Cardiopulmonary Resuscitation — Strengthening the Links in the Chain of Survival

The major determinants of survival after witnessed out-of-hospital cardiac arrest due to ventricular fibrillation include whether a bystander initiates cardiopulmonary resuscitation (CPR) and how quickly defibrillation is accomplished.The now-classic observations of Eisenberg et al. were that among patients with out-of-hospital cardiac arrest due to ventricular fibrillation, 43 percent survived to leave the hospital if CPR was initiated by a bystander within four minutes and if definitive therapy was delivered within eight minutes.1 Survival decreased to less than 7 percent if basic CPR was not initiated until 8 minutes, and no patient survived after 16 minutes of untreated ventricular fibrillation. . . .