Chronic pericarditis is inflammation that begins gradually, is long-lasting, and results in fluid accumulation in the pericardial space or thickening of the pericardium.
Pericarditis is considered chronic if it lasts longer than 6 months. There are two main types of chronic pericarditis.
In chronic effusive pericarditis, fluid slowly accumulates in the pericardial space, between the two layers of the pericardium.
Chronic constrictive pericarditis, which is rare, usually results when scarlike (fibrous) tissue forms throughout the pericardium. The fibrous tissue tends to contract over the years, compressing the heart. The compression prevents the heart from filling normally and causes a form of heart failure. However, because of the compression, the heart does not enlarge as it does in most types of heart failure. Because higher pressure is needed to fill the compressed heart, pressure in the veins that return blood to the heart increases. Fluid accumulates in the veins, then leaks out, and accumulates in other areas of the body, such as under the skin.
Usually, the cause of chronic effusive pericarditis is unknown. However, it may be caused by cancer, tuberculosis, or an underactive thyroid gland (hypothyroidism).
Usually, the cause of chronic constrictive pericarditis is also unknown. The most common known causes are viral infections and radiation therapy for breast cancer or lymphoma in the chest.
Chronic constrictive pericarditis may also result from any condition that causes acute pericarditis, such as rheumatoid arthritis, systemic lupus erythematosus (lupus), a previous injury, heart surgery, or a bacterial infection.
Previously, tuberculosis was the most common cause of chronic pericarditis in the United States, but today tuberculosis accounts for only 2% of cases. In Africa and India, tuberculosis is still the most common cause of all forms of pericarditis.
Symptoms include shortness of breath, coughing, and fatigue. Coughing occurs because the high pressure in the veins of the lungs forces fluid into the air sacs. Fatigue occurs because the abnormal pericardium interferes with the heart's pumping action, so that the heart cannot pump enough blood to meet the body's needs.
Other common symptoms are accumulation of fluid in the abdomen (ascites) and in the legs (edema). Sometimes fluid accumulates in the space between the two layers of the pleura, the membranes covering the lungs (a condition called pleural effusion—see see Pleural Effusion). However, chronic pericarditis does not usually cause pain.
Chronic effusive pericarditis may cause few symptoms if fluid accumulates slowly. The reason is that the pericardium can stretch gradually, so that cardiac tamponade may not occur. However, if fluid accumulates rapidly, the heart can become compressed and cardiac tamponade may occur.
Symptoms provide important clues that a person has chronic pericarditis, particularly if there is no other reason for reduced heart performance—such as high blood pressure, coronary artery disease, cardiomyopathy, or a heart valve disorder.
Echocardiography (see see Echocardiography and Other Ultrasound Procedures) is often done to confirm the diagnosis. It can detect the amount of fluid in the pericardial space and the formation of fibrous tissue around the heart. It can also confirm the presence of cardiac tamponade.
Chest x-rays may detect calcium deposits in the pericardium. These deposits develop in nearly half of the people who have chronic constrictive pericarditis.
The diagnosis can be confirmed in one of two ways.
Cardiac catheterization can be used to measure blood pressure in the heart chambers and major blood vessels. These measurements help doctors distinguish pericarditis from similar disorders.
Magnetic resonance imaging (MRI) or computed tomography (CT) can be used to determine the thickness of the pericardium. Normally, the pericardium is less than 1/8 inch (3 millimeters) thick, but in chronic constrictive pericarditis, it is usually 1/4 inch (6 millimeters) thick or more.
A biopsy may be done to help determine the cause of chronic pericarditis—for example, tuberculosis. A small sample of the pericardium is removed during exploratory surgery and examined under a microscope. Alternatively, a sample can be removed using a pericardioscope (a fiberoptic tube used to view the pericardium and to obtain tissue samples) inserted through an incision in the chest.
Laboratory tests on samples of blood and fluid from the pericardium may also be needed to help determine the cause of pericarditis.
Known causes of chronic effusive pericarditis are treated when possible. If heart function is normal, doctors take a wait-and-see approach. If the disorder causes symptoms or if an infection is suspected, surgical drainage may be done (see see Prognosis and Treatment).
For people with chronic constrictive pericarditis, bed rest, restriction of salt in the diet, and diuretics (drugs that increase the excretion of fluid) may relieve symptoms. However, the only possible cure is surgical removal of the pericardium. Surgery cures about 85% of people. However, because the risk of death from surgery is 5 to 15%, most people do not have surgery unless the disease substantially interferes with daily activities. Surgery is not done in the early stages of the disorder (before significant symptoms appear) or in the late stages (when symptoms occur at rest).
Last full review/revision August 2012 by Brian D. Hoit, MD