Electric shock is a treatment method that helps to quickly extinguish and stabilize cardiac arrhythmias. There are two methods of electric shock being used, including: cardioversion and defibrillation.

External cardioversion uses high-energy direct current (DC) energy delivered in a very short period of time to simultaneously depolarize most of the heart muscle cells to restore a normal heart rhythm.

Electric cardioversion is a method of using electric current to suppress rapid arrhythmias that are taking over the sinus rhythm, allowing the sinus rhythm to return to its role as the pacemaker. It should be noted that electric shock should not be understood as using electric current to "stimulate" the heart to beat.