Cardioversion is a planned medical procedure done to restore a normal heart rhythm for people who have certain types of abnormal heartbeats (arrhythmias).Cardioversion is most often done by sending electric shocks to your heart through electrodes placed on your chest. Occasionally, your doctor may perform cardioversion using only medications to restore your heart's rhythm.Cardioversion is usually a scheduled procedure that's performed in a hospital, and you should be able to go home the same day as your procedure. For most people, cardioversion quickly restores a normal heart rhythm.