Your doctor will explain how to prepare for your cardioversion.
Preparing for an urgent cardioversion
If you need to have cardioversion urgently, your doctor will give you a medicine to stop your blood clotting, such as heparin. This is called an anticoagulant. You’re likely to receive this through a drip inserted into a vein in your hand or arm.
You may also have a scan called a transoesophageal echocardiogram to check for blood clots in your heart. To do this, a device called an ultrasound sensor is passed into your oesophagus to look at your heart. Your oesophagus is the pipe that goes from your mouth to your stomach. You’ll have the cardioversion as soon as your doctor has checked it’s safe to go ahead.
Preparing for a planned cardioversion
If your cardioversion is planned, there is plenty of time for you to take any medicines your doctor prescribes beforehand. They may prescribe:
- oral anticoagulant medicines – these help to stop your blood clotting (eg, warfarin)
- antiarrhythmic medicines – these help to control your heart’s rhythm, making it more likely that cardioversion will work
You may have some hospital tests before your cardioversion. These will help your doctor decide whether cardioversion is suitable for you. Tests you might have are explained below.
- Blood tests – for example, to check how well your blood clots.
- An electrocardiogram (ECG) – this measures the electrical activity in your heart and its rhythm.
- An echocardiogram – this is an ultrasound scan of your heart. It provides a clear image of your heart muscles and valves, and shows how well your heart is working.
- A transoesophageal echocardiogram – this is an ultrasound scan of your heart using a sensor put into your oesophagus (the pipe between your mouth and stomach).
Cardioversion is usually done as a day-case procedure, which means you’ll probably go home the same day. You may be asked to follow fasting instructions beforehand. This means not eating or drinking, typically for about four to six hours before your cardioversion. Follow your doctor’s advice about fasting.
Your doctor will explain what will happen before, during and after your procedure. This is your chance to understand what will happen. You may want to ask questions about the risks, benefits and any alternatives to the procedure. Noting questions down before your appointment can be helpful, as it might be hard to remember all your questions on the day.
Get all the information you need to decide whether to have cardioversion. If you choose to go ahead, it’s usual to be asked to sign a consent form.
When planning ahead for your procedure, remember you’ll need someone to take you home and stay with you afterwards because you’ve had a general anasesthetic.
There may be other treatments available to help regulate your heart’s rhythm. Which ones might be suitable for you will depend upon the type of arrhythmia you have and your general health. Some alternative treatments are listed below.
- Antiarrhythmic medicines – these are usually given as tablets and can help to control your heart’s rate and rhythm. They can work as well as cardioversion for treating most arrhythmias.
- Ablation – this is a procedure to stop any faulty electrical signals that your heart is making. It’s often done by placing a thin tube through one of your veins (often one in your groin) into your heart. The heart tissue that is causing the problem can then be treated via this tube.
- Having a pacemaker fitted – this is a device used to regulate your heart beat.
Your doctor will advise which treatment options are most suitable for you.
The thought of having an electric shock to your heart might be worrying, but the procedure is short and very safe.
Cardioversion usually takes about 10 minutes. Just beforehand, you’ll be given a sedative or a light general anaesthetic. Having a general anaesthetic will mean you’re asleep during the procedure, whereas a sedative will make you very drowsy. Once this has taken effect, your doctor will give your heart a brief, controlled electric shock. To do this, they will usually use two pads placed on your chest that come from a defibrillator device.
Your doctor will monitor your heart rate and rhythm during the procedure. This means they can immediately see whether the procedure has reset your heart to its normal rhythm. Your doctor may give you one or two more electric shocks to reset your heart if the first one doesn’t work fully.
When you wake up from your cardioversion, you may feel tired or unsteady. You’ll need to rest for a few hours until the effects of the anaesthetic or sedation have passed.
An ECG machine is used to keep an eye on your heart beat while you recover. Once you feel ready and the nurses looking after you are happy, you can get out of bed and walk around. You’ll be able to go home once your heart rhythm is stable and you feel ready to. Be sure to arrange for someone to drive you home and keep an eye on you that day.
You’ll probably be given a date for a follow-up appointment before you go home.
Your doctor will prescribe anticoagulant medicines for you to take at home. It’s important you keep taking anticoagulants for as long as your doctor recommends. This is to reduce your risk of getting a blood clot. Follow your doctors instructions and if you’re unsure about anything, ask.
You’ll need to arrange for someone to drive you home. General anaesthesia can make it harder to coordinate your movements and to think clearly. Therefore, it’s a good idea to have someone stay with you for the first 24 hours, in case you become unwell. Don’t drive, drink alcohol, operate machinery or sign legal documents during this time.
It’s a good idea to take it easy for a few days after your procedure. Your doctor will give you advice about when you can go back to work and begin exercise again. This timeframe differs from person to person.
