Using electrical shock for stopping rapid rhythm disorder. In most cases, this procedure is applied when the rhythm disorder deteriorates the patient's state and requires immediate stop.

In contradistinction to the term "Defibrillation", which designates treatment by electric shock in Ventricular Fibrillation, a lethal rhythm disorder, the term "Cardioversion" is reserved for electrical treatment of rapid rhythm disorders that are not Ventricular Fibrillation.