What is a Cardioversion?

A procedure used to convert an irregular heart rhythm to a normal heart rhythm by applying high energy shock.

Your doctor uses cardioversion to convert an irregular or fast heart rhythm back to a normal rhythm. Common rhythms that require cardioversion include atrial fibrillation and atrial flutter. Life-saving cardioversion may be used with ventricular tachycardia.

What Can I Expect?

• Do not eat or drink anything after midnight the evening before your test. If you must take medications, drink only small sips of water to help you swallow your pills.
• Take all your medications as prescribed. If you are diabetic, check with your doctor about how to adjust your diabetic medications. If you are on a blood thinner (anticoagulant), your doctor may tell you to stop taking this medication several days before your procedure.
• Wear comfortable clothes. You will wear a hospital gown during the procedure.
• Most likely, you will be able to go home after the test. You should bring someone with you to drive you home after the test.
• You will lie on a bed and the nurse will start an intravenous (IV) line into your arm or hand. This is so you may receive medications and fluids during the procedure.
• The nurse will connect you to several monitors. Electrode patches will be attached to your chest and upper back. Men may have their chest hair shaved for electrode placement.
• A medication will be given to you through your IV to make you fall asleep.
• While you are asleep, the doctor will use a special machine (defibrillator/cardioverter/pacemaker) that delivers specific amounts of energy through the patches to your heart muscle to restore a normal heart rhythm. Although this procedure only takes a few seconds, several attempts may be needed.
• Internal cardioversion may be used in people whose heartbeat did not return to normal after external cardioversion. Internal cardioversion works by delivering an electric shock through soft wires (catheters) placed in the heart.

In some people, a moderately invasive imaging test called a transesophogeal echocardiogram (TEE) may be performed prior to the cardioversion to make sure the heart is free from blood clots.

The TEE is performed by swallowing a narrow tube with a camera at its tip that can be placed against the back wall of the heart. (Click here to learn more about TEE).

After the Procedure:

• You will gradually wake up. Your nurse or doctor will tell you whether the cardioversion was successful in converting your heart rhythm to normal.
• Your doctor will discuss your medications, when to return for follow-up appointments and other treatment options with you, if necessary.
• You may go home after the procedure. A companion should drive you home.
• Some chest wall tenderness may be present for a few days after your cardioversion. Your doctor will tell you what creams or over-the-counter medications may be helpful to relieve the discomfort.
• If you have any questions about your cardioversion, ask your doctor.