What is constrictive pericarditis?
Constrictive pericarditis is a disorder caused by inflammation of the pericardium (the sac-like covering of the heart) with subsequent thickening, scarring, and contracture of the pericardium. As the pericardium recovers from injury or inflammation, scar tissue may form. Scar tissue makes the pericardium stiff and hard, so that the heart is unable to fill
properly with blood. Symptoms include unexplained weight loss, fatigue, breathlessness, swelling of the abdomen and heart murmurs.
When the pericardium is scarred or thickened, the heart has difficulty contracting. This is because the pericardium has shrunken or tightened around the heart, constricting the muscle's heart movement. This usually occurs as a result of tuberculosis, which now is rarely found in the United States, except in immigrant, AIDS, and prison populations. Constrictive pericarditis is a chronic form of pericarditis in which the pericardium is rigid, thickened, scarred, and less elastic than normal. The pericardium cannot stretch as the heart beats, which prevents the chambers of the heart from filling. A direct consequence is a reduced cardiac output (the amount of blood pumped by the heart). The blood backs up behind the heart, resulting in symptoms of heart failure. The inflamed pericardium may cause pain when it rubs against the heart. The most common causes of constrictive pericarditis are conditions that induce chronic inflammation of the pericardium: tuberculosis, radiation therapy to the chest, and cardiac surgery. Less frequently, constrictive pericarditis results from mesothelioma (a tumor) of the pericardium or from incomplete drainage of abnomal fluid accumulating in the pericardial sac, which can occur in purulent pericarditis or in post-surgery hemopericardium (bleeding within the pericardial sac). Constrictive pericarditis may also develop without apparent cause. The condition is relatively rare in children.
Constrictive pericarditis is notoriously difficult to diagnose and must be distinguished from restrictive cardiomyopathy and cardiac tamponade. The examination of the neck veins may show that the jugular venous pressure is elevated. Neck veins may be prominent and may not decrease when inhaling (related to increased pressure in the veins). This is called Kussmaul's sign and is caused by lack of transmission of intrathoracic respiratory changes to the pericardial space and heart chambers. Heart sounds may be weak or distant. There may be signs of hepatic (liver) congestion, such as enlargement of the liver and fluid in the abdomen (ascites).
The goal of treatment is to improve heart function. The cause must be identified and treated. This may include antibiotics, anti-tuberculosis medications, or other treatments. Diuretics are commonly prescribed in small doses to gradually decrease excess fluid. Analgesics may be needed to control pain. Decreased activity may be recommended for some cases, and a low-sodium diet may be recommended. The definitive treatment is surgical pericardiectomy -- cutting or removing the scarring and part of the pericardium. Constrictive pericarditis may be life-threatening if untreated. The condition's surgical treatment (pericardiectomy), on the other hand, has a relatively high complication rate and is usually reserved for severely symptomatic cases. For patients with radiation-induced constrictive pericarditis the long-term results of pericardiectomy are not as helpful as was once expected. |
