Draining fluid from around the heart (pericardiocentesis)
A procedure that uses a fine needle and tube to drain fluid that has built up in the sac around the heart, to relieve pressure on the heart and to help find the cause.
✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review
In short
- Pericardial aspiration drains fluid from the sac around the heart, relieving pressure that can stop the heart pumping properly.
- It is both a treatment (which can be life-saving in tamponade) and a test, as the fluid is sent to find the cause.
- It treats the fluid, not always the underlying cause, so the cause still needs investigating and managing, and fluid can come back.
- It is usually done with ultrasound or X-ray guidance, but it still carries real risks such as damage to the heart, bleeding and rhythm problems.
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.
Relieves pressure on the heart, which can be life-saving in cardiac tamponade
The fluid collection is small, well away from the needle path, or loculated, where surgical drainage may be safer.
You are monitored closely for blood pressure, heart rhythm and any return of fluid. An echocardiogram usually checks how much fluid is left.
Close monitoring after the procedure, with a repeat echocardiogram to check the fluid has not returned.
You are monitored closely for blood pressure, heart rhythm and any return of fluid. An echocardiogram usually...
The remaining fluid drains gradually and the amount is measured. You stay in hospital and the drain is removed...
Once the fluid has settled and you are stable, the drain comes out and many people go home, with a plan to treat...
The needle site heals quickly. Watch for breathlessness, chest pain, fever or a fast heartbeat, which could mean...
What is pericardial aspiration (pericardiocentesis)?
The heart sits inside a thin, two-layered sac called the pericardium. Normally there is only a tiny amount of fluid between the layers. If too much fluid builds up (a pericardial effusion), it can press on the heart and stop it filling and pumping properly — a dangerous situation called cardiac tamponade, which can be life-threatening.
Pericardial aspiration (pericardiocentesis) drains this fluid using a fine needle passed through the skin below or beside the breastbone, guided by ultrasound (an echocardiogram) or X-ray. A soft tube (drain) is often left in place for a short time to let the rest of the fluid drain off. Removing the fluid relieves the pressure, so the heart can work normally again.
It is both a treatment and a test: relieving the pressure can be life-saving, and the fluid is usually sent to the laboratory to help find the cause, which can range from infection or inflammation to a reaction after heart surgery, kidney problems or cancer.
It is less invasive than open drainage, but it is still a procedure on the heart with real risks, including damage to the heart or a nearby structure, bleeding and an abnormal heart rhythm. It treats the fluid, not always the underlying cause, so the cause still needs investigating and managing.
Types, options & approaches
There may be different ways to do this. The right approach depends on the clinical question and your circumstances.
Needle drainage vs surgical drainage (pericardial window)
| Point | Needle drainage | Surgical window |
|---|---|---|
| Approach | Needle and soft tube through the skin | Small operation to open the sac |
| Anaesthetic | Usually local, sometimes sedation | Usually general anaesthetic |
| Best for | Rapid relief, sampling the fluid | Fluid that keeps coming back |
| Recovery | Usually little physical recovery | Longer, as it is an operation |
| Sample of the sac lining | Not usually possible | A piece of the sac can be taken if needed |
Needle drainage is often the first step, especially in an emergency. A surgical window may be considered if fluid keeps returning or a sample of the sac lining is needed. Your team will explain which suits your situation.
Preparing for your procedure
- In an emergency, there may be little time to prepare — relieving the pressure on the heart comes first.
- When planned, expect an echocardiogram to confirm the fluid and find the safest place to drain it.
- Tell the team about all your medicines and supplements, especially blood thinners, which often need pausing or reversing.
- Expect blood tests, including clotting, and an ECG before the procedure.
- You may be asked not to eat or drink for a few hours if sedation is planned.
- Ask whether a drain will be left in, and roughly how long you may stay in hospital.
- Understand that the fluid will usually be sent to the laboratory to look for the cause.
