What We Do

A Cardioversion involves sending a low-voltage shock to your chest to convert irregular or rapid heart rhythms to safe ones.

Cardioversions are done under light anesthesia and monitoring and are same-day admission/discharge.​

 Materials and Resources to Help You

The Patient & Family Education Program at UHN offers valuable resources to help you understand your condition.

Resources from the Patient & Family Education Program

Visit our Health Information section to find dedicated resources to help you understand your condition. Find the information you're looking for.​

 Your Procedure

How to Prepare

Sometime before your procedure, your doctor or nurse coordinator will review your medical history with you. They will also explain the purpose of Cardioversion, its potential benefits and possible risks.

Although cardioversion is a safe, low-risk procedure that is done on a regular basis, it can be associated with a small risk of stroke. In order to minimize this risk, you will be asked to take blood thinners for at least one month before to the procedure.

At least 1 week before your cardioversion, you will be scheduled for a preadmission appointment. This appointment will last approximately 3 hours.

You will need to have a blood test, ECG, chest x-ray, and an echocardiogram.

You will be seen by the anesthetist during your preadmission appointment. If this has not been arranged prior to your procedure, then call the Triage Office. If you have any questions, call your doctor's office or call the Triage Office at 416 340 4800 ext. 8436.

If there are any changes in the booking of your procedure, you will be called by the Triage Office or the preadmission booking office.

If you cannot make it to your preadmission appointment or procedure, call the Triage Office at 416 340 4800 ext. 8436 or the preadmission booking office at 416 340 4800 ext. 8691 as soon as you know.

Take a shower the night before or the morning of your cardioversion.

Please bring with you all of your current medications, in their original containers. This includes prescription medications, over-the-counter medications, vitamin or mineral supplements and herbal remedies.

You can have NOTHING to eat or drink from midnight the night before your procedure. Your doctor or nurse coordinator will tell you which medications you are allowed to take on the morning of the procedure. Medications can be taken with a sip of water unless you are instructed otherwise by your doctor. Your doctor or nurse coordinator will give you instructions about your blood thinner or diabetes pills.

If you take a blood thinner such as Coumadin® or Warfarin, please ensure that you have weekly checks of the INR (test required for dosing of Coumadin®/ Warfarin) for 4 weeks before to the planned procedure. Please have your doctor or Lab fax the INR results to Sue Jenkins, in the Thrombosis Clinic, at 416 340 5682.

If you taking blood thinners such as Pradaxa® (Dabigatran), Eliquis®, Apixaban and Xarelto® (Rivaroxaban), please take the medication as prescribed by your doctor. Also, please ensure that you do not miss doses of your medication in the 4 weeks prior to your procedure. Missed doses may increase your risk of stroke, and result in your procedure being postponed.

If you take medication (including pills or insulin) for diabetes, you will be given instructions at your preadmission appointment regarding these medications.

If you need an interpreter, bring a friend or family member who has to be present in the lab for the test. You'll be sedated during this procedure. The friend or family member will be instructed on how to care for you after the exam and be required to drive and/or accompany you home. They can also help you gather information, take notes and ask questions.

You will be discharged the same day unless unforeseen circumstances require you to stay overnight. You may need to arrange for someone to stay with you during the night after you have had your procedure.

Checking In

Your procedure will be done in the Post Anesthetic Care Unit (PACU) on the 2nd floor Eaton Building, however, you will initially check in at the Surgical Admission Unit on the 2nd Floor Munk Building.

Please have the following ready:

  • Health card (OHIP card). If you do not have an OHIP card, please bring another form of government-issued photo ID (such as a driver's license, passport, or other provincial health card). Please arrive 15 minutes before your appointment.
  • Your name, address and birth date

Before Your Cardioversion

When you check-in, the receptionist will give you a name band to wear. You will be assigned a room to wait until it's time for your procedure. You will be asked to change into a hospital gown. Your family should keep your valuables with them.

When you have finished changing, a nurse will prepare you for the test and the physician will once again explain the procedure and ask for your consent (consent is usually given during your preadmission appointment).

Cardioversion is done by placing paddles or patches (called electrodes) on your chest. The electrodes will be connected to the cardioversion machine (called a defibrillator), using wires and the machine will record your heart rhythm and restore your heart rhythm to normal. It may be necessary to remove hair from your chest area so the electrodes have good contact with your skin during the procedure.

The anesthetist will give you a mild general anesthetic through the intravenous (IV) to put you to sleep.

During and After Your Cardioversion

Once you are asleep, you will receive a low-voltage shock from the patches/paddles that were placed on your chest. The shock will stop your heart's electrical activity for a split second. When the heart's electrical activity resumes on its own, normal rhythm should be restored. You won't feel any pain during the procedure.

When you wake up from the anesthetic, you will be in the recovery room for approximately 30 minutes before returning to your room in the Cardiac Short Stay Unit. Your doctor will speak to you following the cardioversion.

When you return to your room, you will be allowed to have something to eat and drink. You will be connected to a monitor until you leave the hospital, that tracks your heart and its activity. You will be asked to take your medications. The nursing staff will monitor your blood pressure and heart rhythm. You will be asked to walk around the nursing unit. You may see the doctor again.

The Results of Your Cardioversion

Your doctor will speak to you following the cardioversion. Prior to discharge, you will be given specific instructions by your doctor or nurse coordinator, regarding your medications.

How Long Will Your Appointment Be?

Cardioversion is scheduled in the morning and only takes a few minutes, however, you will be here until after lunch.​

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