What is electrical cardioversion?

Electrical cardioversion is a procedure in which a brief electric shock is given to the heart to reset the heart rhythm back to its normal, regular pattern (normal sinus rhythm). The shock is given through patches applied to the outside of the chest wall. In some situations an external defibrillator, which has paddles, might be used.

Usually, the person is sedated. If the person is conscious, medicine is given to control pain and to cause the person to relax to the point of being nearly unconscious during the procedure.

Medicines

• If the doctor gave you a sedative:
  • For 24 hours, don't do anything that requires attention to detail. It takes time for the medicine's effects to completely wear off.
  • For your safety, do not drive or operate any machinery that could be dangerous. Wait until the medicine wears off and you can think clearly and react easily.
• Be safe with medicines. Take your medicines exactly as prescribed. Call your doctor if you think you are having a problem with your medicine. You may take one or more of the following medicines:
  • Rate-control medicines to slow the heart rate.
  • Rhythm-control medicines that help the heart keep a normal rhythm.
  • Blood thinners, also called anticoagulants, which help prevent blood clots.
  You will get more details on the specific medicines your doctor prescribes. Be sure you know how to take your medicines safely.
• Do not take any vitamins, over-the-counter medicines, or herbal products without talking to your doctor first.

Exercise

• Talk to your doctor about what type and level of exercise are safe for you.
• When you exercise, watch for signs that your heart is working too hard. You are pushing too hard if you cannot talk while you are exercising. If you become short of breath or dizzy or have chest pain, sit down and rest right away.
• Check your pulse regularly. Place two fingers on the artery at the palm side of your wrist in line with your thumb. If your heartbeat seems uneven or fast, talk to your doctor.

Heart-healthy lifestyle

• Do not smoke. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
• Eat heart-healthy foods. Limit sodium, alcohol, and sugar.
• Stay at a healthy weight. Lose weight if you need to.
• Manage other health problems. If you think you may have a problem with alcohol or drug use, talk to your doctor.

After this treatment, most people get back a normal heart rhythm right away.

But for many people, atrial fibrillation returns. Normal rhythm may last less than a day or for weeks or months. It depends on a few things. These things include how long you have had atrial fibrillation, what is causing it, and if you have another heart problem.

If you take antiarrhythmic medicines too, they can help you stay in a normal rhythm longer.

If atrial fibrillation returns, talk with your doctor about your treatment options. You may try cardioversion again or you may choose another treatment, such as catheter ablation or medicine.

Procedures can be stressful. This information will help you understand what you can expect. And it will help you safely prepare for your procedure.

Preparing for the procedure

• Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.
• Understand exactly what procedure is planned, along with the risks, benefits, and other options.
• If you take a medicine that prevents blood clots, your doctor may tell you to stop taking it before your procedure. Or your doctor may tell you to keep taking it. (These medicines include aspirin and other blood thinners.) Make sure that you understand exactly what your doctor wants you to do.
• Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your procedure. Your doctor will tell you if you should stop taking any of them before the procedure and how soon to do it.
• Make sure your doctor and the hospital have a copy of your advance directive. If you don’t have one, you may want to prepare one. It lets others know your health care wishes. It’s a good thing to have before any type of surgery or procedure.

Risks of the procedure include the following:

• A blood clot may become dislodged from the heart and cause a stroke. Your doctor will try to decrease this risk by using anticoagulants or other measures.
• The procedure may not work. You may need another cardioversion or other treatment.
• Antiarrhythmic medicines used before and after the procedure or even the procedure itself may cause a life-threatening irregular heartbeat.
• You could have a reaction to the medicine given to you before the procedure. But harmful reactions are rare.
• You can get a small area of burn on your skin where the patches are placed.

After cardioversion, you will be monitored to make sure that you have a stable heart rhythm.

You might take a medicine (called a blood thinner) that prevents blood clots before and after the procedure. This medicine lowers your risk of a stroke.

Other medicines to help prevent the return of heart rhythm problems (antiarrhythmics) also may be given before and after the procedure.

Electrical cardioversion is a treatment for an abnormal heartbeat, such as atrial fibrillation, supraventricular tachycardia, or ventricular tachycardia (VT). Your doctor used a brief electrical shock to reset your heart's rhythm.

After the procedure, you may have redness, like a sunburn, where the patches were. The medicines you got to make you sleepy may make you feel drowsy for the rest of the day. You may feel soreness or discomfort in your chest wall for a few days.

Your doctor may have you take medicines to help the heart beat normally and to prevent blood clots.

Cardioversion is used:

• As a non-emergency procedure to stop a heart rhythm problem that has not stopped on its own. These heart problems include atrial fibrillation, atrial flutter, and supraventricular tachycardia.
• As an emergency procedure to stop a fast heart rate that is causing low blood pressure or severe symptoms. These heart rate problems include atrial fibrillation, atrial flutter, supraventricular tachycardia, and ventricular tachycardia.

• Follow the instructions exactly about when to stop eating and drinking. If you don't, your procedure may be canceled. If your doctor told you to take your medicines on the day of the procedure, take them with only a sip of water.
• Take a bath or shower before you come in for your procedure. Do not apply lotions, perfumes, deodorants, or nail polish.
• Take off all jewelry and piercings. And take out contact lenses, if you wear them.

At the hospital or surgery center

• Bring a picture ID.
• You will get medicine to make you sleepy.
• The electrical part of cardioversion takes about 5 minutes. But you may be in the hospital for a few hours to recover.