Contact your GP if you notice any changes in your heart beat or your symptoms return. If your arrhythmia has come back after you have had cardioversion, you may need more treatment. See our frequently asked questions for more information about what to do if your arrhythmia returns.
Side-effects are the unwanted, but mostly temporary, effects you may get after having a procedure. For example, you may feel sick after the general anaesthetic. After having cardioversion, the skin on your chest may feel slightly sore, from where the shock was given to you.
Cardioversion can cause your blood pressure to temporarily drop, so you may have a headache or feel dizzy.
You might also find that the medicines you’re given to take before or after your cardioversion have side effects. Ask your doctor about any risks or side-effects of the particular medicines recommended for you.
Complications are problems that occur during or after a procedure.
The possible complications of cardioversion include the following.
- You may have an unexpected reaction to the anaesthetic or sedation. You’ll be given treatment to help if this happens, but it’s extremely rare.
- You may develop other problems with your heart rhythm during cardioversion. These are uncommon though and most don’t need treatment.
- There is a very small risk of having a stroke after cardioversion. A stroke happens when a blood clot which has formed in your heart is released during cardioversion. This then blocks the blood vessels in your heart or brain. You’ll be given anticoagulant medicines before and after your procedure to reduce this risk.
Anticoagulant medicines before cardioversion Why do I need anticoagulant medicines before having cardioversion?
Anticoagulant medicines help to reduce your risk of developing a blood clot. This is important, because having an irregular heart beat can increase your risk of getting a blood clot within your heart.
If you have an arrhythmia, it means you have an irregular heart beat. As a result, some of the blood in your heart might not be pushed out of your heart with each beat. The blood that remains may be more likely to clot. If a clot moves through your bloodstream to your brain, it could cause a stroke.
Your doctor will usually prescribe an anticoagulant medicine (such as warfarin) to help reduce your risk of developing a blood clot. You’ll usually be asked to take this for at least three or four weeks before and after having cardioversion.
If you have had urgent cardioversion, you’re likely to be given heparin through a vein in your hand or arm. This helps prevent any blood clots forming in your heart. You may have a scan too, to check for blood clots in your heart.
Cardioversion usually works well to correct arrhythmia, at least in the short-term. You might find that your arrhythmia returns in the future. If this happens, you may need to have cardioversion again or a different treatment.
Although cardioversion usually works, there is a chance your heart beat will not be corrected by the shock. The likelihood of cardioversion working varies from person to person and the type of arrhythmia you have.
Some people find that their arrhythmia returns again within a few days, weeks or months. Up to half of people treated with cardioversion for atrial fibrillation get the condition again within a year.
If your arrhythmia returns after your cardioversion, your doctor may recommend you have the procedure again, or they might recommend a different treatment. The best treatment for you may depend on how quickly your arrhythmia has come back.
Medicines after cardioversion Why do I need medicines to help regulate my heart rhythm after cardioversion?
Cardioversion helps to reset your heart’s rhythm when it goes wrong, but the problem can sometimes happen again. Medicines to help regulate your heart rate and rhythm are known as antiarrhythmic medicines. They are sometimes prescribed if cardioversion doesn’t work or if your arrhythmia might come back after treatment.
Your arrhythmia might return in the future, despite you having had cardioversion. Sometimes, an arrhythmia can return days, weeks, or months after you have cardioversion. Anti-arrhythmic medicines can help to prevent this happening. If you have atrial fibrillation, for example, you’re less likely to get arrhythmia again if you take an antiarrhythmic medicine after your cardioversion.
Examples of antiarrhythmic medicines are beta-blockers, amiodarone and verapamil. For some people, it may be possible to have a tablet to take only if you get symptoms. This means you wouldn’t need to take the medicine regularly.
Whether your doctor recommends an antiarrhythmic medicine for you, and which one they recommend, will depend on your symptoms and general health.
You’ll need to check with your doctor whether or not it’s safe for you to travel by air.
Many people with heart problems can still fly in an aeroplane. For example, if you have an arrhythmia but it’s being well controlled, you’ll probably still be able to fly. If you have recently had cardioversion or another hospital procedure, check with your doctor whether it’s safe for you to fly.
Things your doctor may take into account when advising whether it is safe for you to travel by air include:
- whether you have recovered fully from your procedure
- whether you still have an arrhythmia, and if so, what type
If you have ongoing heart problems and your doctor gives you the okay to travel, let your airline know about your condition. They can make sure any extra safety measures are in place that you might need. Also, check with your travel insurer that you will be covered.
Your doctor can also let you know about any extra precautions you should take. For example, long journeys can increase your risk of having a blood clot, so wearing compression stockings can reduce this risk.
