DEFINITION

Acute pericarditis is a symptomatic inflammation of the pericardium of sudden onset with symptoms of less than 2 weeks’ duration. Acute pericarditis may result in fibrinous secretions or the development of a pericardial effusion.

PREVALENCE AND EPIDEMIOLOGY

The true prevalence of acute pericarditis is unknown, but it may account for 1% of all emergency department visits for chest pain.¹

ETIOLOGY AND PATHOPHYSIOLOGY

There are many causes of acute pericarditis (Table 69-1).²^–⁶ The specific etiology is often unknown, thereby resulting in the diagnosis of idiopathic pericarditis. The use of a systematic approach to the diagnosis of the cause of acute pericarditis, including a detailed history, blood cultures, antibody testing, and viral testing, can reduce the number of “idiopathic” diagnoses.⁷ Viral infection is the most common cause of acute pericarditis in the United States, and is probably the etiology in patients with idiopathic pericarditis.⁸^,⁹ The most common viral agents causing acute pericarditis are coxsackievirus group B and echovirus.⁸ Viral pericarditis is usually preceded by upper respiratory infection symptoms, and typically is a self-limited disease that can be diagnosed by serologic testing of antiviral titers. Numerous systemic diseases can also result in acute pericarditis and pericardial effusion. These diseases are discussed in Chapter 70. It is difficult to distinguish cases of acute pericarditis from cases of pericardial effusion in the literature because the presence of pericardial fluid is sometimes seen as an indicator of the presence of pericarditis.