Pericarditis

The pericardium encloses most of the heart, the ascending aorta, the pulmonary trunk, and the terminal segment of the venae cavae. Serving primarily to anchor the heart in the central thorax and reduce its contact with surrounding structures, the pericardium is composed of two layers, a serous visceral layer adherent to the heart and a fibrous parietal layer. The space between the two layers is lubricated by a small amount of clear fluid, an ultrafiltrate of plasma. The pericardium receives its blood supply from the internal mammary arteries and is innervated by the phrenic nerves.

Acute pericarditis is an inflammatory condition that can arise from a wide variety of causes, most commonly infection, autoimmune disease, rheumatic fever, uremia, malignancy, as a reaction to a drug, or after cardiac surgery. Up to one third of cases have no identifiable cause and are considered idiopathic.

Viral infection is the most common cause of pericarditis in children. In most cases, patients report a 10- to 14-day prodrome of respiratory or gastrointestinal illness. Coxsackievirus, echovirus, adenovirus, Epstein-Barr virus, influenza virus, and human immunodeficiency virus are some of the most common responsible agents. Patients who have viral pericarditis present with fever and chest pain, and most have a friction rub. Viral pericarditis, unlike the other infectious disorders, often is accompanied by myocarditis.

Bacterial pericarditis, although less common, is associated with a higher …