Extensive early experience yielded no reliably validated instances of out-of-hospital arrest associated with tachyarrhythmia being resuscitated without successful defibrillatory shock. This together with the increasing availability of automated external defibrillators (AEDs), at increasingly attractive prices, led, in the past decade, to a strong emphasis on early defibrillation. This emphasis may have inadvertently resulted in a decreased emphasis on cardiopulmonary resuscitative techniques, particularly in light of publications decrying the uniformly poor quality of CPR performed by laymen, medical professionals, and even EMS personnel. However, recent research strongly suggests that assisted reperfusion prior to defibrillation may actually significantly improve survival rates. These reports, based on clinical studies, have received substantial confirmation from carefully controlled laboratory studies, particularly in pigs.