Stepped defibrillation waveform is substantially more efficient than the 50/50% tilt biphasic.

Background: Even with biphasic waveforms, patients with high defibrillation thresholds (DFTs) still are seen; thus, improved defibrillation waveforms may be of clinical utility. The stepped waveform has three parts: the first portion is positive with two capacitors in parallel, the second is positive with the capacitors in series, and the last portion is negative, also with the capacitors in series.

Objectives: The purpose of this study was to assess the clinical utility of improved defibrillation waveforms.