Person undergoing cardioversion

Cardioversion is a medical procedure that restores a normal heart rhythm in people with certain types of abnormal heartbeats (arrhythmias).

Cardioversion is usually done by sending electric shocks to your heart through electrodes placed on your chest. It's also possible to do cardioversion with medications.

Cardioversion is usually a scheduled procedure that's performed in a hospital. You should be able to go home the same day as your procedure. For most people, cardioversion quickly restores a normal heart rhythm.

Why it's done

Cardioversion can correct a heartbeat that's too fast (tachycardia) or irregular (fibrillation). Cardioversion is usually done to treat people who have atrial fibrillation or atrial flutter. These conditions occur when the electrical signals that normally make your heart beat at a regular rate don't travel properly through the upper chambers of your heart.

Cardioversion is usually scheduled in advance but is sometimes done in emergency situations.

Cardioversion is usually done with electric shocks, which are given through electrodes attached to your chest while you're sedated. Electric cardioversion allows your doctor to instantly see if the procedure has restored a normal heartbeat.

Electric cardioversion takes less time than cardioversion done solely with medications. If your doctor recommends cardioversion with medications to restore your heart's rhythm, you won't receive electric shocks to your heart.

Cardioversion is different from defibrillation, an emergency procedure that's performed when your heart stops or quivers uselessly. Defibrillation delivers more powerful shocks to the heart to correct its rhythm.


Complications of electric cardioversion are uncommon. Your doctor can take steps to reduce your risk. Major risks of cardioversion include:

  • Dislodged blood clots. Some people who have irregular heartbeats have blood clots in their hearts. Electric cardioversion can cause these blood clots to move to other parts of your body. This can cause life-threatening complications, such as a stroke or a blood clot traveling to your lungs.

    If necessary, your doctor may prescribe blood-thinning medications before the procedure or will check for blood clots in your heart before cardioversion.

  • Abnormal heart rhythm. In rare cases, some people who have cardioversion develop other heart rhythm problems during or after the procedure. This is a rare complication. If it happens, it usually shows up only minutes after your procedure. Your doctor can give you medications or additional shocks to correct the problem.
  • Skin burns. Rarely, some people have minor burns on their skin where the electrodes were placed.

Cardioversion can be done during pregnancy, but it's recommended that the baby's heartbeat be monitored during the procedure.

How you prepare

Cardioversion procedures are usually scheduled in advance. However, if your symptoms are severe, you may need to have cardioversion in an emergency setting.

You typically can't eat or drink anything for about eight hours before your procedure. Your doctor will tell you whether to take any of your regular medications before your procedure. If you do take medications before your procedure, sip only enough water to swallow your pills.

Before cardioversion, you may have a procedure called a transesophageal echocardiogram to check for blood clots in your heart. Blood clots can break free by cardioversion, causing life-threatening complications. Your doctor will decide whether you need a transesophageal echocardiogram before cardioversion.

If your doctor finds blood clots, your cardioversion procedure will be delayed for three to four weeks. During that time, you'll take blood-thinning medications to reduce your risk of complications.

What you can expect

During the procedure

You'll be given medications through an IV to make you sleep during the procedure so that you won't feel any pain from the shocks. You may receive other medications through the IV to help restore your heart rhythm.

A nurse or technician places several large patches called electrodes on your chest. The electrodes connect to a cardioversion machine (defibrillator) using wires. The machine records your heart rhythm and delivers shocks to your heart to restore a normal heart rhythm. This machine can also correct your heart's rhythm if it beats too slowly after cardioversion.

Once you're sedated, electric cardioversion usually takes only a few minutes to complete.

After the procedure

Electric cardioversion is done on an outpatient basis, meaning you can go home the same day your procedure is done. You'll spend an hour or so in a recovery room being closely monitored for complications.

You'll need someone to drive you home, and your ability to make decisions may be affected for several hours after your procedure.

Even if no clots were found in your heart before your procedure, you'll take blood-thinning medications for at least several weeks after your procedure to prevent new clots from forming.


For most people, cardioversion can quickly restore a regular heartbeat. It's possible you'll need additional procedures to keep a normal heart rhythm.

Your doctor may suggest lifestyle changes to improve your heart health and prevent or treat conditions that can cause arrhythmias, such as high blood pressure.

  • Avoid or limit caffeine and alcohol
  • Eat heart-healthy foods
  • Increase your physical activity
  • Maintain a healthy weight
  • Quit smoking
  • Try to limit or manage stress and anger
  • Use less salt, which can help lower blood pressure

Content Last Updated: May 30, 2020

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