Electrical cardioversion (DC cardioversion) (Direct current (DC) cardioversion)
A short procedure that uses a carefully timed electric shock, given while you are briefly asleep, to reset an abnormal heart rhythm back to normal.
✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review
In short
- Cardioversion uses a brief, timed electric shock — given while you are asleep — to reset an abnormal rhythm to normal.
- It restores normal rhythm quickly but does not cure the cause, so the abnormal rhythm can return and medicines or ablation may still be needed.
- Blood-thinning before and after is essential to lower the risk of a clot causing a stroke; sometimes a heart scan (TOE) is done first to check for clots.
- Because of the anaesthetic, you must not drive or do risky activities for 24 hours and need someone to take you home and stay with you.
A plain-English summary. The detail — including risks and recovery — is below.
At a glance
A general guide. Your specialist will give you advice for your situation.
Can restore a normal heart rhythm quickly, often in a single short procedure
People who have not had adequate blood-thinning and have not had a clot excluded by a TOE scan — the stroke risk is too high.
You wake in recovery while your rhythm and observations are checked. Mild grogginess and chest soreness are normal.
A clear blood-thinning plan stating how long to continue, based on your stroke risk.
You wake in recovery while your rhythm and observations are checked. Mild grogginess and chest soreness are normal.
Once you are fully awake, swallowing normally and stable, you can go home, usually by the afternoon, with someone...
Do not drive, operate machinery or anything risky (such as cooking on a hob), and have someone stay with you...
Sore chest skin under the pads settles; a soothing cream can help. Continue your blood-thinning and any rhythm...
What is electrical cardioversion (DC cardioversion)?
Electrical cardioversion, sometimes called DC cardioversion, is a treatment that uses a carefully timed electric shock to reset an abnormal heart rhythm — most often atrial fibrillation or atrial flutter — back to a normal rhythm.
Sticky pads are placed on your chest and connected to a defibrillator. Because the shock would be uncomfortable, you are given a short general anaesthetic or deep sedation so you are asleep for the moment it is delivered. The whole thing takes only a few seconds, and the shock is timed precisely to the heartbeat to be as safe as possible.
It is a way of restoring normal rhythm quickly. It does not change why the abnormal rhythm started, so the rhythm can come back, sometimes within days, weeks or months. Many people also need rhythm medicines or, later, an ablation to help the normal rhythm last.
A key safety point is blood-thinning. If the heart has been out of rhythm, a clot can form inside it; a shock could dislodge it and cause a stroke. So you usually need blood-thinning medicine for several weeks beforehand, or a scan of the heart (a TOE) to check for clots first.
Types, options & approaches
There may be different ways to do this. The right approach depends on the clinical question and your circumstances.
Electrical compared with chemical (drug) cardioversion
| Approach | How rhythm is reset | Notes |
|---|---|---|
| Electrical (DC) | A timed shock while you are asleep | Quick; needs an anaesthetic and blood-thinning |
| Chemical (drug) | Medicines given to restore rhythm | No shock, but slower and not always effective |
| Either approach | Resets rhythm only | Neither cures the cause; rhythm can return |
Which is chosen depends on your rhythm, how urgent it is and your heart. This is a guide, not advice — your cardiologist will explain what suits you.
Preparing for your procedure
- See the cardiologist or team arranging it; ask whether you need several weeks of blood-thinning first or a TOE scan to check for clots.
- Take your blood-thinning medicine exactly as prescribed beforehand — a missed dose can mean the procedure is cancelled for your safety.
- Bring a full list of your medicines; you will be told which to take on the day and which to adjust.
- You will be asked not to eat or drink for a few hours beforehand because of the anaesthetic.
- Arrange for someone to take you home and stay with you overnight, as you cannot drive after the anaesthetic.
- Wear or bring loose clothing; the chest needs to be accessible for the pads.
- Tell the team about any chest skin problems or allergies to dressings.
What happens
On the day, the team checks your rhythm and confirms your blood-thinning has been taken as instructed. Sticky pads are placed on the front and back, or both sides, of your chest, and you are connected to monitors.
You are given a short general anaesthetic or deep sedation, so you are asleep and feel nothing. The defibrillator then delivers a brief, precisely timed shock through the pads. Sometimes more than one shock, at a higher setting, is needed. The shock itself lasts only moments.
