Doctor about to perform cardioversion

Cardioversion is a treatment which aims to get your abnormal heart rhythm (arrhythmia) back to a normal pattern.

It’s done by sending electric signals to your heart through electrodes placed on the chest. 

What happens during a cardioversion?

During the cardioversion procedure:

  • you'll be given a short-acting general anaesthetic or heavy sedation so you will be asleep throughout 
  • a doctor or nurse will put electrodes, stuck to large sticky pads, on your chest
  • the electrodes are connected to a defibrillator machine and will give you one or more controlled electric shocks to your chest wall
  • the defibrillator monitors your heart rhythm throughout the procedure so the medical staff can see straight away if the cardioversion was successful.

The whole procedure usually lasts about 10 minutes.

Do you have a cardioversion treatment coming up? Watch the below video to find out what to expect.

How long will I be in hospital for cardioversion?

You will usually only need to go to hospital for part of the day, although some people need to stay overnight depending on their medical condition.

Are there complications of cardioversion I should be aware of?

Complications aren't common and if you experience any side effects after the cardioversion, they will usually be temporary. 

After your cardioversion, you may get headaches and dizziness from a drop in your blood pressure. You may also feel a small amount of discomfort in your chest where the shock was given. Feeling sick is also a common side effect of an anaesthetic.

How successful are cardioversions?

Cardioversion doesn’t always restore normal heart rhythm. Sometimes it’s successful to start with, but then your abnormal heart rhythm could come back several days, weeks or even months later. If this happens, your doctor may want to repeat the cardioversion or they may consider another treatment for you. 

Who can I talk to about my heart and circulatory condition?

It’s natural to feel worried about having a heart treatment, but it often helps to talk about your feelings with someone close to you or with a healthcare professional. You can use the following ways to get support for the emotional effects of having a heart and circulatory condition:

  • Talk to your GP about being referred for counselling or Cognitive Behavioural Therapy.
  • Call us on 0300 330 3311 to speak to one of our nurses on our Heart Helpline between 9am – 5pm, Monday to Friday.
  • Join our online community platform, HealthUnlocked. Members include those who have been affected by the same condition.

Researching abnormal heart rhythms

Your donations help us fund vital research into the causes and treatment of heart and circulatory conditions, including the work of BHF Professor Barbara Casadei, who is pioneering work to improve our understanding of atrial fibrillation, the most common arrhythmia in the UK.


Want to know more?

Order or download our publications:

Heart rhythms booklet

Heart rhythms