This page describes cardioversion, a procedure used in the treatment of atrial fibrillation. If you or a family member have any additional questions, please feel free to discuss them with your doctor or nurse at any time.

The purpose of the cardioversion procedure

Your doctor has recommended that you have a cardioversion procedure because you have cardiac arrhythmia, or atrial fibrillation (AF). AF causes an irregular - usually fast - heart rhythm. The purpose of the procedure is to convert your heart rhythm from atrial fibrillation to sinus rhythm (your heart's normal rhythm).

What is atrial fibrillation?

Atrial fibrillation is a heart rhythm disturbance that occurs when there is an abnormality in the atrial chambers, or the SA node. AF is rare in younger individuals and the chances of it occurring greatly increase after age 60. Between the ages of 60 to 65, 4 in 100 people have atrial fibrillation. For those over 65 years of age, the chances increase to 10 in 100. There are many causes, including: valvular heart disease, coronary artery disease, lung disease, thyroid disease and major surgical procedures. About 15% of patients with atrial fibrillation have no known cause.

Symptoms of arrhythmia include: dizziness, fainting, palpitations and a "fluttering" feeling in the chest.

Having a stroke is the number one danger in patients with atrial fibrillation. Because of the irregular rhythm, the heart does not pump effectively. This can cause blood to pool in the heart and form clots. These clots can then travel through the bloodstream and cut off or decrease circulation in the blood vessels. When this occurs in the brain, the result is a stroke.

In addition, long-term atrial fibrillation may result in stretching or elongating the heart muscle, causing the heart to pump less effectively, which decreases the amount of blood going to all parts of the body.

Treatment

Your cardiologist studies heart rhythms, identifies arrhythmias and pinpoints their origin in the heart. In treating atrial fibrillation, your cardiologist attempts to eliminate the cause, thus restoring a regular heart rate and controlling rapid heart rates. Common treatment options include:

• Antiarrhythmic medications
• Blood thinners
• Cardioversion

In some cases, it is impossible to restore a normal heart rhythm to a patient with atrial fibrillation despite vigorous treatment. Every patient is unique and a variety of circumstances will determine the success of the treatment.

Medication

Antiarrhythmic medications are usually prescribed to control your heart rate. To reduce the possibility of stroke, your medication may include blood-thinning drugs.

Pre-procedure instructions

On the day of your procedure:

• Do not eat or drink 6 hours before your cardioversion.
• Take your regular medication in the morning as you normally would with small sips of water unless directed otherwise by your doctor.

What happens during the procedure?

Cardioversion is usually performed on an outpatient basis at the hospital. Admission to the hospital is generally not required.

• You will be lying in bed during and after the procedure.
• Small electrodes will be placed on your chest to monitor your heart rhythm.
• An intravenous line will be placed in your arm to allow the anesthesiologist to give you medication to make you sleepy.
• You will be given oxygen, either through a mask or through a soft plastic tube in your nose.
• Your doctor will administer a brief, low-dose electric shock through pads on your chest and back. You will be asleep during this time and will not feel any pain.
• Your heart rhythm will be monitored to ensure that normal rhythm has been restored.

What happens after the procedure?

• You will remain in the hospital for 2 to 4 hours to monitor your heart rhythm and ensure that it remains normal.
• During this time you may sit, walk, and have something to eat or drink as soon as you are fully alert.
• For a day or two after the procedure, the skin on your chest may feel a little sore, like a mild sunburn. Your doctor may prescribe a cream or lotion for this.
• Once you are home, you may resume your normal activities.
• Continue to take all of your medications as prescribed until you see your doctor.
• Call your doctor for a follow-up appointment within 1 - 2 weeks.
• If your irregular heartbeat returns and you feel skipped beats, a rapid heartbeat, or tightness in your chest, call your doctor.

Complications

There is a 2% chance that a stroke-causing blood clot can occur if a person has had atrial fibrillation for more than four days, or if he or she has not received blood thinners before the procedure. Complications are greatly reduced by the use of blood-thinning medications. The doctors and nursing staff are highly skilled and are prepared to act immediately in the event of any complication.