Diagnosing Pericarditis -- American Family Physician

Etiology Although viral infection is the most common cause of pericarditis, the condition has many possible causes (Table 1), including bacterial infection, myocardial infarction, trauma, malignancy, uremia, hypothyroidism, collagen vascular disease, and the effects of certain drugs, notably hydralazine (Apresoline) and procainamide (Pronestyl). Purulent pericarditis as a result of bacterial infection (e.g., tuberculosis) is now rare, but human immunodeficiency virus infection has become an increasingly common cause of the condition. Many infections that cause pericarditis, particularly fungal and nonbacterial infections, occur most often in immunocompromised patients. Pericarditis may complicate myocardial infarction on the second to fourth day after the acute event as a reaction to underlying necrotic myocardium. The condition may also be a P ericarditis is inflammation of the pericardial sac surrounding the heart and the origins of the great vessels. The condition is most often caused by a viral infection and generally resolves in a few weeks with no sequelae. Severe pericardial syndromes are relatively uncommon, and their clinical features are largely determined by the amount and type of fluid produced by the inflammatory process. The normal pericardial sac contains 15 to 20 mL (maximum: 50 mL) of serous fluid, which lubricates cardiac motion. In pericarditis, the accumulation of serous fluid, inflammatory cells, and fibrin may compromise cardiac function. Over time, pericarditis can result in chronic inflammation with thickening and, ultimately, calcification of the pericardium. This condition is known as “chronic constrictive pericarditis.” Conversely, rapid accumulation of serous fluid can result in acute compression of the cardiac chambers, with dire hemodynamic consequences. This condition, which is called “cardiac tamponade,”may occur in up to 15 percent of patients with severe pericarditis. Pericarditis can mimic other conditions, especially myocardial infarction. Family Pericarditis, or inflammation of the pericardium, is most often caused by viral infection. It can also develop as a result of bacterial or other infection, autoimmune disease, renal failure, injury to the mediastinal area, and the effects of certain drugs (notably hydralazine and procainamide). The clinical features of pericarditis depend on its cause, as well as the volume and type of effusion. Patients with uncomplicated pericarditis have pleuritic-type chest pain that radiates to the left shoulder and may be relieved by leaning forward. Chest radiographs, Doppler studies, and laboratory tests confirm the diagnosis and provide information about the degree of effusion. In most patients, pericarditis is mild and resolves spontaneously, although treatment with a nonsteroidal anti-inflammatory drug or a short course of a corticosteroid may be helpful. When a large pericardial effusion is produced, cardiac function may be compromised, and cardiac tamponade can occur. In patients with longstanding inflammation, the pericardium becomes fibrous or calcified, resulting in constriction of the heart. Drainage or surgical intervention may be necessary in patients with complicated pericarditis. (Am Fam Physician 2002;66:1695-702. Copyright© 2002 American Academy of Family Physicians.) Diagnosing Pericarditis