16952 Electrical Cardioversion

Overview

Electrical cardioversion is a short, planned procedure that uses a carefully controlled electric shock to reset your heart back into its normal rhythm. It is most often used for atrial fibrillation (AF) — a common condition where the heart beats fast and unevenly — or for other fast, irregular heart rhythms. You are given medicine that makes you sleepy and relaxed first, so you should not feel or remember the shock.

Yes. Electrical cardioversion is a common, well-established procedure used in hospitals around the world. It has been done safely for many decades and is one of the standard options for people with an irregular heartbeat.

It is mostly done in adults with atrial fibrillation or atrial flutter, and it becomes more common as people get older — especially over the age of 60. It is occasionally used in younger adults with other fast heart rhythms. It is rarely needed in children, and only in specialist heart care.

Symptoms

Common symptoms

• A fluttering, pounding or racing feeling in the chest (palpitations)
• Feeling unusually tired or lacking energy, even with normal sleep
• Shortness of breath, especially when walking, climbing stairs or exercising
• Feeling light-headed, dizzy or faint
• Mild chest discomfort or a 'tight' feeling
• Finding it harder to do your usual activities
• Swollen ankles or feet in some people
• No symptoms at all — the irregular rhythm is sometimes found by chance during a check-up

Symptoms in children

• Electrical cardioversion is rarely used in children; fast heart rhythms in children are usually managed by specialist children's heart teams
• If a child does have a fast or irregular heartbeat, signs can include poor feeding in babies, sweating, pale skin, rapid breathing, or being unusually sleepy
• Always speak to a doctor quickly if you are worried about a child's heartbeat or breathing

Symptoms in older adults

• Symptoms can be more subtle — such as growing tiredness, breathlessness on light activity, or feeling 'not quite right'
• Dizziness or falls may be the first sign of an irregular rhythm
• Confusion or new forgetfulness can sometimes be linked to a fast heart rhythm in older people
• Because other heart conditions are more common with age, assessment before cardioversion is especially thorough

Causes

Main causes

• Atrial fibrillation (AF) — a fast, uneven heartbeat starting in the upper chambers of the heart
• Atrial flutter — a related rhythm where the heart beats fast but in a more regular pattern
• Other fast heart rhythms that start above the lower chambers of the heart
• An irregular rhythm that has not responded to, or is not controlled by, heart rhythm medicines
• Sometimes used when your doctor wants to restore a normal rhythm more quickly and reliably

Risk factors

• Getting older
• High blood pressure
• Heart conditions such as valve problems, heart muscle weakness or previous heart attack
• An overactive thyroid gland
• Sleep apnoea (a condition where breathing pauses during sleep)
• Being overweight
• Drinking a lot of alcohol, or drinking heavily now and then
• Diabetes
• Some lung conditions or serious infections
• A family history of irregular heart rhythms
• Recent heart surgery or severe illness

When to see a doctor

See a doctor urgently if:

• Palpitations that do not settle, or that come with dizziness or breathlessness
• New shortness of breath at rest or with light activity
• Chest discomfort that comes and goes
• Feeling faint, or actually fainting
• New swelling in the legs or ankles
• After cardioversion: a racing or uneven heartbeat that returns, fever, or redness and pain where the pads were placed

Book a routine appointment if:

• You have been told your pulse is irregular at a health check
• You feel more tired or breathless than usual over weeks
• You want to discuss the pros and cons of cardioversion versus other options
• You have questions about your heart medicines or blood-thinning treatment
• You are planning travel or surgery and want advice about your heart rhythm

Diagnosis

Before cardioversion, your doctor needs to confirm exactly what your heart rhythm is doing, check how well your heart is working, and make sure the procedure is safe for you. This usually means a physical check-up, a tracing of your heartbeat, an ultrasound scan of the heart, and blood tests.

Tests that may be done

• Electrocardiogram (ECG) — painless sticky patches on your chest record the heart's electrical signals
• Ambulatory monitor (such as a Holter) — a small portable recorder you wear for a day or more to catch an irregular rhythm
• Echocardiogram — an ultrasound scan that shows the heart's shape, valves and pumping strength
• Blood tests — to check thyroid, kidney function, blood count and salts in the blood
• Chest X-ray — to look at the size of the heart and the lungs
• Transoesophageal echocardiogram (TOE) — a small camera passed gently down the throat to look closely at the heart's upper chambers and check for blood clots, if needed
• A check of your pulse and heart rate, plus blood pressure and weight

What to expect at your appointment

A heart specialist and a specialist nurse will usually see you in a clinic first. They will explain the procedure, check your medicines and ask about allergies, and answer questions. You will be asked not to eat or drink for several hours beforehand. On the day, a small tube (cannula) is placed in your arm, sticky pads are placed on your chest, and you are given sedation through the cannula. You will be monitored closely for a few hours afterwards before going home with someone.

