation between E-50 and residual membrane voltage at the end of phase 2, as calculated by the charge-burping model in both groups (group 1, R-2=0.47, P<0.001; group 2, R-2=0.42, P<0.001). Conclusions-The waveforms with 70% phase-1 tilt were more efficacious than those with 30% and 50%. The relationship of phase-2 leading-edge voltage to defibrillation efficacy depended on phase-2 capacitance. The charge-burping model predicted the optimal external biphasic waveform.

【 授权许可】

Free