Definition and Overview
A pericardial effusion is a condition characterized by the presence of an abnormal amount of fluid between the heart and the sac surrounding it; this sac is called the pericardium, hence the name of the condition. While it is not a disease nor harmful in itself, it is often a symptom or effect of an underlying medical condition and may impair the normal functioning of the heart. This can present in small effusions, larger and more serious ones, as well as a chronic condition lasting longer than three months.
Causes of Condition
To understand what causes pericardial effusion, it is important to understand how the heart functions. The heart is wrapped in a tough and layered sac called the pericardium so that it can safely move with each beat. The sac is filled with 2 to 3 tablespoons of clear yellowish liquid called the pericardial fluid, which acts as a lubricant so the heart can move freely within the sac. Having more than this amount of fluid in the sac is an abnormal condition called pericardial effusion, which can cause the fluid to rise from 100 milliliters up to two liters.
This increase in the pericardial fluid can be caused by several factors, including the following:
- Pericarditis – A condition where the pericardium becomes inflamed, thus producing extra fluid.
- Viral infections – Identified as the most common cause of pericardial effusions, these infections may include cytomegalovirus, echovirus, coxsackievirus, or even the human immunodeficiency virus.
- Injury to the heart or the pericardium, possibly from a previous medical operation
- Myocardial infarction or heart attack
- Uremia or severe kidney failure
- Autoimmune diseases, such as rheumatoid arthritis or lupus
- Bacterial infections
However, a large percentage of pericardial effusion cases have no identified cause. These cases are classified as idiopathic pericardial effusions.
When pericardial effusion is caused by pericarditis, it is usually accompanied by several telltale symptoms, making the condition easier to diagnose. These include:
- Chest pain – This is usually a sign of pericarditis, and often feels worse when a person breathes deeply. It can be temporarily relieved by leaning forward.
- Shortness of breath
- Muscle aches
- Vomiting and diarrhea, which are signs that a viral infection is present.
However, in cases where the effusion is not caused by pericarditis, the symptoms are less pronounced. In fact, some patients do not feel any symptoms at all. Most of the time, the condition is only diagnosed when routine health screenings turn out abnormal. In such cases, it is only when the effusion becomes large and more serious that the symptoms may begin. These include:
- Shortness of breath
- Passing out
- Clammy skin
If these symptoms are experienced, patients should be brought to the emergency room, as pericardial effusions of this severity may be life-threatening.
For non-serious cases, pericardial effusion is usually diagnosed or confirmed through the following tests:
Physical examination – A doctor may be able to detect abnormal sounds when examining the chest. This is, however, not very reliable and has to be followed by other tests.
Electrocardiogram (ECG) – An electrocardiogram is a diagnostic test used for examining the electrical activity of the heart. It is done by placing electrodes over the chest to check for abnormal electrical patterns that may indicate a pericardial effusion.
Chest x-ray – A simple chest x-ray, especially when the heart’s silhouette is enlarged, can show signs of the presence of excess fluid around the heart.
Echocardiogram – This is the most effective and most important test when it comes to diagnosing pericardial effusions. An echocardiogram, also known as the ultrasound of the heart, can distinctly show the abnormal amount of fluid around the heart, thus confirming a diagnosis.
Upon successful diagnosis of pericardial effusion, the first course of action is to determine its size and the severity of the disease. If it is small, it is not likely to cause any serious problems. However, if the effusion is very large, it can impair the heart’s ability to pump blood properly, which can cause a potentially life-threatening condition called a cardiac tamponade.
Doctors also try to determine the exact cause of the disease to formulate the best treatment plan. To do so, they take a sample of the pericardial fluid and place it under examination. This procedure is called a pericardiocentesis wherein the doctor inserts a needle through the chest to access the pericardial effusion, and then draw some of the fluid from it.
Who to See and Types of Treatments Available
A pericardial effusion should be brought to the attention of a cardiologist, a medical professional specializing in conditions affecting the heart. A cardiologist will base the treatment on the severity and cause of the condition. Small effusions that do not cause symptoms and are not known to have any underlying cause do not require treatment. For minor yet chronic effusions, the first course of action is regular monitoring; treatment is not yet needed at this point. If symptoms begin to show or worsen, the excess fluid may be drained out. However, if the effusion is caused by pericarditis, treatment will include the following:
- Non-steroidal anti-inflammatory drugs or NSAIDs including Motrin, Indocin, or Aleve
- Corticosteroids such as prednisone and Solu-Medrol
In severe cases where there is a serious infection, heart impairment, or cardiac tamponade, the excess fluid has to be drained at the soonest possible time. There are two ways to do this:
Pericardiocentesis – Similar to the procedure used to take a sample of the pericardial fluid, a pericardiocentesis can also be used to drain or suction out the excess fluid in the pericardium, leaving just the right amount.
Pericardiectomy or pericardial window – This procedure is performed by making an incision in the chest to allow the surgeon to reach in and cut a certain part of the pericardium. This is effective not only in draining the excess fluid but also in preventing it from coming back. However, this is a major procedure with a higher risk than a pericardiocentesis and requires the use of general anesthetics.
LeWinter MM, Tischler MD. Pericardial diseases. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 75