What to Know About Pericardial Effusion

Medically Reviewed by Jabeen Begum, MD on January 19, 2024
6 min read

A pericardial effusion is the buildup of excess fluid between the heart and the sac surrounding the heart, known as the pericardium.

Your pericardium is a tough, double-layered sac. It keeps your heart in a stable place in your chest as your heart beats. In healthy people, the pericardium contains about 15 milliliters (1 tablespoon) to 50 milliliters (3 1/3 tablespoons) of clear, yellow pericardial fluid. This fluid helps your heart move more easily within the sac.

If you have a pericardial effusion, hundreds of milliliters of fluid may gather in your pericardium. Its seriousness depends on what caused it, how much fluid gathers, and how fast it fills your pericardium.

Cardiac tamponade (pronounced tam-puh-naad) happens when so much fluid gathers in your pericardium that it prevents your heart from filling with blood and working properly. Cardiac tamponade is a life-threatening condition, and you need to go to the doctor right away.

When fluid builds up fast, tamponade can develop quickly with a small amount of liquid. If the fluid builds up more slowly, the pericardium has time to stretch, so tamponade may develop more slowly and involve a larger amount of liquid.

Causes of pericardial effusion include:

  • Pericarditis (inflammation of the pericardium).
  • Infections, most often caused by viruses (such as HIV) and bacteria (such as tuberculosis), but they can be due to fungus or parasites, too.
  • Autoimmune conditions, such as systemic lupus erythematosus (SLS), rheumatoid arthritis, and Sjogren syndrome.
  • Hormone disorders or problems, such as severe hypothyroidism, or ovarian hyperstimulation syndrome.
  • Trauma or injury to your chest, such as those from a car crash or punctures from knives or bullets.
  • Heart problems, such as a heart attack, heart failure, or aortic dissection (where the main blood vessel leading to your heart separates or tears).
  • Side effects from medical treatments, such as heart surgery, radiation therapy for cancer, or certain medications.
  • Complications from medical conditions, such as chronic kidney disease, kidney failure, or liver cirrhosis.

In some cases, your doctor may not be able to find a cause. Your doctor may call these idiopathic pericardial effusions.

You may or may not have symptoms. You're less likely to have symptoms if the effusion is small or develops slowly.

Symptoms may include:

  • Chest pressure or pain that may reach your arm, back, neck, or shoulder, or get worse when you breathe deeply, lie flat, or cough
  • Heart palpitations (a sensation that your heart is racing, pounding, fluttering, or skipping a beat) or a fast heartbeat
  • Shortness of breath
  • Dizziness, faintness, or lightheadedness
  • Fatigue
  • Altered mental status, such as confusion or agitation
  • Skin color changes, such as a blue or gray color to your lips or under your fingernails
  • Swelling in your belly and legs
  • Fever if you have an infection or inflammation

If effusion is large enough, it can put pressure on your surrounding tissues or nerves, which may cause symptoms such as:

  • Trouble swallowing (dysphagia)
  • Hiccups
  • Coughing or hoarseness

When there’s no inflammation of the sac, there are often no symptoms.

You are more likely to have symptoms when the effusion is large, develops quickly, or leads to cardiac tamponade. A pericardial effusion that develops into cardiac tamponade is a medical emergency and may be life-threatening.

To diagnose pericardial effusion, your doctor will likely ask questions about your medical history and do a physical examination.

You may have low blood pressure and a fast heart rate (over 100 beats per minute), muffled heart sounds, and swelling in the blood vessels in your neck. If you have cardiac tamponade, you may also have a drop in your systolic (the first or top number) blood pressure by 10 points or more when you breathe in.

Some tests that may help your doctor diagnose a pericardial effusion include:

  • An EKG, which measures the electrical activity in your heart. This will show if your heart isn't beating properly.
  • A chest X-ray, which may show a water bottle-shaped heart if you've had a large amount of fluid for a long time.
  • A CT of your chest or an MRI of your heart. These tests can show an effusion, but they are not the best tests to identify an effusion.
  • An ultrasound of your heart (echocardiogram), which can show the size of the effusion and if there's any evidence of cardiac tamponade. This is the best test to confirm a pericardial effusion.

Once your doctor has identified the effusion, they may do other tests to figure out what caused it. These tests may include:

  • Complete blood count, which may help your doctor find an infection.
  • Troponin level, which will help your doctor see if you have heart muscle damage.
  • B-type natriuretic peptide (BNP) level, which can help your doctor see if you have heart failure.
  • Thyroid-stimulating hormone (TSH), which will help your doctor see how well your thyroid is working.
  • Immune system tests, which can show if you have an autoimmune condition.
  • Pericardiocentesis (needle aspiration), where your doctor inserts a needle through your chest and takes some fluid to test. This may help your doctor find an infection in the fluid of your pericardium.

The treatment of a pericardial effusion depends on its severity and cause.

For a large effusion or cardiac tamponade, the fluid must be drained. This will likely be done through one of the following methods:

Pericardiocentesis to pull the extra fluid out with a needle. If necessary, your doctor may leave a tube in your chest (pericardial drain) for a few days to drain the fluid completely.

Surgery to remove the extra fluid. The type of procedure your doctor uses will depend on what's causing your effusion, how you are doing physically, and how well your doctors think you will handle the surgery.

This may be done using any of several procedures, such as:

Percutaneous balloon pericardiotomy. Your surgeon will use X-rays to guide them as they insert a long, thin tube with a small balloon on the end into your pericardium. They will make a small hole in it and inflate the balloon to make the hole bigger so that the extra fluid can drain out.

Emergency room thoracotomy. Your doctor may do this procedure if you have cardiac tamponade and pericardiocentesis didn't work. In this procedure, your chest is opened so that your doctor can get to your heart. They will make a cut in your pericardium and drain the fluid out.

Pericardiotomy. During this procedure, your doctor will remove all or part of your pericardium so that no fluid can collect in it.

Surgical pericardial window using video-assisted thoracoscopic surgery (VATS). Your doctor will make a small opening (a window) in your pericardium to let the fluid drain out.

Small effusions that don’t have symptoms and are due to known causes (for example, kidney failure) may require no special treatment. Your doctor will likely watch your effusion using an echocardiogram so they can see if it changes size or needs direct treatment.

If your effusion isn't dangerous and doesn't need to be drained immediately, your doctor will likely treat the cause. This will also treat the effusion. Such treatments may include:

  • Antibiotics, which will treat any bacterial infections, such as tuberculosis
  • Anti-inflammatory drugs, which will reduce any inflammation and swelling
  • Chemotherapy and radiation therapy if you have cancer
  • Diuretics and other medicines if you have heart failure

A pericardial effusion is excess fluid between your heart and the sac (pericardium) surrounding your heart. It can be caused by several things but may develop because of an infection that makes your pericardium swell. You may or may not have symptoms, but you're more likely to have them if the amount of fluid is large or develops fast. Pericardial effusion can develop into cardiac tamponade, which is a medical emergency. If you have symptoms such as chest pressure or pain, shortness of breath, and dizziness, go to the ER as soon as possible.