Cardioversion

The information on this page is for patients having 'cardioversion' which is a treatment for heart rhythm disturbance. It explains what it is for, what is involved and any significant risks that there may be.

What is a cardioversion?
It is a treatment for heart rhythm disturbances, using an electric shock to the chest to jolt the heart back into its normal rhythm. You will have a brief general anaesthetic so you will be unaware of the shock.

What is it for?
It is to put the heart back into normal rhythm when the heart beat is rapid and the rhythm is abnormal (arrhythmia). This usually occurs when there is atrial fibrillation, this is a very rapid fluttering of the minor chambers of the heart, the right and left atrium. Other rapid arrhythmias may also be corrected by cardioversion and if potentially life threatening (chest pain, lowering of blood pressure or shortness of breath), then cardioversion may be done as an emergency. In most cases, it is a planned procedure.

What are the treatment options?
You should discuss the following options for treatment with your specialist doctor (a cardiologist) to find out which is best for you:

No treatment
Drugs
Cardioversion

If cardioversion is advised then you will see a cardiologist.

Initial treatment and tests before cardioversion
Initially you may be given medication to slow down the heart, such as digoxin or beta blockers particularly if you have atrial fibrillation. Then in the weeks before your cardioversion, you will have some or all of the following tests to identify the possible causes of your abnormal heart rhythm and any associated problems:

A heart tracing (an ECG)
A chest x-ray
An ultrasound scan (an echocardiogram)
Blood tests

You will have the opportunity to discuss the treatment and the recovery with nurses and doctors. Please ask any questions you want to.

Pre-treatment with warfarin
If you have atrial fibrillation, your specialist doctor will usually recommend you have pre-treatement with warfarin (tablets) to thin the blood, starting four to six weeks before the procedure. This is to protect against blood clots forming in the heart, which may then travel to the brain to cause a stroke. The warfarin will be continued after cardioversion for four weeks. If the heart rhythm remains normal then the warfarin can usually be stopped. When taking warfarin, you will need to attend the antocoagulant clinic to have the dose monitored regularly. Warfarin cannot be used in a few patients because of the bleeding risk. For these patients other drugs may be used such as aspirin; but it is ofter necessary to have a trans-oesophaggeal echo scan (see non-invasive tests) with the cardioversion, to make sure there are no blood clots in the atria.

On the day of your cardioversion
Cardiversion is done as a daycase procedure, unless you are already in hospital. Please report to Lewes ward, on level 10 in the tower block. A nurse will record another ECG and check observations such as your blood pressure and temperature. The nurse will prepare you for the procedure and a doctor will obtain your consent and confirm your understanding of the procedure. The specialist doctor and the anaesthetist will visit you before hand. You will be asked to sign a consent form to confirm that you understand the procedure and agree to go ahead with it. You will have a brief general anaesthetic. You will not be aware of the electric shock that is given to the heart. The procedure usually takes about 10 minutes and you will wake up in a recovery room. When you are awake and back on Lewes ward another ECG will be recorded.

	Click on the icon to download the cardioversion admission letter

Going Home
You can usually go home around 2 to 3 hours after the procedure.

You must not drive a car, sign a legal document or operate machinery for 24 hours following the procedure.

You may find your chest a little sore for 2 to 3 days after the procedure.  You can take paracetamol tablets for this discomfort and we may give you some hydrocortisone cream before you go home if your chest is red.

You must have someone to stay with you for 24 hours following the procedure as you may feel drowsy and should rest especially if you feel sick or dizzy.

Please refrain from smoking and drinking alcohol for the rest of the day. You will be sent an appointment for the out-patients clinic in 4 to 6 weeks time.

You should continue with your medications as instructed until your out-patients appointment.

Please continue having your warfarin blood test as instructed by the anti-coagulation clinic.

You will be given a follow up appointment for 4 to 6 weeks post procedure.

If you experience any problems related to the cardioversion you can contact Lewes ward on telephone number: 01273 696955 extension 7852.

If you have any other worries please contact your GP.

You will usually be allowed home about two to three hours after the procedure. You will not have pain following the treatment or need painkillers. A friend or relative must collect you and take you home and stay with you for the first 24 hours. You must not drink alcohol, drive or work machinery (including kettles or cookers) for the first 24 hours following your cardioversion to allow the anaesthetic to wear off.

Are there any risks?
This is a very safe treatment with a success rate of approximately 80%, (greater if the heart is structurally normal and the rhythm upset is recent). but there are some risks assocaited with it such as
a) skin reaction - you may have a mild skin reaction on your chest which will disappear a few days following the treatment, (risk - 10-15% of cases).
b) Recurrence - if the arrhythmia returns days or weeks afterwards, you may be offered another cardioversion along with anti-arrhythmic medication (risk 30-60% of cases). For some patients the risks may be higher; please speak to your specialist doctor before your treatment if you have any concerns about these risks.
c) A stroke is rare (less the 1%) and you will have been taking warfarin to thin your blood to prevent this.