Cardioversion

---

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

---

Definition

The delivery of an electric shock to the chest via electrodes or paddles in order to correct a dangerous heart arrhythmia. An arrhythmia is an abnormality or loss of the heartbeat.

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

Parts of the Body Involved

Chest wall and heart

Reasons for Procedure

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

Elective cardioversion may be used to treat the following conditions:

• Atrial fibrillation - rapid, irregular twitching in the atrium
• Atrial flutter - rapid contractions in the atrium

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

• Ventricular tachycardia - rapid beating of the heart, originating in the ventricle
• Atrial tachycardia - rapid beating of the heart, originating in the atrium
• Ventricular fibrillation - rapid movement of the ventricular muscle

Risk Factors for Complications during the Procedure

• Improperly maintained cardioverter, which delivers more or less charge than intended
• Blood clots in the heart chambers that may be discharged into circulation during cardioversion

What to Expect

Prior to Procedure

Elective cardioversion:

• You will have an electrocardiogram (ECG, EKG) – 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 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 preparation

During Procedure:

• Continuous cardiac monitoring
• IV
• Short-acting, deep sedation or anesthesia (usually no anesthesia can be given for urgent cardioversion)

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 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. After the sedation wears off, you'll be sent home.

How Long Will It Take? Less than 30 minutes

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:

• Resumption of the abnormal rhythm
• Development of a more dangerous arrhythmia
• Stoppage of your heart
• Damage to the heart muscle
• Blood clots introduced into your circulation, leading to such complications as stroke, breathing difficulties, heart attack, 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 - None

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 arrhythmia 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

SOURCE:

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

---

Last reviewed March 2001 by Medical Review Board