What happens
The procedure is usually done in a monitored area, such as a coronary care unit or catheter lab, by a cardiologist and team. You lie propped up, your heart rhythm and blood pressure are monitored, and the skin below or beside the breastbone is numbed with local anaesthetic; you may also have light sedation.
Using ultrasound (an echocardiogram) or X-ray to guide the needle safely, the doctor passes a fine needle through the numbed skin into the fluid around the heart and draws some off. A guidewire is often used to place a soft drainage tube, which may be left in for a day or two so the rest of the fluid can drain gradually. As the fluid comes off, the pressure on the heart is relieved, and people in tamponade often feel better quickly.
The procedure often takes around 30 to 60 minutes. Afterwards you are monitored closely, and an echocardiogram usually checks how much fluid is left and whether it is building up again. The fluid is sent to the laboratory to help find the cause.
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…
- The fluid collection is small, well away from the needle path, or loculated, where surgical drainage may be safer.
- A bleeding (haemorrhagic) effusion or a tear of the aorta or heart, where surgery is usually needed instead.
- Uncorrected severe clotting problems, unless the procedure is needed as a life-saving emergency.
- Fluid that keeps coming back, where a surgical pericardial window may be the better option.
Delay or rearrange if…
- The situation is not an emergency and blood thinners or clotting problems can be safely corrected first.
- Imaging has not yet confirmed the fluid and the safest place to drain it.
- Important blood tests, including clotting, are missing.
- A surgical approach is being considered because the fluid is hard to reach or keeps returning.
- Sedation is planned and you have recently eaten or drunk, unless it is an emergency.
Alternatives to discuss
- Close monitoring with repeat echocardiograms if the effusion is small and not pressing on the heart.
- Treating the underlying cause (for example anti-inflammatory medicine or treating an infection) where the heart is not under pressure.
- Surgical drainage (a pericardial window), especially for fluid that keeps coming back.
- Taking a sample of the sac lining at surgery if the cause is unclear.
- Urgent surgery if the cause is bleeding or a tear, rather than needle drainage.
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
- Relieves pressure on the heart, which can be life-saving in cardiac tamponade
- Often improves breathlessness and low blood pressure quickly as the fluid comes off
- Provides a fluid sample to help find the cause, guiding further treatment
- Less invasive than open surgical drainage
- Can usually be done with local anaesthetic rather than a general anaesthetic
- A drain can be left in to remove fluid gradually and measure how much returns
Risks & complications
- Discomfort or a sharp feeling as the local anaesthetic and needle go in
- Bruising or a little bleeding at the needle site
- A brief drop in blood pressure or a slow pulse during the procedure
- Some chest discomfort while the drain is in place
- An abnormal heart rhythm during the procedure, usually short-lived
- Air getting into the space around the lung (pneumothorax)
- The drain blocking or coming out and needing to be repositioned
- Fluid building up again, sometimes needing repeat drainage
- Damage to the heart muscle, a heart chamber or a coronary artery, occasionally needing surgery
- Significant bleeding into the sac, which can itself cause tamponade
- Injury to a nearby organ such as the lung, liver or stomach
- A serious heart-rhythm problem or, very rarely, death
The most serious specific risks are damage to the heart or a coronary artery and significant bleeding, which is why ultrasound or X-ray guidance, monitoring and an experienced operator matter. Blood thinners increase bleeding risk and usually need managing first. Ask the team how the needle will be guided, what the likely cause of your fluid is, and what the plan is if the fluid comes back.
