Cardioversion is a method to bring an abnormal heart rhythm back to normal.
Cardioversion can be done using an electric shock or with drugs.
Electric cardioversion is done with a device that gives off an electrical shock to the heart to change the rhythm back to normal. The device is called a defibrillator.
The shock can be delivered from a device outside the body called an external defibrillator. These are found in emergency rooms, ambulances, or some public places such as airports.
An external defibrillator is used to treat abnormal heart rhythms (arrhythmia) that cause collapse and cardiac arrest. Examples are ventricular tachycardia and ventricular fibrillation.
These same devices may also be used to treat less dangerous abnormal rhythms, problems such as atrial fibrillation. The defibrillator will be used when the abnormal heart rhythm cannot be controlled with medicine.
An implantable cardioverter-defibrillator (ICD) is a device that is placed inside your body. It is most often used in people who are at risk for sudden death because their heart function is so poor, or they have had dangerous heart rhythms before.
CARDIOVERSION USING DRUGS
Cardioversion can be done using drugs that are taken by mouth or given through an intravenous line (IV). It can take from several minutes to days for this treatment to work. This treatment is often done while in a hospital where your heart rhythm will be monitored.
Cardioversion using drugs can be done outside the hospital. This treatment is most often used for people with atrial fibrillation that comes and goes. However, you will need to be closely followed-up by a cardiologist.
You may be given blood thinning medicines to prevent blood clots from forming and leaving the heart (which can cause a stroke).
Complications of cardioversion are uncommon, but may include:
People who perform external cardioversion may be shocked if the procedure is not done correctly. This can cause heart rhythm problems, pain, and even death.
Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 10/04/2018.