Electrical Cardioversion

Electrical Cardioversion

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Electrical Cardioversion

Cardioversion is a procedure that is done to return your heartbeat to a normal rhythm. It’s done when the heart is beating very fast or irregular. This is called an arrhythmia. During the procedure, a low-energy shock is sent to the heart to reset it to a normal rhythm. This is done with a small machine that sends electric shocks to electrode pads on your chest. Cardioversion is not the same as defibrillation. Both use shocks to reset the heart. But defibrillation uses a stronger shock to change a severe arrhythmia that can cause sudden death.

Cardioversion is most often a scheduled procedure. But in some cases, it may be done as an emergency treatment. This is done if symptoms are severe. You will be given medicine to let you sleep through the procedure.

When electrical cardioversion is used

An arrhythmia can cause problems such as fainting, stroke, heart attack, and even sudden cardiac death. Electrical cardioversion can help treat several kinds of arrhythmias.

It is often used to treat atrial fibrillation (AFib). With this condition, the top chambers of the heart (atria) quiver instead of beat normally. Symptoms of AFib may include shortness of breath, fatigue, and a very fast heartbeat. It can also increase risk for stroke. But your health care provider may not want you to have cardioversion if you have minor symptoms from AFib. It also may not be advised if you are an elderly adult, if you have had AFib a long time, or if you have other major health problems. Other treatments may be better for you, such as heart rate control with medicine.

Electrical cardioversion is also used for treating other arrhythmias. These include atrial flutter, which is similar to AFib but not as severe. It can also be used to treat certain kinds of atrial tachycardia (AT) and ventricular tachycardia (VT). These arrhythmias can cause heart rates that are too fast. This can prevent the heart from pumping enough blood.

Risks of electrical cardioversion

Every procedure has risks. The risks of electrical cardioversion include:

  • Creating other kinds of arrhythmias that are less dangerous

  • Temporary low blood pressure

  • Heart damage (often temporary and with no symptoms)

  • Heart failure

  • Dislodged blood clot that can cause stroke, pulmonary embolism, or other problems

  • No success resetting the heart to a normal heart rhythm

  • Return to the original arrhythmia shortly after the procedure

In rare cases, the procedure can cause a more dangerous heart rhythm. If that happens, you will be given medicine or a stronger electric shock to stop this rhythm.

In some cases, health care providers lower the risk for blood clots by giving medicine called a blood thinner to help prevent them. You may be given this medicine before and after the procedure.

Your own risks may vary based on your age, the type of arrhythmia you have, and your overall health. Ask your health care provider which risks apply most to you.

Getting ready for your procedure

Talk with your health care provider about how to get ready for your procedure. Tell him or her about all the medicines you take. This includes over-the-counter medicines such as ibuprofen. It also includes vitamins, herbs, and other supplements.

Follow your health care provider’s instructions about what medicines to take before the procedure. This includes medicines that prevent arrhythmias. Don’t stop taking any medicine unless your health care provider tells you to.

You may need blood tests before the procedure. This is to make sure the procedure is safe for you.

You may have a transesophageal echocardiography test before the procedure. This test is a special kind of ultrasound. A thin, flexible tube is put down your throat and into your esophagus. There, the tube is close to your heart. It lets your health care provider see if you have any blood clots. Your cardioversion will be delayed if a clot is found.

You’ll be at a higher risk for blood clots, so your health care provider may want you to take blood thinner medicine. You may take this several weeks before and after the procedure.

Make sure to:

  • Ask a family member or friend to take you home from the hospital. You cannot drive yourself.

  • Don’t eat or drink after midnight the night before your surgery, unless your health care provider says it’s OK.

  • Follow all other instructions from your health care provider.

You may be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully. Ask questions if something is not clear.

On the day of your procedure

Ask your health care provider about the details of your procedure. The procedure only takes a few minutes. It may be different when done as an emergency treatment. In general, you can expect the following:

  • Soft electrode pads are stuck to your chest, and may be stuck on your back. These areas of skin may be shaved. This is to help the electrode pads stick.

  • Wires will be attached to the electrodes. The wires connect to a cardioversion machine.

  • You will receive medicine through a vein in your arm. This is to make you fall asleep.

  • The cardioversion machine sends a low-energy shock to your heart. This should convert your heart back to a normal rhythm. You won’t feel any pain.

  • Your health care team will closely watch your heart rhythm. They will watch for any signs of problems.

  • When it is done, you will wake up.

After your procedure

You will wake up 5 to 10 minutes after the procedure. You’ll be closely watched for signs of problems for several hours. You will likely go home the same day. You may feel sleep for several hours because of the sedation. You will need to have a family member or friend drive you home. Your chest may be red or sore for a few days.

You may need to take blood thinner medicine, such as warfarin, for several weeks after the procedure. Take this exactly as directed. You may also need to take a medicine to prevent arrhythmias. Take all your medicines exactly as directed.

Follow-up care

Make sure to keep all of your follow-up appointments.


When to call your health care provider

Call your health care provider right away if you have any of these:

  • Trouble breathing or chest pain (call 911)

  • Dizziness

  • Fainting