Pericardial effusion: causes, symptoms and treatment

The UK patient information that describes pericardial effusion places it mostly in the setting of pericarditis, which is inflammation of the pericardium. The NHS describes the pericardium as a protective fluid-filled sac around the heart, and says that in pericarditis blood or fluid can leak into it.

The British Heart Foundation says pericarditis is most commonly caused by a virus, such as flu or Covid-19, or another infection, or by inflammatory conditions such as rheumatoid arthritis. More rarely it can follow injury to the chest, for example after a car accident, heart surgery or a heart attack, or be caused by another health problem such as cancer, kidney failure or an underactive thyroid, or by certain medicines or vaccines. Sometimes it is not possible to know the cause, which is called idiopathic pericarditis.

The same sources describe the effusion as one of the complications of that inflammation rather than a separate disease. Dudley notes that fluid removed by pericardiocentesis can be sent for analysis to identify the cause of the effusion, which is one reason a larger effusion may be drained even when it is not causing an emergency.

The sources I could read do not give percentages for how often each cause occurs, so those are not quoted here.

The heart sits inside a thin, double-layered sac called the pericardium. There is normally a small amount of lubricating fluid between the layers. An effusion means there is more fluid than usual in that space. Dudley uses the plain phrase excess fluid for pericardial effusion.

Size and speed matter more than the label. Worcestershire says a small amount of fluid is no problem and usually goes when the inflammation settles, while a lot of fluid can press on the heart. When the pressure from fluid restricts the heart's ability to beat effectively, Dudley calls this cardiac tamponade.

A small effusion may not be noticed at all, and Worcestershire says a small amount of fluid is no problem. When the fluid is part of pericarditis, the main symptom is chest pain. The NHS says the pain usually feels sharp or stabbing, spreads to the shoulders, arms or tummy, gets worse when you breathe in deeply, swallow, cough or lie down (especially on your left side) and gets better when you lean forward. You may also have a high temperature, a cough or painful joints.

When a lot of fluid builds up, Worcestershire says symptoms include shortness of breath which gets worse and worse. The BHF lists shortness of breath, feeling light-headed and feeling sick among the other pericarditis symptoms. The pattern to take seriously is breathing that is steadily worsening, particularly after a recent chest infection or inflammation of the heart lining.

The NHS says a GP will listen to your heart, because pericarditis can change the sound it makes, and to confirm it may do blood tests or refer you for a chest X-ray, an ECG or an echocardiogram in hospital. The BHF adds that you may also have a cardiac MRI or CT scan.

The echocardiogram is the test that shows fluid around the heart. The NHS describes it as an ultrasound scan of the heart, usually done in hospital by a sonographer, with sticky patches on the chest, gel and a probe moved over the chest. The most common type is a transthoracic echocardiogram and the scan takes around 30 to 40 minutes.

Treatment depends on the cause. For pericarditis, the NHS says you may be given anti-inflammatory painkillers such as ibuprofen, and that a GP may prescribe colchicine if painkillers do not work or pericarditis keeps coming back, steroids if colchicine does not work and antibiotics if a bacterial infection is the cause. Worcestershire says usually pericarditis can be treated without admission to hospital, and that colchicine is used to try to prevent recurrent pericarditis but can interact with other medicines.

When the fluid is affecting the heart, it is drained. Dudley describes pericardiocentesis as a procedure done in a dedicated X-ray room by a team of doctors, nurses, radiographers and cardiac physiologists. You may be given a sedative, the chest is numbed with local anaesthetic, and a thin needle is guided into the pericardial space using ultrasound. A thin plastic catheter may be left in place so that fluid can keep draining slowly.

Dudley sets out the risks: a very small risk of death (in the order of 1 in 1000 cases), a need for emergency heart surgery very rarely (also in the order of 1 in 1000), and a small risk of damage to the heart, blood vessels or nearby structures. It advises arranging someone to take you home, being prepared to stay overnight, and not driving for 48 hours afterwards.

The BHF says that rarely, if pericarditis symptoms continue and get worse, a pericardial window may be recommended. This is surgery which drains the inflamed lining surrounding the heart.

There is no single figure for the effusion itself, because it depends on the cause. For pericarditis, Worcestershire says most cases get better over the course of 1 to 3 weeks and that symptoms with treatment normally resolve within a week in acute pericarditis. The NHS says most people feel better within a few weeks, and the BHF says most recover within weeks but for some it can take several months.

The BHF says it is usually recommended to avoid high-intensity exercise for at least three months, and to talk to your doctor about when and how to return to exercise and work. Worcestershire says repeated episodes can happen in up to 1 in 4 cases of pericarditis.

The NHS says to call 999 for sudden chest pain that spreads to your arms, back, neck or jaw, makes your chest feel tight or heavy, started with shortness of breath, sweating and feeling or being sick, or lasts more than 15 minutes, as you could be having a heart attack. Do not drive yourself to A&E.

For sharp or stabbing chest pain that gets worse when you take a deep breath, swallow, cough or lie down, the NHS advises an urgent GP appointment or NHS 111. Worcestershire advises returning to the emergency department if pain is not controlled by medicines, if you are becoming increasingly short of breath or if you have palpitations, and seeing your GP if symptoms continue for more than a week.

Most people reach care through a GP, NHS 111 or the emergency department, depending on how urgent the symptoms are. A suspected effusion is confirmed with an echocardiogram, and drainage is carried out in a hospital cardiology unit. Dudley describes it as usually an emergency procedure but also sometimes an elective one, with a consent process in two stages.

Private cardiology clinics can arrange echocardiograms and cardiology consultations for people with breathlessness or a known effusion, and some private hospitals carry out drainage. Whichever route you use, ask for a copy of the echocardiogram report and how any follow-up scans will be arranged, so that your GP and cardiology team have the same information.