Cardioversion You are here:HomeOur ServicesClinical servicesCardiology ServicesDiagnostic servicesCardioversion Cardioversion refers to the process of restoring the normal heart rhythm from an abnormal rhythm. Most elective cardioversions are performed to treat atrial fibrillation, a heart rhythm disturbance originating in the upper chambers (atria) of the heart. It involves applying an electric shock to the heart whilst you are under anaesthetic