Trans-chest ventricular defibrillation of heavy subjects using trapezoidal current waveforms*

Summary Effectiveness of four truncated exponential waveform defibrillators for transchest ventricular defibrillation was evaluated in 27 human-sized animals. With all waveforms, effectiveness was virtually 100% for small subjects, but decreased as body weight increased. These data confirm the electrical dose concept for ventricular defibrillation and demonstrate that the truncated exponential waveform is effective only when adequate current is delivered through the subject's chest.