Suspect acute pericarditis in the patient with sharp, pleuritic chest pain who gains relief by sitting up and leaning forward.  Also suspect it if you hear a pericardial friction rub — a high-pitched scratchy or squeaky sound best noted at the left sterna border, in systole, diastole, or both.

Diagnose pericarditis by an EKG, which shows S-T segment elevation in all (or, at least, in most) leads [an acute MI in all leads would be DOA].

Most pericarditis is viral, treated with NSAIDs.  Work-ups have very low yields.  Consider hospitalization only for patients with fever and leukocytosis, who appear dyspneic, or who are immunocompromised or on anticoagulants.

See posting Chest Pain – 2.