Recent reports consistently point to a substantial decline in the incidence of ventricular fibrillation (VF) as the initial rhythm observed by Emergency Medical Service (EMS) responders and a complementary increase in pulseless electrical activity (PEA) and asystole. Historically, efforts at improving survival have focused primarily on patients found in VF. Consequently, the approach for other patients has included frequent pauses in cardiopulmonary resuscitation (CPR) to check for VF followed by shock when VF is observed. However, the "yield" of survivors comes largely from the non-shocked patients. Therefore, it is critical that we start evaluating treatments specifically for the PEA and asystole groups.