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What is cardioversion?

Cardioversion is a procedure to correct arrhythmias, which is when your heart beats too fast or irregularly. Arrhythmias may prevent your body from getting the blood and oxygen it needs. Cardioversion delivers a shock of electricity to your heart to help it return to its normal rhythm. Your heart has 4 chambers called the atria and ventricles. The atria are at the top of your heart, and the ventricles are at the bottom of your heart. Most arrhythmias that need cardioversion start in the atria of your heart.

What may I need before cardioversion?

  • Medicines:
    • Blood thinners: This medicine helps prevent clots from forming in the blood. Clots can cause strokes, heart attacks, and be life-threatening. Blood thinners make it more likely for you to bleed or bruise. Use an electric razor and soft toothbrush to help prevent bleeding.
    • Heart medicine: This helps make your heart more sensitive to the electrical charge so it responds to cardioversion.
  • Blood tests: A sample of your blood may be sent to the lab for tests to find the cause of your symptoms. Blood tests may also be used to make sure organs, such as your liver and kidneys, are working correctly.
  • Transesophageal echocardiogram: This is a type of ultrasound that shows pictures of how your heart moves when it beats. It may also show blood clots in your heart. You will be given medicine to help you relax. Caregivers put a tube in your mouth that is moved down into your esophagus. The tube has a small sensor on the end that lets caregivers check your heart.

What happens during cardioversion?

You will be given medicine that makes you sleepy and relaxed before your procedure. You may also get anesthesia medicine to help you stay asleep during the procedure. During cardioversion, your caregiver sends an electrical shock to your heart muscle. The shock is given at a certain time during your heartbeat that will best help it return to normal. Your heart may need to be shocked more than once to help it return to its normal rhythm. You may need one of the following:

  • External cardioversion: This procedure uses paddles or gel pads to shock your heart. Two pads will be placed on your chest, or one will be on your chest and one on your back. Your caregiver will watch your heart beat on a monitor for the right time to deliver the shock. After the shock is given, your heartbeat will be checked. If your heart continues to beat abnormally, another shock will be given.
  • Internal cardioversion: This procedure uses catheters (thin, flexible tubes) that are put into your heart. Your caregiver inserts the catheters through a vein (blood vessel) and into your heart. An x-ray may be used to check the location of the catheter. The electric shock is then given through the catheters.

What happens after cardioversion?

You will be taken to a room where you can rest until you are fully awake. Do not get out of bed until your caregiver says it is okay. Caregivers will monitor your heart rhythm and watch you closely for any problems. When caregivers see that you are okay, you may be able to go home. If you are staying in the hospital, you will be taken back to your room.

What are the risks of cardioversion?

  • The electric shock used may cause burns on your skin. If you have internal cardioversion, you may bleed or get an infection. Treatment may cause a blood clot to travel to your heart or brain and cause life-threatening problems, such as a heart attack or stroke. Even with cardioversion, your heart may not return to or stay in a normal heart rhythm. You may develop other arrhythmias that need treatment.
  • Without treatment, your arrhythmia and symptoms, such as chest pain and tightness, may get worse. You may have worsening weakness, dizziness, and trouble breathing. Arrhythmias that are not treated can increase your risk of heart failure or a heart attack. Arrhythmias also increase your risk for blood clots and a stroke. These conditions may be life-threatening.

When should I contact my caregiver?

Contact your caregiver if:

  • You have a fever.
  • You have questions or concerns about your condition or care.

When should I seek immediate care?

Seek care immediately or call 911 if:

  • You feel like your heart is fluttering or jumping in your chest.
  • You feel lightheaded or you have fainted.
  • You have chest pain when you take a deep breath or cough. You may cough up blood.
  • You have discomfort in your chest that feels like squeezing, pressure, fullness, or pain.
  • You have pain or discomfort in your back, neck, jaw, stomach, or arm.
  • You have weakness or numbness in part of your body.
  • You have sudden trouble breathing.
  • You become confused or have difficulty speaking.
  • You have dizziness, a severe headache, or vision loss.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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