Cardioversion is a medical procedure done to restore a normal heart rhythm for people who have certain heart rhythm disorders such as atrial fibrillation.

Cardioversion is most often done by sending electric shocks to your heart through electrodes placed on your chest (electrical cardioversion). Occasionally, your doctor may perform cardioversion using only medications to restore your heart's rhythm.

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

You generally can't eat or drink anything for 12 hours before your procedure. Your doctor will tell you whether you should 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, which can be dislodged by cardioversion, causing life-threatening complications. Your cardiologist will decide if you need a transesophageal echocardiogram before cardioversion.

In a transesophageal echocardiogram, your throat is numbed and a flexible tube (catheter) with a transducer attached is guided down your throat and into your esophagus, which connects your mouth to your stomach. From there, the transducer can obtain more-detailed images of your heart so that your doctor can check for blood clots.

If your doctor finds blood clots, your cardioversion procedure will be delayed for a few weeks while you take blood-thinning medications to reduce your risk of complications.

During the electrical cardioversion procedure

A nurse or technician will place several large patches called electrodes on your chest. The electrodes will be connected to a cardioversion machine (defibrillator) using wires.

The defibrillator will record your heart rhythm throughout the procedure and will deliver shocks to your heart to restore a normal heart rhythm. This machine can also pace your heart if it beats too slowly after cardioversion.

Before the shocks are delivered, a nurse or technician will insert an intravenous (IV) line in your arm. The IV line is used to give you medications that will make you sleep during the procedure so that you won't feel any pain from the shocks. Your doctor may also use the IV line to give you additional medications that can help restore your heart rhythm.

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

After the procedure

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

Because you'll be asleep for the procedure, your awareness of your surroundings may be affected afterward. 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 usually take blood-thinning medications for several weeks after your procedure to prevent new clots from forming. Some people also may be prescribed medications to help prevent future heart rhythm problems.

Results

For most people, cardioversion can quickly restore a regular heartbeat. However, the atrial fibrillation rhythm may return in the future. It's possible that you will need to have repeat procedures to keep a normal heart rhythm. You also may need to take medications to help maintain a normal heart rhythm.

Mar. 21, 2014