Electrical treatment of cardiac arrhythmias: defibrillation and cardioversion.

The passage of electrical current across the chest and heart to terminate ventricular fibrillation (defibrillation) or organized supraventricular or ventricular arrhythmias (cardioversion) is effective and safe. This paper reviews the physiology, techniques, and rationale for defibrillation and cardioversion. New developments and future directions are discussed. Rapid defibrillation is the most important factor in survival of out-of-hospital ventricular fibrillation.