The conversion of an arrhythmia (abnormal heart rhythm), such as Atrial fibrillation, to a sinus (normal) rhythm, using an electrical defibrillator or by pharmacological means.

In synchronised electrical cardioversion, the patient is anaesthetised, defibrillator pads are placed on the patient, and a shock is delivered to the myocardium - synchronously with an ECG R-wave.

Energy levels
Atrial fibrillation120-150 joules200-360 joules
Atrial flutter70-120 joules100-150 joules
Ventricular tachycardia120-150 joules200-360 joules
Pharmalogical cardioversion
Give IV Amiodarone - 300mg over 1 hour.