The procedure is performed under a short general anaesthetic, and the patient must fast for 4 to 6 hours before the procedure. The shock is delivered through electrode pads placed on the chest and back. Up to 3 shocks may be given in an attempt to restore the heart's natural rhythm (sinus rhythm). No medication is usually given on the morning of the procedure, unless directed by the cardiologist.
Following cardioversion the patient is monitored for approximately one hour, and should not drive for 24 hours. A report will be sent to the referring doctor or GP, and the cardiologist performing the procedure will explain ongoing treatment and medication to the patient. If the patient has been on warfarin, it is important to continue this, usually for at least 3 weeks after the cardioversion.