What is pericardial effusion?

Pericardial effusion is the buildup of extra fluid in the space around the heart. If too much fluid builds up, it can put pressure on the heart. This can prevent it from pumping normally.

A fibrous sac called the pericardium surrounds the heart. This sac consists of two thin layers. Normally, there is a small amount of fluid between them. The fluid reduces friction between the two layers as they rub against each other during each heartbeat. In some cases, extra fluid can build up between these two layers, leading to a pericardial effusion.

A little fluid won’t cause much of a problem. But if too much fluid builds up, it can make it hard for the heart to expand normally. This condition is called cardiac tamponade. It usually requires emergency treatment. Because the heart can't expand normally, less blood can enter the heart from the body. This can reduce the amount of oxygenated blood going out to the body. But not all pericardial effusions cause cardiac tamponade.

In some cases, pericardial effusion develops quickly. This is known as acute pericardial effusion. Other times, the fluid builds up slowly. This is known as subacute pericardial effusion. Chronic pericardial effusion occurs when cardiac effusion happens more than once over time.

What causes pericardial effusion?

A number of conditions can cause excess fluid and inflammation in the pericardial sac, such as:

Cancer (spread from another part of the body or from the heart tissue itself)
Infection of the pericardial sac, such as from viral or bacterial infections
Inflammation of the pericardial sac (for example, because of a heart attack)
Injury (including those from medical procedures on the heart)
Immune system problems
Metabolic causes, like kidney failure with uremia
Reactions to certain medicines
Radiation

Sometimes the cause of fluid buildup is unknown.

What are the symptoms of pericardial effusion?

You may not have any symptoms. This is more often the case with a mild effusion. You might be more likely to have symptoms from whatever is causing the pericardial effusion. For example, you might have fever if you have an infection of the pericardial sac.

When effusion is more severe, you may have symptoms such as:

Chest pain or discomfort
Enlargement of the veins of the neck
Fainting
Fast breathing
Increased heart rate
Nausea
Pain in the right upper abdomen
Shortness of breath
Swelling in the arms and legs

If the effusion is very severe, it can also lead to very low blood pressure. This can cause symptoms of shock. These include:

Lightheadedness or dizziness
Cool arms and legs
Clammy skin
Weakness
Rapid breathing
Nausea or vomiting
Pale skin
Less urine output

Shock is a medical emergency.

Many of these symptoms can be caused by other health problems. Always see your healthcare provider for a diagnosis.

How is pericardial effusion diagnosed?

The process starts with a health history and a physical exam. Your healthcare provider will ask about your symptoms and past medical conditions. For symptoms of shock, it's important to find the cause quickly.

Tests may also be done, such as:

Chest X-ray to see the heart anatomy
Imaging of the chest or heart with a CT scan or MRI
Echocardiogram (echo) to look at fluid around the heart and heart motion
Electrocardiogram (ECG) to analyze the heart’s electrical rhythm

If a pericardial effusion is found, healthcare providers must try to diagnose the cause. They may use tests such as:

Analysis of the fluid removed from around the heart to check for cancer or infection
Different blood tests to diagnose infection, immune system problems, or metabolic problems

How is pericardial effusion treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is and what caused it. Chronic and acute pericardial effusions may require different treatment.

If a pericardial effusion is not severe, treatment may include:

Careful monitoring with repeated echocardiograms
Therapy aimed at the cause of the effusion, such as antibiotics for a bacterial infection, or medicines like ibuprofen for inflammation
Treatment of pain with aspirin or another medicine

A severe pericardial effusion may need to be drained. The fluid is drained with a procedure called pericardiocentesis. This procedure uses a needle and a thin, flexible tube (catheter) to drain the fluid.

In some cases, the pericardial sac may be drained during surgery. The surgeon may remove a piece of the pericardium. This is called a pericardial window, or pericardiectomy. This can also be done to help diagnose the cause of the effusion and prevent the fluid from building up again. Your healthcare provider might be more likely to do this if you've had chronic or recurring pericardial effusion.

Symptoms often improve greatly after the excess fluid is drained. The outcome of treatment may depend on the cause and severity of the condition, how quickly treatment is started, and your overall health.

What are possible complications of pericardial effusion?

Many times, there are no complications of pericardial effusion. The most serious possible complication is cardiac tamponade. If untreated, it can lead to shock, which can cause serious complications. For example, reduced blood flow to the kidneys during shock can cause the kidneys to fail. If left untreated, shock can lead multiple organs to fail, causing death. In rare cases, the pericardium can become scarred and prevent the heart from filling correctly.

What can I do to prevent pericardial effusion?

You can reduce your risk of some of the medical problems that can lead to pericardial effusion. For example, take care of your heart by:

Limiting alcohol.
Eating a heart-healthy diet.
Getting enough exercise
Staying at a healthy weight.
Seeing a healthcare provider regularly to treat your medical problems.

Many cases of pericardial effusion are not preventable.

When should I call my healthcare provider?

If you have any symptoms of pericardial effusion, call your healthcare provider right away. Call 911 if you have trouble breathing, chest pain, or symptoms of shock.

Key points about pericardial effusion

A pericardial effusion is when excess fluid builds up in the pericardial sac around the heart. This can happen for a variety of reasons.
Some pericardial effusions are small. These are unlikely to cause symptoms or major problems themselves.
A large pericardial effusion can prevent the heart from pumping normally. This is a medical emergency.
Healthcare providers can monitor small pericardial effusions and treat the underlying causes.
A person with a large pericardial effusion might need a procedure to remove fluid from around the heart.
Seek medical attention right away if you have symptoms like severe chest pain or trouble breathing.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

Know the reason for your visit and what you want to happen.
Before your visit, write down questions you want answered.
Bring someone with you to help you ask questions and remember what your provider tells you.
At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
Know why a new medicine or treatment is prescribed and how it'll help you. Also know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the results could mean.
Know what to expect if you don't take the medicine or have the test or procedure.
If you have a follow-up appointment, write down the date, time, and purpose for that visit.
Know how you can contact your provider if you have questions.

Pericardial Effusion