Skip Ribbon Commands
Skip to main content

Electrical Cardioversion

Electrical Cardioversion: Symptoms, Causes and Risk Factors, Diagnosis, Treatments | National Heart Centre Singapore

Electrical Cardioversion - What it is

Cardioversion is a procedure in which an electrical shock is delivered to the heart to convert an irregular or fast heart rhythm (called an arrhythmia) to a normal heart rhythm.

During cardioversion, your doctor uses a cardioverter machine (diagram below) to send electrical energy (or a “shock”) to the heart muscle to restore the normal heart rhythm.

Cardioversion can be used to treat many types of fast or irregular heart rhythms. The most common irregular heart rhythms that require cardioversion include atrial fibrillation and atrial flutter. Life-saving cardioversion may be used to treat ventricular tachycardia and ventricular fibrillation (a rapid, life-threatening rhythm originating from the lower chambers of the heart).

Cardioversion has been recommended by your doctor to restore your heart rhythm to normal, so your heart can pump as it should. It is sometimes done in an emergency setting when fatal arrhythmias occur. 

If the cardioversion procedure is recommended for you, please ask your doctor to discuss the specific risks and benefits of the procedure.

Where will the cardioversion be done?

The procedure will be done in the Coronary Care Unit (CCU).

Cardioversion has been recommended by your doctor to restore your heart rhythm to normal, so you heart can pump as it should. It is sometimes done in an emergency setting when fatal arrhythmias occur. 

If the cardioversion procedure is recommended for you, please ask your doctor to discuss the specific risks and benefits of the procedure.

Is there any other procedure that needed to be done prior to cardioversion?

In cases of atrial flutter and atrial fibrillation, prior to cardioversion, your doctor will discuss the risks and benefits of the procedure. He would also discuss that a pre-procedure transoesophageal echocardiogram needed to be done. This is to rule out the presence of clot in the heart. Presence of a clot would be contraindicated for the cardioversion, as cardioversion increases the chance of dislodging the clot to the brain, causing a stroke.


Electrical Cardioversion - Symptoms

Electrical Cardioversion - How to prevent?

Electrical Cardioversion - Causes and Risk Factors

Electrical Cardioversion - Diagnosis

Electrical Cardioversion - Treatments

Electrical Cardioversion - Preparing for surgery

​Pre-Cardioversion Preparations

Your doctor will arrange a date for you to be admitted to the hospital. Usually you are admitted on the day of the procedure; occasionally, you will be admitted the day before.  

Most patients can expect to be discharged the following day; occasionally, your hospital stay may be longer if the procedure is difficult or complicated.

Do I continue to take my medications till the day of the procedure?

Your doctor should already have instructed you on what to do before the procedure. 

Please check with your doctor before discontinuing any medications. The following information is a general guide only.

Continue to take all of your medications as prescribed on the day of the procedure, unless you have been given other instructions.

If you need to take medications the morning of the procedure, please only drink small sips of water to swallow them. 

When you call for your procedure time, please ask the nurse for specific guidelines about taking warfarin on the day of the procedure.

If you have diabetes, ask the nurse how to adjust your diabetes medications or insulin before the procedure.

Can I eat before the procedure?

In most cases, you will be told to eat a normal meal the evening before your procedure. However, do not eat, drink or chew anything after 12 midnight before your procedure. This includes gum, mints, water, etc. If you must take medications, only take them with small sips of water. When brushing your teeth, do not swallow any water. 

What should I wear?

Wear comfortable clothes when you come to the hospital. You will change into a hospital gown for the procedure. Please leave all jewelry (including wedding rings), watches and valuables at home.

What happens before the procedure? 

Before the procedure begins, a nurse will help you get ready. You will be given a hospital gown to change into. You may keep your clothes in a locker or you may give them to a family member. 

You will lie on a bed and the nurse will start an IV (intravenous) line in a vein in your arm or hand. The IV is used to deliver medications and fluids during the procedure. 

EKG patches and adhesive cardioversion pads will be placed on your chest and sometimes on your back. Men may have their chest hair shaved if necessary.

The nurse will connect you to several monitors that allow the doctors to check your heart rhythm and blood pressure during the procedure. You are continually monitored during the procedure.

During Cardioversion: What to Expect

Will I be awake during the procedure?

No. A medication will be given through your IV to make you fall asleep during the procedure.

How long does the procedure take? What should I expect?

While you are asleep, the doctor will use the cardioverter machine (defibrillator) to deliver specific amounts of energy to your heart through the cardioversion patches. The shock interrupts the abnormal electrical rhythm and restores a normal heart rhythm.

Although the procedure only takes a few seconds, several attempts may be needed to restore the normal heart rhythm.

Overall the procedure itself takes a few minutes. However, the preparation and recovery time for the procedure may take hours. You will be monitored in the CCU until you have recovered.

Electrical Cardioversion - Post-surgery care


Will I have to stay in the hospital?
No. In most cases, you would be able to return home the same day of the procedure.

What should I expect during recovery?
You will gradually wake up after the procedure.
Once you are fully awake, the doctor will tell you if the cardioversion successfully converted your heart rhythm to normal. Your doctor will discuss your medications, other treat ment options and when to return for follow-up appointments. 

Be sure to ask the doctor if you can continue taking your previous medications.

Once you are fully awake, you will be taken to the general ward where you will be offered something to eat and drink. Your family may visit you in this area. Your doctor will tell you when you can go home.

How will I feel after the procedure?
During the first few days after the procedure, you may feel tenderness on your chest wall where the cardioversion pads were placed. 

You may be given a tube of hydrocortisone cream to help relieve skin discomfort on your chest; apply as needed.
The doctor will tell you what over-the-counter medications you can take for pain relief. Please tell your doctor or nurse if your symptoms are prolonged or severe.

The sedation given during the procedure may make you feel drowsy; therefore you should not drive or operate machinery until the day after the procedure.

Will I be able to drive myself home?
No. For your safety, a responsible adult must drive you home. In general, you can resume driving the day after the procedure.

What instructions will I receive before I leave the hospital?
Your doctor will discuss the results of the procedure and answer any questions you have. Be sure to ask the doctor if you can continue taking your previous medications. 

You will receive specific instructions about how to care for yourself after the procedure including medication, activity guidelines and a follow-up schedule. 

Electrical Cardioversion - Other Information

Terms of Use/ Condition Disclaimer

The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

Information provided by Singhealth

Discover articles,videos, and guides afrom Singhealth's resources across the web. These information are collated, making healthy living much easier for everyone.