Even with the widespread practice of basic and advanced life support, the vast majority of patients in cardiac arrest never survive to hospital discharge. Each year over one million Europeans and Americans die from sudden cardiac arrest. The waste of human potential is enormous. Contrary to popular opinion, many of the victims die in their prime. Survival rates for out-of-hospital cardiac arrest vary geographically from 1% to 18%, while the in-hospital cardiac arrest survival rates vary from 5% to 25%. Differences in outcomes between geographic regions are due to many factors, but the intrinsic mechanical inefficiencies of standard cardiopulmonary resuscitation (sCPR) limit the potential of even the most highly skilled rescuers. Since the description of sCPR by Kouwenhoven and colleagues in 1960, several new cardiopulmonary resuscitation (CPR) techniques and a number of different CPR adjunctive devices have been described. These new approaches were developed based on insights into the mechanisms of blood flow during CPR.