In the Emergency Department, electrical cardioversion is often preferred to chemical cardioversion for many reasons. Electrical cardioversion is simple and quick to perform. It is effective—in most cases almost immediately. It may be more successful tha

Defibrillation. At the end of the 18th century two physiologists, Prévost and Batelli, performed shock experiments on the hearts of dogs. They applied electrical shocks and discovered that small shocks put the dogs' hearts into VF and this was succes

Cardioversion and defibrillation efficacy increases with use of biphasic shocks, in which the current polarity is reversed part way through the shock waveform. For defibrillation of ventricular fibrillation or pulseless ventricular tachycardia the energy