Pericardial effusion (per-e-KAHR-dee-ul uh-FU-zhun) is the buildup of too much fluid in the double-layered, saclike structure around the heart (pericardium).

The space between these layers typically contains a thin layer of fluid. But if the pericardium is diseased or injured, the resulting inflammation can lead to excess fluid. Fluid can also build up around the heart without inflammation, such as from bleeding, related to a cancer or after chest trauma.

Pericardial effusion can put pressure on the heart, affecting how the heart works. If untreated, it may lead to heart failure or death in extreme cases.

Pericardial effusion may not cause any noticeable signs and symptoms, particularly if the fluid has increased slowly.

If pericardial effusion signs and symptoms do occur, they might include:

• Shortness of breath or difficulty breathing (dyspnea)
• Discomfort when breathing while lying down
• Chest pain, usually behind the breastbone or on the left side of the chest
• Chest fullness
• Lightheadedness or feeling faint
• Swelling in the abdomen or legs

Call 911 or your local emergency number if you feel chest pain that lasts more than a few minutes, if your breathing is difficult or painful, or if you have an unexplained fainting spell.

See your health care provider if you have shortness of breath.

Pericardial effusion can result from inflammation of the pericardium (pericarditis) after an illness or injury. In some settings, large effusions may be caused by certain cancers. A blockage of pericardial fluids or a collection of blood within the pericardium also can lead to this condition.

Sometimes the cause can't be determined (idiopathic pericarditis).

Causes of pericardial effusion may include:

• Autoimmune disorders, such as rheumatoid arthritis or lupus
• Cancer of the heart or pericardium
• Spread of cancer (metastasis), particularly lung cancer, breast cancer or Hodgkin's lymphoma
• Radiation therapy for cancer if the heart was in the area of the radiation
• Chest trauma
• Inflammation of the pericardium following a heart attack or after heart surgery or a procedure where the heart's lining is injured
• Underactive thyroid (hypothyroidism)
• Use of certain drugs or exposure to toxins
• Viral, bacterial, fungal or parasitic infections
• Waste products in the blood due to kidney failure (uremia)

A potential complication of pericardial effusion is cardiac tamponade (tam-pon-AYD). In this condition, the excess fluid within the pericardium puts pressure on the heart. The strain prevents the heart chambers from filling completely with blood.

Cardiac tamponade results in poor blood flow and a lack of oxygen to the body. Cardiac tamponade is life-threatening and requires emergency medical treatment.

To diagnose pericardial effusion, the health care provider will typically perform a physical exam and ask questions about your symptoms and medical history. He or she will likely listen to your heart with a stethoscope. If your health care provider thinks you have pericardial effusion, tests can help identify a cause.

Tests

Tests to diagnose or confirm pericardial effusion may include:

• Echocardiogram. Sound waves are used to create pictures of the heart in motion. An echocardiogram shows the heart chambers and how well the heart is pumping blood. The test can help determine the amount of fluid between the two layers of the pericardium. An echocardiogram may also show decreased heart function due to pressure on the heart (tamponade).
• Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. Sticky patches (electrodes) are placed on the chest and sometimes the arms and legs. Wires connect the electrodes to a computer, which displays the test results. Your cardiologist or another health care provider can look for signal patterns that suggest cardiac tamponade.
• Chest X-ray. An X-ray image of the chest allows a health care provider to check the size and shape of the heart. A chest X-ray can show signs of an enlarged heart if the effusion is large.

CT and MRI scans can detect pericardial effusion, although they're generally not used to look for the condition. However, pericardial effusion may be diagnosed when these tests are done for other reasons.

Treatment for pericardial effusion depends on:

• The amount of fluid buildup
• The cause of pericardial effusion
• The presence or risk of cardiac tamponade

Medications

If you don't have cardiac tamponade or there's no immediate threat of cardiac tamponade, your health care provider might prescribe one of the following medications to treat inflammation of the pericardium:

• Aspirin
• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin IB, others)
• Colchicine (Colcrys, Mitigare)
• A corticosteroid, such as prednisone

Surgery or other procedures

Your health care provider may recommend procedures to drain a pericardial effusion or prevent future fluid buildup if:

• Medications don't correct the pericardial effusion
• A large effusion is causing symptoms and increasing the risk of cardiac tamponade
• You have cardiac tamponade

Drainage procedures or surgery to treat pericardial effusion may include:

• Fluid drainage (pericardiocentesis). A health care provider uses a needle to enter the pericardial space and then inserts a small tube (catheter) to drain the fluid. Imaging techniques, typically echocardiography, are used to guide the work. Usually, the catheter is left in place to drain the pericardial space for a few days to help prevent future fluid buildup. The catheter is taken out when all the fluid has drained and isn't re-accumulating.
• Open-heart surgery. If there's bleeding into the pericardium, especially due to recent heart surgery or other complicating factors, open-heart surgery may be done to drain the pericardium and repair any damage. Sometimes, a surgeon may create a passageway that allows fluid to drain as needed into the abdominal cavity, where it can be absorbed.
• Removal of the pericardium (pericardiectomy). If pericardial effusions continue to occur despite drainage procedures, a surgeon may recommend removing all or part of the pericardium.

If your pericardial effusion is discovered as a result of a heart attack or another emergency, you won't have time to prepare for your appointment. Otherwise, you'll likely start by seeing your primary care provider. You might be referred to a doctor who specializes in heart diseases (cardiologist).

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before a specific test. Make a list of:

• Your symptoms, including any that seem unrelated to your heart or breathing
• Key personal information, including major stresses, recent life changes and medical history
• All medications, vitamins or supplements you take, including doses
• Questions to ask your health care provider

Take a family member or friend along, if possible, to help you remember the information you receive.

For pericardial effusion, some basic questions to ask your doctor include:

• What's likely causing my symptoms?
• What tests do I need?
• Should I see a specialist?
• How severe is my condition?
• What's the best course of action?
• I have other health conditions. How can I best manage these conditions together?
• Are there brochures or other printed material I can have? What websites do you recommend?

What to expect from your doctor

Your health care provider is likely to ask you a number of questions, including:

• When did symptoms begin?
• Do you always have symptoms or do they come and go?
• What, if anything, seems to improve your symptoms? For example, is your chest pain less severe when you sit and lean forward?
• What, if anything, appears to worsen your symptoms? For example, are your symptoms worse when you're active or lying down?