�Diagnostic and Surgical Procedures

Cardioversion

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Definition | Body Parts Involved | Reasons for Procedure | Complications | What to Expect | Outcome | Call Doctor If

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En Espa�ol (Spanish Version)

Definition

The delivery of an electric shock to the chest via electrodes or paddles in order to correct a dangerous heart dysrhythmia. A dysrhythmia is an abnormality of the heartbeat which may be either a faster or slower than normal rate.

Cardioversion can be done as an elective (scheduled) procedure, or may be done urgently if a dysrhythmia is immediately life threatening.

Parts of the Body Involved

Chest wall and heart

Reasons for Procedure

Certain heart disrhythmias may prevent the normal circulation of blood through the body, and may deprive various organs, including the brain and heart, of oxygen.

Non-emergency cardioversion may be used to treat the following conditions:

• Atrial fibrillation - very rapid, irregular twitching in the atrium, when the ventricular heart rate is not too fast
• Atrial flutter - rapid but regular contractions in the atrium, when the ventricular heart rate i snot too fast

Emergency cardioversion may be used to treat the following types of disrhythmias, which can lead to death if they are not immediately converted to a more normal rhythm:

• Atrial tachycardia - rapid beating of the heart, originating in the atrium with rapid ventricular heart rate
• Ventricular tachycardia - rapid beating of the heart, originating in the ventricle
• Ventricular fibrillation - rapid movement of the ventricular muscle without effective beats

Risk Factors for Complications During the Procedure

• Blood clots in the heart chambers that may be dislodged into the circulation during cardioversion

What to Expect

Prior to Procedure

Elective cardioversion:

• You will have had an electrocardiogram (ECG, EKG) to diagnose the condition� a test that records the heart's activity by measuring electrical currents through the heart muscle
• You may be given blood thinners for several weeks prior to non-emergency cardioversion
• You may undergo transesophageal echocardiogram to evaluate the presence of blood clots in the heart
• Arrange for a ride to and from the procedure
• Arrange for help at home after the procedure
• The night before, eat a light meal and do not eat or drink anything after midnight
• Do not take digoxin the morning of the procedure

Urgent cardioversion: no time is available for advance preparation

During Procedure:

• You will have continuous cardiac monitoring
• An intravenous line will be placed to administer medications or fluids as needed
• Short-acting, deep sedation or anesthesia

Anesthesia - Short-acting general, or brief, deep sedation

Description of the Procedure - Electrodes or paddles are applied to the chest. An electric charge is delivered through these electrodes or paddles to the chest and into the heart. This momentarily stops the electrical activity of the heart and allows the heart to reset itself into a normal rhythm. This may need to be repeated several times, with a gradually increasing electric charge.

After Procedure - You'll be monitored closely in a recovery room or in the coronary care unit of the hospital. If you had non-emergency cardioversion, after the sedation wears off and once you are in stable condition, you'll be sent home.

How Long Will It Take? The procedure itself is usually less than 30 minutes. You will need to be monitored for at least several hours after the procedure.

Will It Hurt? Anesthesia prevents pain during the procedure. If you have urgent cardioversion, you may still be unaware of the pain involved, or you may feel a jolt that some people liken to a kick in the chest.

Possible Complications:

• Inabilitiy to stop the abnormal rhythm
• Resumption of the abnormal rhythm after a normal rhythm was established
• Development of a more dangerous disrhythmia
• Damage to the heart muscle
• Blood clots introduced into your circulation, leading to such complications as stroke, or damage to your intestines, kidneys, or limbs
• Burning or irritation to the skin of the chest where the paddles or electrodes are applied

Average Hospital Stay - Elective procedures are usually performed in a monitored outpatient setting, and most people can go home later that day. People who need emergency cardioversion may be admitted to the hospital for further observation, or because of the illness that caused the event.

Postoperative Care - You may be put on blood thinners for a few weeks after undergoing cardioversion (in which case blood levels of these medications will need to be monitored via blood tests, usually weekly). You may also be put on a medication called an anti-arrhythmic, which will help prevent the disrhythmia from recurring.

Outcome

Cardioversion usually results in a more normal heart rhythm

Call Your Doctor If Any of the Following Occurs

• Blisters, redness, or open sores on your chest
• Lightheadedness, dizziness
• Confusion
• Sensation of your heart fluttering (palpitations)
• Sensation of a skipped or missed beat, or an irregular pulse
• Cough, difficulty breathing, shortness of breath
• Severe nausea or vomiting
• Chest pain or pain in your left arm or jaw
• Pain in your abdomen, back, arms, or legs
• Blood in your urine
• Changes in vision or speech
• Difficulty walking or using your limbs
• Drooping facial muscles

RESOURCES:

American Heart Association
http://www.americanheart.org/presenter.jhtml?identifier=1200000

National Heart, Lung, and Blood Institute
http://www.nhlbi.nih.gov/index.htm

SOURCE:

Procedures for Primary Care Physicians, 1st ed. Mosby-Year Book, Inc., 1994.

Triage Reviewed by EBSCO Medical Review Board in September 2005