Cardioversion is delivering an electrical shock to a person's heart to rapidly restore an abnormal heart rhythm back to normal.
There are two types of cardioversion -- external and internal.
An external cardioversion is often performed in an emergency situation. When a person's heart is beating abnormally and inadequately pumping blood to the body, an electrical shock is given with a defibrillator to revert the heart rate to a normal rhythm.
An internal cardioversion is delivered by a device similar to a pacemaker, called an implantable cardioverter defibrillator (ICD). This device is used for treating ventricular (lower heart chamber
) arrhythmias, such as ventricular tachyarrhythmias or fibrillation. The severity of these arrhythmias can cause sudden death because of the dangerously fast heart rate.
is a process in which an electronic device gives an electric shock
to the heart. This helps reestablish normal contraction rhythms in a heart having dangerous arrhythmia
or in cardiac arrest
. In recent years small portable defibrillators have become available. These are called automated external defibrillators or AEDs.