Agerskov M, et al. - This study was designed to elucidate the impact of automated external defibrillator (AED) feedback mechanisms on survival in out-of-hospital cardiac arrest (OHCA) victims. In addition, they further evaluated converting rates in patients with shockable rhythms according to AED shock waveforms and energy levels. There was no difference in survival after OHCA according to AED feedback mechanisms, nor any difference in converting rates according to AED waveform or energy levels.