What Is Cardioversion?

Cardioversion is a way to restore your heart’s normal rhythm. When your heartbeat is irregular, medi­cine is often used first to try to correct the rhythm of your heart. If that doesn’t work, cardioversion may be the next step. During this procedure, you are given a small, brief electric shock by a doctor. The shock helps your heartbeat become normal again. Cardioversion is most often done in a hospital.

The electrocardiogram (ECG) test results below show the difference between an irregular heartbeat and a heartbeat that has been restored to normal using cardioversion.

An ECG showing an irregular heartbeat before cardioversion.

An ECG showing a heartbeat restored to normal with cardioversion.

Before Your Procedure

Be sure to tell the doctor what medicines you take. Your doctor may ask you to take anticoagulants (blood thinners) for a few weeks—this helps prevent blood clots from forming. Your doctor will explain to you why you need cardioversion, as well as any risks. You will also be asked to sign a consent form. On the day of the procedure, don’t eat or drink for 6 hours before going to the hospital. And be sure to follow any other instructions you are given.

Don’t eat or drink for 6 hours before your procedure. If you have been told to continue with any medication, take it only with small sips of water.

During Your Procedure
Small pads (electrodes) are placed on your chest to record your heartbeat at all times.

  • An intravenous (IV) line is placed in your arm to give you a drug to sedate you (make you sleepy). You will not feel any discomfort during the procedure.
  • You may be given oxygen through a soft plastic tube in your nose.
  • Then, a very brief, low-dose electric shock is given through pads on your chest and back.
  • Your heartbeat is watched to make sure the normal rhythm has been restored.

During  cardioversion, you are fully sedated and won’t feel a thing.

After Your Procedure

You’ll need to stay in the hospital until the doctor is sure your heart­beat is normal

again. That might mean until the next day. You’ll wear a special monitor during this time. But you can sit up, walk, and have something to eat as soon as you are fully alert. For a day, the skin on your chest may feel a little sore, like a mild sunburn.

As soon as you’re alert, you may eat again.