You wake up shortly afterwards in a recovery area, where your rhythm and observations are checked. Most people can go home the same day, once they are fully awake, able to swallow normally and the team is happy. You may have some chest soreness, and the skin under the pads can look red, like mild sunburn.
Is this procedure right for me?
A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.
May not be suitable if…
- People who have not had adequate blood-thinning and have not had a clot excluded by a TOE scan — the stroke risk is too high.
- Those with an untreated reversible cause (such as an overactive thyroid) where treating it first may restore rhythm or improve success.
- People in whom the abnormal rhythm is long-standing and very likely to return immediately, where the benefit may be limited.
- Anyone in whom a short anaesthetic is unsafe until other problems are addressed.
Delay or rearrange if…
- Blood-thinning has not been taken exactly as prescribed, or a clot has not been excluded.
- Active infection or another acute illness that should be treated first.
- Low or high potassium or other blood disturbances that should be corrected.
- An untreated overactive thyroid or other reversible driver of the rhythm.
Alternatives to discuss
- Chemical (drug) cardioversion using medicines instead of a shock.
- Rate-control medicines to slow the heart while accepting the abnormal rhythm, with blood-thinning.
- Catheter ablation for longer-term rhythm control.
- Treating an underlying cause first, which can sometimes restore normal rhythm.
Before you decide
Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.
What matters most to me?
Think about symptoms, daily life, work, caring responsibilities, sport, fertility, travel, appearance and anxiety — the right choice depends on your priorities, not just the medical facts.
What are all my options?
Ask about waiting, monitoring, medicines, rehabilitation, a smaller or larger procedure, a different test, NHS referral, or a second opinion where that would help.
What would make me pause?
Active infection, pregnancy, unstable medical problems, smoking, medicines that increase bleeding, poor support at home, or feeling pressured are all reasons to slow down and get tailored advice.
What happens if I do nothing today?
For some problems, waiting is safe; for others, delay can make treatment harder. A good consultation should explain the trade-off in plain English.
Comfort, sedation or contrast choices
If local anaesthetic, sedation, contrast or pain relief is used, ask what is planned, why, and what it means afterwards.
Benefits
- Can restore a normal heart rhythm quickly, often in a single short procedure
- May ease symptoms such as palpitations, breathlessness and tiredness when normal rhythm returns
- Lets the team see whether you feel better in a normal rhythm, which can guide longer-term treatment
- Avoids a longer procedure; you are usually home the same day
- Can be combined with medicines or ablation to help the normal rhythm last
Risks & complications
- Red, sore skin where the pads were placed, like mild sunburn, for a few days
- Chest tenderness or aching afterwards
- Drowsiness or feeling groggy from the anaesthetic for the rest of the day
- The shock not restoring a normal rhythm, or the rhythm returning soon afterwards
- Needing more than one shock at a higher setting
- A temporary dip in blood pressure or a slow heartbeat after the shock
- The usual small risks of a short anaesthetic
- A stroke from a clot being dislodged — the reason blood-thinning and clot checks matter
- A more serious heart-rhythm disturbance triggered by the shock
- A skin burn from the pads
- A serious reaction to the anaesthetic
The most important risk to understand is stroke: if the heart has been out of rhythm, a clot can form and a shock could dislodge it. This is why blood-thinning for several weeks beforehand, or a TOE scan to check for clots, is essential, and why blood-thinning usually continues afterwards. Never skip your blood-thinner before a cardioversion. Ask your cardiologist how long you must stay on it after the procedure.
Published figures to discuss
Complications are uncommon when anticoagulation and clot-risk checks are handled properly, but the consequences of a clot-related event can be serious. Published risks vary with atrial-fibrillation duration, anticoagulation status, heart disease and the anaesthetic/sedation used.
| Figure | Reported range | How to interpret it | Source / confidence |
|---|---|---|---|
| Skin redness, soreness or minor burn | Uncommon with modern biphasic cardioversion, usually mild | Pad position and good skin contact reduce the risk. | Cardioversion thromboembolism review — PMCpmc.ncbi.nlm.nih.govSource-linked context |
| Rhythm returning soon after cardioversion | Common enough to discuss; recurrence is much more likely without rhythm-control planning | Cardioversion restores rhythm but does not cure the tendency to AF or flutter. | Guide sourcesClinical context |
| Stroke or embolism | Rare when anticoagulation guidance is followed; higher if clot risk is not managed | This is why blood thinners or a TOE scan may be needed before cardioversion. | Cardioversion thromboembolism review — PMCpmc.ncbi.nlm.nih.govSource-linked context |
| Slow heartbeat, low blood pressure or another rhythm problem | Uncommon, usually detected immediately under monitoring | The team can treat this at the time; people with conduction disease may have higher risk. | Cardioversion thromboembolism review — PMCpmc.ncbi.nlm.nih.govSource-linked context |
These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.
