To optimize the success of defibrillation, the clinician needs to minimize impedance, choose the proper energy level, apply the proper interface, select the appropriate paddle size, and deliver the shock at the earliest possible time. Other factors that may contribute to effective defibrillation include defibrillation during exhalation, maintenance of an effective airway, and correction of electrolyte abnormalities. Open chest defibrillation can be achieved at a lower dose of between 10 J and 20 J. Automated external defibrillators have increased survival of prehospital arrests. Cardioversion can generally be accomplished safely either as an elective or emergent procedure. Selection of the proper indications, protection of the airway, anticoagulation if necessary, correction of digitalis toxicity, and the utilization of adjuvant therapy ensure an optimal outcome.