Treatment

Electrical cardioversion is usually done in a hospital day unit or heart procedure room. You lie down, sticky pads are placed on your chest (sometimes also on your back), and you are given sedation so you are comfortable and drowsy. A brief, carefully timed electric shock is passed through the pads to reset the heart's rhythm — it usually lasts less than a second. Your heart rhythm, blood pressure and oxygen levels are watched throughout. If the first shock does not work, a further attempt may be made. You rest and are monitored for a few hours, and most people go home the same day.

Self-care at home

• Follow the fasting instructions exactly — usually no food or drink for several hours before the procedure
• Do not stop any of your regular medicines unless your doctor or pharmacist tells you to; ask specifically about blood-thinning medicines
• Arrange for a responsible adult to collect you and stay with you for 24 hours, as the sedation can make you drowsy
• Wear loose, comfortable clothing and leave jewellery at home
• Avoid driving, alcohol, operating machinery or making important decisions for at least 24 hours, or as long as you are advised
• Expect some mild redness or soreness where the pads were — keep the skin clean and mention any blistering or pain to your doctor
• Do not do heavy lifting or strenuous exercise for a few days; gentle walking is fine
• Check your pulse as you were shown, keep follow-up appointments, and go straight to emergency care if you feel very unwell

Medical treatments

Cardioversion is one part of a wider plan. Your doctor may also use medicines to slow the heart rate or to keep a steady rhythm, and often medicines that lower the chance of blood clots — these are especially important because an irregular rhythm raises the risk of stroke. If the rhythm goes back to being irregular, options include trying cardioversion again, adjusting medicines, or a specialist procedure called catheter ablation (where a thin tube is used to treat small areas inside the heart). All of this is planned with you, based on your symptoms and overall health.

When is surgery considered?

Electrical cardioversion itself is not surgery. If the irregular rhythm keeps returning after cardioversion, your heart team may discuss catheter ablation or, in some cases, a small implanted device. These are specialist decisions and your doctor will explain the risks and benefits in plain terms.

Living with this condition

After a successful cardioversion your heartbeat may feel steady and your energy may improve — but it is also common for the irregular rhythm to come back, sometimes weeks or months later. That does not mean anything went wrong. Keep checking your pulse, take your medicines as agreed, and keep your follow-up appointments so any change is picked up early.

Lifestyle tips

• Keep alcohol to a minimum — alcohol is one of the strongest triggers for atrial fibrillation
• If you smoke, stopping is one of the best things you can do for your heart
• Aim for a healthy weight, and lose weight gradually if you have been advised to
• Keep blood pressure and blood sugar well controlled
• Get help if you snore heavily or feel very sleepy in the day — sleep apnoea is treatable
• Take care with caffeine — it affects people differently
• Stay hydrated and avoid getting overly tired
• Ask your pharmacist before taking any new over-the-counter remedies, especially cold and flu products

Diet and exercise

A heart-friendly eating pattern — plenty of vegetables, fruit, nuts, beans, whole grains, oily fish and less salt and processed food — supports heart health and helps with weight and blood pressure. Regular moderate activity such as brisk walking, cycling or swimming is encouraged; build up gradually, and ask your doctor about a supervised cardiac rehabilitation programme if you have been less active. Your doctor or physiotherapist can advise on a safe starting point.

Mental health and emotional wellbeing

It is very normal to feel anxious about your heart rhythm, to worry before the procedure, or to feel low if symptoms come back. Uncertainty can be tiring, and some people find it affects sleep or mood. Talking to your heart team about your worries often helps — you are not being a nuisance. If low mood or anxiety is affecting your daily life, please tell your doctor, who can arrange support. If you ever feel you cannot cope or have thoughts of harming yourself, contact your local crisis line or go to your local emergency department straight away.

Prevention

You cannot always prevent an irregular heart rhythm, but you can lower the chance of it returning after cardioversion. Cutting back on alcohol, stopping smoking, keeping blood pressure and weight in a healthy range, treating sleep apnoea and staying active all help. Taking your medicines as agreed — including any blood-thinning medicine — is one of the most important ways to protect yourself.

Vaccines

People with heart conditions are usually advised to keep up to date with routine vaccinations, including flu and pneumonia vaccines, as infections can put extra strain on the heart. Ask your doctor, nurse or pharmacist which ones are right for you.

Screening programmes

There is no routine screening test for electrical cardioversion itself, but case-finding for atrial fibrillation is important. Checking your own pulse now and then, and having your blood pressure checked at health reviews, can help pick up an irregular rhythm early — especially if you are over 65 or have other heart risk factors.

Complications

If left untreated

• An ongoing irregular heartbeat raises the risk of a blood clot forming in the heart, which can travel to the brain and cause a stroke
• The heart may become weaker over time, leading to heart failure (where the heart struggles to pump as well as it should)
• Ongoing tiredness, breathlessness and reduced ability to exercise
• Sleep and mood can be affected by persistent symptoms

Long-term outlook

The outlook is generally good. Most people who have electrical cardioversion cope with it very well, and many feel better quite quickly afterwards. The procedure works well for a large share of people, though the rhythm can return — and if it does, there are still several effective options to try. Serious complications are uncommon, and your team will take steps to keep you safe. Many people with an irregular heartbeat live full, active lives with the right care and follow-up.

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