What happens afterwards
Recovery is quick — most people are home the same day. The main limits come from the anaesthetic, which means no driving or risky activities for 24 hours, rather than from the shock itself.
- Red, sore skin where the pads were, easing over a few days
- Mild chest tenderness afterwards
- Grogginess from the anaesthetic for the rest of the day
- Knowing on the day whether normal rhythm was restored, even if it later returns
Aftercare
- Keep taking your blood-thinning medicine exactly as prescribed — do not stop without your cardiologist's advice.
- Do not drive or do anything risky for 24 hours after the anaesthetic, and have someone stay with you.
- Soothe sore chest skin with a non-perfumed moisturiser or after-sun cream, or any cream you are given.
- Take any rhythm medicines as directed.
- Rest for the day and return to normal activities the next day if you feel well.
- Attend your follow-up so the rhythm can be checked.
- Know the warning signs of a stroke and act on them straight away.
- Blood-thinning medicine taken exactly as instructed before the day
- Nothing to eat or drink for the time you were told beforehand
- Someone to take you home and stay with you overnight
- No driving or risky activities planned for 24 hours
- A soothing cream ready for sore chest skin
- A follow-up appointment to check the rhythm
- The clinic's contact number saved for concerns
Scars and how they heal
There is no cut and no scar. The skin under the pads can be red and sore, like mild sunburn, for a few days, and a soothing cream usually helps it settle.
⚠ Get urgent help if…
- Signs of a stroke: face drooping, arm weakness or slurred speech — call 999 immediately
- Sudden severe chest pain or breathlessness — call 999
- Fainting, collapse or a fast pounding heartbeat that does not settle
- A return of the palpitations or symptoms you had before — contact your team
- Blistering or a worsening burn where the pads were
- Difficulty breathing or swelling of the face or lips (possible reaction) — call 999
Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.
General guidance — it doesn't replace the specific advice your specialist gives you.
Results & realistic expectations
A good result means the shock restores a normal rhythm, often immediately, and you may feel better straight away. The team can see on the monitor whether it has worked before you go home.
Cardioversion resets the rhythm but does not change why it went out of rhythm in the first place, so normal rhythm does not always last — it can return within days, weeks or months. That is not a failure of the procedure so much as the nature of the condition. Many people need rhythm medicines, a repeat cardioversion, or an ablation to help the normal rhythm hold. Blood-thinning decisions afterwards are based on your individual stroke risk, not just on whether the rhythm stayed normal.
How long the normal rhythm lasts varies a lot. For some people it holds for a long time; for others the abnormal rhythm returns quite soon, especially if the underlying causes (such as high blood pressure, a leaky valve or an overactive thyroid) are not addressed. Rhythm medicines can improve the chance it lasts, and ablation is an option if cardioversion alone does not give durable control.
Related tests, treatments or support
Cardioversion is often part of a wider plan. Rhythm medicines may be started before or after to help the normal rhythm last, and a TOE scan may be done first to check for clots. Some people have a cardioversion before or after an ablation. Treating contributing factors, such as an overactive thyroid or high blood pressure, improves the chance of success.
Follow-up & long-term care
You will usually be reviewed to check whether the normal rhythm has lasted and to adjust medicines, sometimes with rhythm monitoring. Blood-thinning is reviewed based on your stroke risk. If the rhythm returns, your team will discuss medicines, a repeat cardioversion or ablation.
- Continue blood-thinning until your team advises otherwise, based on your stroke risk
- Take any rhythm medicines as directed to help the normal rhythm last
- Manage contributing factors such as blood pressure, weight, alcohol and thyroid problems
- Report a return of palpitations or symptoms rather than waiting
- Be ready to discuss a repeat cardioversion or ablation if the rhythm comes back
Repeat, follow-on and what comes next
- The abnormal rhythm often returns over time, so a repeat cardioversion is sometimes needed.
