Inflammation of the pericardium, the double-layered membrane around the heart
The pericardium is a two-layered membrane that surrounds the heart. In pericarditis, this membrane becomes inflamed, usually due to infection. The inflammation is usually acute with symptoms that are often mistaken for a heart attack (see Myocardial infarction). The inflammation usually subsides after about a week. However, rarely, the inflammation persists and causes the pericardium to become scarred and thickened and to contract around the heart. As a result, the constricted heart is unable to fill and pump normally. This serious long-term condition is called constrictive pericarditis. In both acute and long-term disorders, fluid may accumulate between the two layers of the pericardium and stop the heart from pumping effectively. This is called a pericardial effusion and may lead to acute heart failure or chronic heart failure.
In young adults, pericarditis is usually due to a viral infection, although pericarditis may develop as a complication of bacterial pneumonia. Tuberculosis is an important cause of pericarditis in some countries. A heart attack can cause pericarditis if the muscle on the surface of the heart is affected. Pericarditis may also develop when a cancerous tumour elsewhere in the body spreads to the pericardium.
Inflammation of the pericardium is also associated with autoimmune disorders, in which the body attacks its own tissues. For example, the conditions rheumatoid arthritis and systemic lupus erythematosus may sometimes cause pericarditis.
The symptoms of acute pericarditis develop over a few hours and last for about 7 days. They include:
Pain in the centre of the chest, which worsens when taking a deep breath and is relieved by sitting forwards.
Pain in the neck and shoulders.
In chronic constrictive pericarditis or when excess fluid builds up in the pericardium, the heart may be unable to fill with blood and pump it around the body effectively. Poor circulation may then lead to further symptoms that develop over a few months, such as breathlessness and swelling of the ankles and abdomen. An irregular heartbeat may also develop (see Atrial fibrillation).
Pericarditis requires assessment and treatment in hospital. The doctor will probably arrange for you to have a chest X-ray and an ECG to monitor the heart’s electrical activity. Echocardiography may be carried out to image the interior of the heart. This technique allows the thickness of the pericardium to be measured and can detect fluid around the heart. Blood tests can check for infection or autoimmune disease. You will probably be given nonsteroidal anti-inflammatory drugs to relieve chest pain and to help reduce the inflammation.
When pericarditis is caused by a viral infection, the infection should clear up within a week without further treatment. In other cases, the treatment is directed at the underlying cause. For example, antibiotics may be prescribed for bacterial infections, corticosteroids for autoimmune disorders, and antituberculous drugs to treat tuberculosis infection.
Fluid in a pericardial effusion may be withdrawn through a needle passed through the chest wall. If the effusion recurs, a piece of pericardium may be removed surgically, allowing the fluid to drain continuously. In chronic constrictive pericarditis, surgery may be needed to remove most of the pericardium and allow the heart to fill and pump freely.
Most people who have viral pericarditis recover within a week, but about 1 in 10 has a recurrence in the first few months afterwards. Pericarditis may recur if it is due to an autoimmune disorder. Surgery for chronic constrictive pericarditis is successful in only a minority of cases.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.