Published figures to discuss
Risk depends on how the fluid is collected, the operator's experience, the use of imaging guidance, and how urgent and unwell the situation is. Modern image-guided drainage by experienced cardiologists has a low complication rate. The ranges below come from published series; emergency drainage in a very unwell person carries higher risk, and the fluid can return depending on the cause.
| Figure | Reported range | How to interpret it | Source / confidence |
|---|---|---|---|
| Major complications overall | About 0.3–3.9% in large image-guided observational series | Includes serious bleeding, heart or vessel injury, serious rhythm problems and pneumothorax needing a drain; image guidance lowers risk. | Pericardiocentesis — StatPearls (NCBI)ncbi.nlm.nih.govPublished figure |
| Minor complications | About 0.4–20% across published series | Includes a brief drop in blood pressure, slow pulse, minor arrhythmias and small air leaks around the lung. | Pericardiocentesis — StatPearls (NCBI)ncbi.nlm.nih.govPublished figure |
| Fluid building up again | No single dependable figure; recurrence is mainly cause-driven | Cancer, ongoing inflammation and incomplete drainage are more likely to recur; repeated drainage or a surgical window may be needed. | Pericardiocentesis — StatPearls (NCBI)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
The drainage itself usually needs little physical recovery, but how you feel afterwards depends mostly on the underlying cause and on how long the drain stays in. Many people feel much better once the pressure on the heart is relieved.
- Quick relief of breathlessness once the pressure on the heart is eased
- Mild soreness or bruising at the needle site
- Some chest discomfort while the drain is in place
- Tiredness, particularly if you were unwell beforehand
- Waiting a few days for the fluid test results
Aftercare
- Take all medicines as prescribed, and check with your team before restarting any blood thinners.
- Keep the needle/drain site clean and dry and watch for redness, swelling or discharge.
- Rest as needed and build activity back up as the underlying cause is treated.
- Attend follow-up appointments, including any repeat echocardiogram to check the fluid.
- Make sure you understand the likely cause and the plan to treat it.
- Seek urgent help if breathlessness, chest pain, fever or a fast heartbeat returns.
- Keep any appointments for further tests on the cause of the fluid.
- A clear explanation of the likely cause and the plan to treat it
- Knowledge of when to restart any paused blood thinners
- A follow-up echocardiogram or clinic appointment noted
- How to look after the needle/drain site and what to watch for
- Someone to help at home if you were unwell beforehand
- Clinic and out-of-hours contact numbers saved
Scars and how they heal
There is no surgical incision. You will usually have only a small puncture mark where the needle and drain entered the skin below or beside the breastbone, which may bruise and fades over a couple of weeks.
⚠ Get urgent help if…
- Sudden or worsening breathlessness, especially lying flat
- Chest pain or tightness that does not settle
- Fainting, dizziness or a very fast or irregular heartbeat
- Fever, chills or feeling generally unwell, which can signal infection
- Increasing redness, swelling, pain or discharge at the needle/drain site
- Coughing up blood or new severe pain, which needs urgent assessment
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 successful pericardial aspiration removes enough fluid to relieve the pressure on the heart, so it can fill and pump normally again. In cardiac tamponade this can be life-saving, and many people feel much better quickly. The fluid sent to the laboratory often helps identify the cause, which guides the next steps in treatment.
Draining the fluid treats the build-up but not always the underlying cause, so the cause still needs investigating and managing, and the fluid can return. Sometimes the tests do not give a clear answer, and further investigation or repeat drainage is needed. Your team should explain what the fluid showed and what happens next.
How durable the result is depends almost entirely on the cause. If the cause is a one-off — such as a single episode of inflammation — the fluid may not return after drainage. If the cause is ongoing, such as some cancers, kidney problems or recurrent inflammation, fluid can build up again and may need repeat drainage or a surgical window. This is why finding and treating the cause, and having follow-up scans, matters as much as the drainage itself.
Related tests, treatments or support
Pericardial aspiration is sometimes done alongside other tests to find the cause, such as blood tests, scans or, occasionally, taking a sample of the sac lining during surgery. It may also be needed as an urgent step if fluid builds up as a complication of another heart procedure. Treating the underlying cause — for example with anti-inflammatory medicines, treating an infection, or cancer treatment — is a separate and important part of care.
Follow-up & long-term care
You will be monitored closely after the procedure and usually have a repeat echocardiogram to confirm the fluid has not built up again before and after the drain is removed. Longer-term follow-up focuses on the fluid test results and on finding and treating the underlying cause, often shared between your cardiologist and other specialists. Tell your team promptly if breathlessness, chest pain or a fast heartbeat returns.
