What is external cardioversion?

External cardioversion is a procedure to restore your heart rhythm back to a normal rhythm. This procedure is often used for atrial fibrillation, atrial flutter, ventricular tachycardia and ventricular fibrillation.

This can provide relief from the symptoms of these conditions which include palpitations, tiredness and breathlessness. 

What does external cardioversion involve?

External cardioversion involves connecting you to a defibrillator machine that gives a controlled electric shock to your heart to make it beat normally again.

The procedure is performed under a short general anaesthetic, so you are asleep throughout. Electrodes connected to a defibrillator machine are placed on your chest, sometimes your chest and back. One or more controlled electric shocks are given to restore a normal heart rhythm.

How should you prepare for an external cardioversion?

Dr Butcher will talk you through the procedure and answer any questions you may have at a consultation before you have treatment. He will also give you detailed instructions on how to prepare for your cardioversion, such as avoiding eating on the day of the procedure.

You may also need to have an ECG, echocardiogram (ultrasound scan of the heart) or wear a heart monitor for 24 hours before having the procedure to check that your heart rhythm is still abnormal. Dr Butcher will arrange this for you. 

You should come to your appointment wearing little or no jewellery as you will be asked to remove it. You should also avoid applying any oils or moisturisers to your chest. The procedure itself takes around 10 minutes to perform but you should plan to spend around four to six hours in total in hospital to allow time for procedure preparation and your recovery.

What are the risks associated with an external cardioversion?

Risks of external cardioversion are rare. However, the potential risks of the procedure to be aware of include:

• Blood clots 
• Minor burns and chest discomfort at the site of the electrode pads 
• Nausea from the anaesthetic
• Dizziness from a drop in blood pressure

Dr Butcher will talk you through any potential complications before the procedure and answer any questions you have.

What is the recovery process for an external cardioversion?

After the procedure, you will spend an hour or so in the recovery room where you will be monitored closely. You will feel sleepy as the anaesthetic wears off and may feel some aching and tenderness in your chest. 

The external cardioversion is performed as an outpatient procedure, so you will be able to go home on the same day. However, it is important that in the first 24 hours after your treatment you do not drink alcohol, drive, or operate heavy machinery, while the anaesthetic wears off completely. 

Dr Butcher will review you at a follow-up consultation.