Controlled electric shock to reset your heart's normal rhythm.

Cardioversion is a treatment for some types of cardiac arrhythmia (when your heart isn’t beating in its normal rhythm). It involves applying a controlled electric shock to your chest to reset your heart’s normal rhythm.

Why you might need it

You might need this treatment if you have an irregular heartbeat. The most common type of arrhythmia is called atrial fibrillation. This means the upper chambers in your heart are moving fast and aren’t contracting properly. The symptoms include dizziness, fainting, palpitations and a fluttering feeling in your chest.

One of the reasons that cardiac arrhythmias are treated is because some types of arrhythmia can sometimes lead to a stroke. This is because blood may start to pool in the chambers of your heart, where it can form a blood clot. If this clot moves through the bloodstream to the brain, it could cause a blockage of the blood supply and possibly cause a stroke.

We pride ourselves on our clinical excellence, you'll be looked after by an experienced multi-disciplinary care team.

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Who will do it?

Our patients are at the heart of what we do and we want you to be in control of your care. To us, that means you can choose the consultant you want to see, and when you want. They'll be with you every step of the way.

All of our consultants are of the highest calibre and benefit from working in our modern, well-equipped hospitals.

Our consultants have high standards to meet, often holding specialist NHS posts and delivering expertise in complex sub-specialty surgeries. Many of our consultants have international reputations for their research in their specialised field.

Before your treatment

You will have a formal consultation with a consultant. During this time you will be able to explain your medical history, symptoms and any concerns you might have.

Your consultant will discuss with you if they feel any further diagnostic tests, such as scans or blood tests, are needed. Any additional costs will be discussed before further tests are carried out. 

Before cardioversion, you will have an electrocardiogram (ECG). An ECG involves placing some electrodes (sticky pads) on your arms, legs and chest to measure the electrical impulses from your heart. Your cardiologist will use this to check whether your heartbeat has already returned to normal by itself or if you can be booked in for the procedure. An ECG is painless.

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Preparing for your treatment

We've tried to make your experience with us as easy and relaxed as possible.

For more information on visiting hours, our food, what to pack if you're staying with us, parking and all those other important practicalities, please visit our patient information pages.

Our dedicated team will also give you tailored advice to follow in the run up to your visit.


The procedure

We understand that going into hospital can potentially be a time of anxiety and worry. Our experienced and caring medical staff will be there for you, holding your hand, every step of the way.

Cardioversion is usually done under general anaesthesia, which means you will be asleep during the procedure. It typically takes up to 10 minutes.

During the procedure, your cardiologist will give you a controlled electric shock to your heart by placing paddles with soft gel pads on your chest. Small electrodes on your chest will monitor your heart’s rhythm throughout the procedure so your cardiologist can see whether or not the treatment is working.

Your cardiologist can tell immediately if the procedure has reset your heart to its normal rhythm. If it has not been successful, your cardiologist may repeat the treatment once or twice more.


Cardioversion is usually done as a day case, so you won't need to stay overnight in hospital. However if the procedure has not worked, you may need to stay in hospital overnight and have the procedure repeated the next day. Alternatively your cardiologist may arrange for you to come back at a later date for further treatment.

After this, you will be taken to your room or comfortable area where you can rest and recuperate until we feel you’re ready to go home.

Our nurses will closely monitor your heart beat and blood pressure. You will be able to go home once your consultant feels that you're ready, normally the same day.

Pain relief

After cardioversion, it's possible the skin on your chest may feel a little sore where the shock was administered – a bit like sunburn. We will provide you with any relevant pain relief.

Recovery time

If the cardioversion has worked, you will immediately feel better although you may have low blood pressure after the procedure. This usually only lasts a few hours and your nurse will monitor your blood pressure at regular intervals.

How your loved ones can help

Once you’re ready to be discharged from hospital, you’ll need to arrange a taxi, friend or family member to take you home as it's best not to drive.

Looking after you

Even after you’ve left hospital, we’re still looking after you every step of the way. After cardioversion, we will prescribe you with blood clot reduction (anticoagulant) medicine for you to continue taking at home. It's important you take it for as long as directed by your doctor.

Typically your consultant will want to see you after your treatment to see how you’re doing. You will usually be given a date for a follow-up appointment before you go home.

Your consultant will talk to you about the possible risks and complications of having this procedure and how they apply to you. Sometimes, cardioversion can trigger other arrhythmias (abnormal heart rhythms) or affect the way that your heart muscles work. It is also possible that a blood clot may be dislodged from your heart during the procedure. This could travel to the lungs or elsewhere in the body. If the blood clot causes a blockage in the brain, this could result in a stroke.

Your cardiologist will make sure that you are taking the most appropriate blood–thinning medicine to reduce this risk. If high energy shocks have been used, some parts of the heart tissue may die. This is called myocardial necrosis. Rarely, fluid may collect in your lungs after this cardioversion. This is called pulmonary oedema.

If you have any questions or concerns about your recovery, we're ready to help.

Why choose Spire?

We are committed to delivering excellent individual care and customer service across our network of hospitals, clinics and specialist care centres around the UK. Our dedicated and highly trained team aim to achieve consistently excellent results. For us it's more than just treating patients, it's about looking after people.

Important to note

The treatment described on this page may be adapted to meet your individual needs, so it's important to follow your healthcare professional's advice and raise any questions that you may have with them.

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