Electrical cardioversion is a procedure that uses an electric current to stop the heart momentarily. This helps the heart have a normal rhythm when it resumes beating.

Usually a person is given a sedative before the procedure. Then patches are placed on the person’s chest. The patches send an electrical current to the heart. An external defibrillator, which has paddles, might be used in some situations. Doctors are prepared to help maintain a person’s circulation during the procedure with medicines and other methods.

Cardioversion may be used to help the heart return to a normal rhythm after medicines have failed to do so. The procedure also may be done in emergency situations. For example, it may be done to correct a fast heart rhythm that is causing low blood pressure, chest pain, or heart failure.