Electric shock. That is used to revert your heart to a regular rhythm.
Jolt of electricity. Cardioversion varies from life threatening emergency conditions in cases of ventricular fibrillation - called "defibrillation"-cases of cardiac arrest - to semi elective situations for conditions such as atrial fibrillation. In all such cases, the goal is to jolt your heart with an electric shock to re-establish a normal "sinus" rhythm.
Converts rhythm. Converts rhythm from atrial fibrillation to regular sinus rhythm.