Cardioversion is the delivery of an electric shock to the chest through electrodes or paddles. The shock is given to correct a dangerous heart rhythm.
Cardioversion can be done as an elective (scheduled) procedure or may be done urgently if an abnormal heartbeat is immediately life-threatening.
If the heart is not beating regularly, it may prevent the normal circulation of blood through the body. This may deprive various organs, including the brain and heart, of oxygen. Without oxygen, the organs cannot properly function and will eventually die.
In atrial fibrillation, the electrical signals from the atria are fast and irregular. The atria quiver, rather than contract. Some signals do not reach the ventricles and the ventricles continue pumping, usually irregularly and sometimes rapidly
Non-emergency cardioversion may be used to treat the following conditions:
Emergency cardioversion may be used to treat the following types of irregular heartbeats, which can lead to death if they are not immediately converted to a more normal rhythm:
Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:
For elective cardioversion:
For urgent cardioversion, there is no time for to prepare for the procedure.
You will have a short-acting deep sedation, so you will be unaware of the procedure happening.
Electrodes or paddles will be applied to the chest. An electric charge will be delivered through these electrodes or paddles to the chest and into the heart. This resynchronizes the electrical activity of the heart. It allows the heart’s normal pacemaker to resume normal function. The process may need to be repeated. The electric charge may be increased with each attempt.
You will be monitored closely in a recovery room until you are fully awake. You may be allowed to go home after the procedure. If medication needs to be started to keep your heart in rhythm, you may need to stay in the hospital.
The procedure itself is usually less than 30 minutes.
Sedation prevents pain during the procedure. If you have an urgent cardioversion, you may be partially aware during the procedure. You may feel a jolt that some people liken to a kick in the chest.
If you had nonemergency cardioversion, you may be sent home once you are in stable condition.
People who need emergency cardioversion may be admitted to the hospital. This may be done for further observation or because of the underlying illness that caused the event.
You may be put on blood thinners for a few weeks after the procedure. In this case, blood levels of these medications will need to be monitored via blood tests, usually weekly. Your doctor may also advise an anti-arrhythmic. This type of drug will help prevent the abnormal heartbeat from happening again.
It is important to monitor your recovery. Alert your doctor to any problems. If any of the following occur, call your doctor:
If you think you have an emergency, call for emergency medical services right away.
American Heart Association
Heart Rhythm Society
Canadian Heart Rhythm Society
Heart and Stroke Foundation of Canada
Cardioversion of atrial fibrillation. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T116136/Cardioversion-of-atrial-fibrillation. Updated February 22, 2017. Accessed November 28, 2017.
Direct-current (DC) cardioversion-defibrillation. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/direct-current-dc-cardioversion-defibrillation. Updated September 2017. Accessed November 28, 2017.
Overview of arrhythmias. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/cardiovascular-disorders/arrhythmias-and-conduction-disorders/overview-of-arrhythmias. Updated September 2017. Accessed November 28, 2017.
Last reviewed November 2018 by EBSCO Medical Review Board Michael J. Fucci, DO, FACC Last Updated: 12/20/2014