- If the rhythm keeps returning, the plan usually shifts towards rhythm medicines or an ablation.
- Each cardioversion still needs proper blood-thinning or a clot check beforehand.
- Treating underlying causes improves the chance the normal rhythm lasts after a repeat.
Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.
What good aftercare looks like
- A clear blood-thinning plan stating how long to continue, based on your stroke risk.
- Written advice on the 24-hour anaesthetic restrictions and someone to stay with you.
- A follow-up to check whether the rhythm has lasted, with rhythm monitoring if needed.
- A named contact and clear stroke warning signs to act on.
- A plan for what to do, including medicines or ablation, if the rhythm returns.
What affects the cost
Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:
- The cardiologist's fee and the facility fee
- The anaesthetist's fee for the short anaesthetic or sedation
- Whether a TOE scan to check for clots is needed first
- Any rhythm medicines started around the procedure
- Follow-up appointments and rhythm monitoring
- The chance of needing a repeat cardioversion if the rhythm returns
- The cardiologist's fee and the facility fee
- The anaesthetist's fee for the anaesthetic or sedation
- Whether a TOE scan is included if needed
- Follow-up appointments to check the rhythm
- The policy and cost if a repeat cardioversion is needed
- The cancellation policy (including if blood-thinning has not been taken correctly)
- What happens, and what it costs, if a complication occurs
On the NHS? Electrical cardioversion is widely provided by the NHS when clinically indicated; private care is usually chosen for speed or choice of cardiologist.
You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.
Consent traps and marketing red flags
These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.
Consent traps
- Not explaining clearly that the normal rhythm can return and the procedure may need repeating.
- Underplaying the stroke risk and the absolute need for blood-thinning or a clot check.
- Not making clear that you must not drive or do risky activities for 24 hours after the anaesthetic.
- Not discussing whether medicines or ablation would give more durable control.
- Failing to review how long blood-thinning should continue afterwards.
Marketing red flags
- Presenting cardioversion as a 'cure' for atrial fibrillation.
- Downplaying the need for blood-thinning before and after.
- Not mentioning that the rhythm commonly returns.
- Implying it is a trivial treatment with no anaesthetic considerations.
Choosing a specialist safely
- Check the specialist is on the GMC Specialist Register for this area.
- Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
- You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
- Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
- You're entitled to your total cost in writing — including any follow-up — before you decide.
Questions to ask your medical professional
Take this to your consultation. A good specialist will welcome every one of these.
- Do I need several weeks of blood-thinning first, or a TOE scan to check for clots?
- How long must I stay on blood-thinning after the procedure?
- How likely is my normal rhythm to last, and what happens if it returns?
- Would rhythm medicines or an ablation help the result last?
- Are there underlying causes (like thyroid or blood pressure) we should treat first?
- What should I do if I notice stroke symptoms or my palpitations come back?
- Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
- Will you be the specialist who carries out my procedure, and who looks after me afterwards?
- What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
- What does a realistic result look like — and what can this procedure not achieve?
- What are my options, including waiting, doing nothing for now, or choosing a different approach?
- Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
- What is the total cost in writing, including any follow-ups, and how much time do I have to decide?
Frequently asked questions
Will the shock hurt?
Why do I need blood thinners before and after?
Will my normal rhythm stay?
When can I drive again?
How long will I be in hospital?
Can I have cardioversion on the NHS?
Find a verified specialist for electrical cardioversion (dc cardioversion)
Every consultant is GMC-checked and independently reviewed. Search by postcode and distance, or switch to a map. Ordered by rating, relevance and recency — never by who pays.
No verified consultants list this procedure yet — browse the full directory.
How we made this page
Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →
Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.
Sources & standards: British Heart Foundation — Cardioversion Royal Brompton & Harefield (NHS) — Cardioversion Cambridge University Hospitals NHS — Cardioversion: general advice DVLA — Cardiovascular disorders: assessing fitness to drive Cardioversion thromboembolism review — PMC American Heart Association — Cardioversion DVLA — Assessing fitness to drive (medical guidance) DVA Northern Ireland — Tell DVA about a driver medical condition
Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.
Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.
Related guides: Catheter ablation for arrhythmia · Cardiac resynchronisation therapy (CRT / biventricular pacemaker) · Balloon valvuloplasty · Coronary angiogram (cardiac catheterisation) · Coronary angioplasty and stenting (PCI)