- Follow-up echocardiograms to check the fluid has not returned
- Investigating and treating the underlying cause of the fluid
- Taking any prescribed medicines, such as anti-inflammatories or treatment for the cause
- Prompt review if breathlessness, chest pain or a fast heartbeat returns
- Care of the needle/drain site until it has healed
Repeat, follow-on and what comes next
- Fluid can build up again, especially with ongoing causes, and may need repeat drainage.
- A surgical pericardial window may be needed if the fluid keeps returning.
- Sometimes the fluid tests do not give a clear cause and further investigation is needed.
- Treating the underlying cause is essential to reduce the chance of the fluid coming back.
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
- Close monitoring after the procedure, with a repeat echocardiogram to check the fluid has not returned.
- A clear plan to investigate and treat the underlying cause, shared between the relevant specialists.
- A named contact and clear out-of-hours route for breathlessness, chest pain, fever or a fast heartbeat.
- Clear advice on the needle/drain site and on when to restart any paused blood thinners.
- Follow-up to review the fluid test results and arrange any further investigation.
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 and team's fees, and whether it is done urgently or as a planned procedure
- Whether ultrasound or X-ray (catheter-lab) guidance is used
- Whether sedation is used, and whether a drain is left in
- Length of hospital stay and level of monitoring needed
- Laboratory tests on the fluid to find the cause
- Investigation and treatment of the underlying cause
- Follow-up appointments and repeat echocardiograms
- The cardiologist's and team's fees
- Imaging and monitoring charges (ultrasound or catheter lab)
- Whether a drain and laboratory fluid tests are included
- Expected length of stay and the cost of extra days
- Investigation and treatment of the underlying cause
- Follow-up appointments and repeat echocardiograms
- What happens, and who pays, if the fluid returns, a complication occurs or surgery is needed
On the NHS? Pericardial aspiration is provided on the NHS, often urgently or as an emergency when fluid is pressing on the heart; private care follows the same clinical principles, and urgent cases are treated wherever you are.
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
- Treating the drainage as a cure without explaining that the underlying cause still needs managing.
- Not explaining that the fluid can come back and may need repeat drainage or surgery.
- Blood thinners and clotting problems not reviewed before a non-emergency procedure.
- The serious risks of heart or vessel injury and bleeding not spelled out.
- No clear plan for who to contact and what to watch for if symptoms return after discharge.
Marketing red flags
- Describing it as a simple or without risks tap, without mentioning heart injury, bleeding or rhythm problems.
- Implying drainage alone cures the problem, without addressing the cause.
- Offering it without proper imaging guidance and monitoring.
- Not explaining when surgical drainage would be safer.
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.
- How will the needle be guided, and how will my heart be monitored?
- What do you think is causing the fluid, and how will you confirm it?
- Will a drain be left in, and roughly how long might I stay in hospital?
- What is the plan if the fluid builds up again?
- Do any of my medicines, especially blood thinners, need stopping first?
- When will I know the fluid test results, and what happens next?
- 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
Is draining fluid from around the heart dangerous?
Will I be awake during it?
Why is the fluid sent to the laboratory?
Can the fluid come back?
How long will I be in hospital?
Is this done on the NHS?
Find a verified specialist for draining fluid from around the heart (pericardiocentesis)
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: Pericardiocentesis — StatPearls (NCBI) ESC — Pericardiocentesis in cardiac tamponade: indications and practical aspects Cardiac tamponade — StatPearls (NCBI) Perioperative implications of pericardial effusions and cardiac tamponade — PMC NHS — Pericarditis (inflammation and fluid around the heart) ESC 2015 Guidelines — diagnosis and management of pericardial diseases (European Heart Journal, 2015)
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: Pericardial window / drainage · Echocardiogram (heart ultrasound) · CT scan · Balloon valvuloplasty · Cardiac resynchronisation therapy (CRT / biventricular pacemaker)