- Defibrillation and cardioversion. Medscape. www.emedicine.medscape.com, published December 2014
- Synchronized electrical cardioversion. Medscape. www.emedicine.medscape.com, published October 2014
- Practical procedures. Oxford handbook of cardiology (online). Oxford Medicine Online. www.oxfordmedicine.com, published May 2012
- Defibrillation and cardioversion. PatientPlus. www.patient.info/patientplus, published February 2014
- Cardioversion and atrial fibrillation. AF Association. www.atrialfibrillation.org.uk, accessed July 2015
- Electrical cardioversion. Milan, Italy: SICS; 2014
- Cardioversion. British Heart Foundation. www.bhf.org.uk, accessed 22 July 2015
- Arrhythmias. Oxford handbook of cardiology (online). Oxford Medicine Online. www.oxfordmedicine.com, published May 2012
- Sucu M, Davutoglu V, Ozer O. Electrical cardioversion. Ann Saudi Med 2009; 29:201–06
- Heart rhythms. British Heart Foundation. www.bhf.org.uk, published May 2012
- European Heart Rhythm Association, European Association for Cardio-Thoracic Surgery, Camm AJ, et al. Guidelines for the management of atrial fibrillation. Euro Heart 2010; 31(19):2369–429. doi:10.1093/eurheartj/ehq278
- Atrial fibrillation: the management of atrial fibrillation. National Institute of Health and Care Excellence (NICE), August 2014. www.nice.org.uk
- General anaesthesia. PatientPlus. www.patient.info/patientplus, published June 2015
- Travel and your heart. British Heart Foundation. www.bhf.org.uk, published February 2015
- Fitness to fly for passengers with cardiovascular disease. British Cardiovascular Society. www.bcs.com, published July 2010.
We’d love to know what you think about what you’ve just been reading and looking at – we’ll use it to improve our information. If you’d like to give us some feedback, our short form below will take just a few minutes to complete. And if there's a question you want to ask that hasn't been answered here, please submit it to us. Although we can't respond to specific questions directly, we’ll aim to include the answer to it when we next review this topic.
Let us know what you think using our short feedback form Ask us a question
Reviewed by Alice Rossiter, Bupa Health Content Team, September 2015.
About our health information
At Bupa we produce a wealth of free health information for you and your family. We believe that trustworthy information is essential in helping you make better decisions about your health and care. Here are just a few of the ways in which our core editorial principles have been recognised.
Information StandardWe are certified by the Information Standard. This quality mark identifies reliable, trustworthy producers and sources of health information.
HONcodeThis site complies with the HONcode standard for trustworthy health information.
What our readers say about us
But don't just take our word for it; here's some feedback from our readers.
“Simple and easy to use website - not alarming, just helpful.”
“It’s informative but not too detailed. I like that it’s factual and realistic about the conditions and the procedures involved. It’s also easy to navigate to areas that you specifically want without having to read all the information.”
“Good information, easy to find, trustworthy.”
Our core principles
All our health content is produced in line with our core editorial principles – readable, reliable, relevant – which are represented by our diagram.
In a nutshell, our information is jargon-free, concise and accessible. We know our audience and we meet their health information needs, helping them to take the next step in their health and wellbeing journey.
We use the best quality and most up-to-date evidence to produce our information. Our process is transparent and validated by experts – both our users and medical specialists.
We know that our users want the right information at the right time, in the way that suits them. So we review our content at least every three years to keep it fresh. And we’re embracing new technology and social media so they can get it whenever and wherever they choose.
Here are just a few of the ways in which the quality of our information has been recognised.
The Information Standard certification scheme
You will see the Information Standard quality mark on our content. This is a certification programme, supported by NHS England, that was developed to ensure that public-facing health and care information is created to a set of best practice principles.
It uses only recognised evidence sources and presents the information in a clear and balanced way. The Information Standard quality mark is a quick and easy way for you to identify reliable and trustworthy producers and sources of information.
Certified by the Information Standard as a quality provider of health and social care information. Bupa shall hold responsibility for the accuracy of the information they publish and neither the Scheme Operator nor the Scheme Owner shall have any responsibility whatsoever for costs, losses or direct or indirect damages or costs arising from inaccuracy of information or omissions in information published on the website on behalf of Bupa.
Plain English Campaign
Our website is approved by the Plain English Campaign and carries their Crystal Mark for clear information. In 2010, we won the award for best website.
Website approved by Plain English Campaign.
British Medical Association (BMA) patient information awards
We have received a number of BMA awards for different assets over the years. Most recently, in 2013, we received a 'commended' award for our online shared decision making hub.
If you have any feedback on our health information, we would love to hear from you. Please contact us via email: email@example.com. Or you can write to us:
Health Content Team
15-19 Bloomsbury Way