Skip to main content Accessibility help
  • Print publication year: 2008
  • Online publication date: December 2009

2 - Myocarditis and Pericarditis

from Part I - Systems
    • By Jorge A. Fernandez, Assistant Professor of Clinical Emergency Medicine, Keck School of Medicine, University of Southern California; Director of Medical Student Education, Department of Emergency Medicine, Los Angeles County–USC Medical Center, Los Angeles, CA, Stuart P. Swadron, Associate Professor of Emergency Medicine, Keck School of Medicine, University of Southern California; Residency Program Director, Los Angeles County–USC Medical Center, Los Angeles, CA
  • Edited by Rachel L. Chin, University of California, San Francisco
  • Publisher: Cambridge University Press
  • DOI:
  • pp 9-14



Cardiac infections are classified by the affected site: endocardium, myocardium, or pericardium. As the pathophysiology, clinical presentation, differential diagnosis, and treatment of myocarditis and pericarditis overlap significantly, these will be discussed together.


Myocarditis is an inflammation of the myocardium; the term myopericarditis describes the frequent additional involvement of the pericardium. Pericarditis involves only the pericardium. Isolated myocarditis is often relatively asymptomatic and therefore frequently misdiagnosed. Thus, the true incidence is unknown, although autopsy studies have demonstrated occult myocarditis in up to 1% of the general population. For unclear reasons, young men more frequently develop myocarditis as well as pericarditis.

The pericardium provides a protective barrier and is composed of two layers: visceral and parietal. The visceral layer is firmly attached to the epicardium, whereas the parietal layer moves freely within the mediastinum. Approximately 20 mL of fluid is normally present within the pericardial sac. Fluid accumulation within the pericardial sac may result in cardiac tamponade if the pericardium does not have sufficient time to stretch, as compliance increases slowly over time. Thus, the rate rather than the absolute amount of fluid accumulation in the pericardial sac is the most important determinant of tamponade physiology.

Cardiac infections may spread directly from one intracardiac region to another (from endocardium toward pericardium or vice versa). Alternatively, pleural or mediastinal infections can extend into the pericardium and cause cardiac infections.

Acker, M A. Mechanical circulatory support for patients with acute-fulminant myocarditis. Ann Thorac Surg 2001 Mar;71(3 Suppl):S73–6.
Barbaro, G, Fisher, S D, Gaincaspro, G, Lipshultz, S E. HIV-associated cardiovascular complications: a new challenge for emergency physicians. Am J Emerg Med 2001 Nov;19(7):566–74.
Carapetis, J R, McDonald, M, Wilson, N J. Acute rheumatic fever. Lancet 2005; Jul 9–15;366(9480):155–68.
Cilliers, A M, Manyemba, J, Saloojee, H. Anti-inflammatory treatment for carditis in acute rheumatic fever. Cochrane Database Syst Rev 2003;(2):CD003176.
Meune, C, Spaulding, C, Lebon, P, Bergman, J F. Risks versus benefits of NSAIDs including aspirin in myocarditis: a review of the evidence from animal studies. Drug Saf 2003;26(13):975–81.
Pawsat, D E, Lee, J Y. Inflammatory disorders for the heart. Pericarditis, myocarditis, and endocarditis. Emerg Med Clin North Am 1998 Aug;16(3):665–81.
Ross, A M, Grauer, S E. Acute pericarditis. Evaluation and treatment of infectious and other causes. Postgrad Med 2004 Mar;115(3):67–75.
Stollerman, G H. Rheumatic fever in the 21st century. Clin Infect Dis 2001 Sep 15;33(6):806–14.
Trautner, B W, Darouiche, R O. Tuberculous pericarditis: optimal diagnosis and management. Clin Infect Dis 2001 Oct 1;33(7):954–61.
Brady, W J, Ferguson, J D, Ullman, E A, Perron, A D. Myocarditis: emergency department recognition and management. Emerg Med Clin North Am 2004 Nov;22(4):865–85.
Chan, T CBrady, W JPollack, M.Electrocardiographic manifestations: acute myopericarditis. J Emerg Med. 1999 Sep–Oct;17(5):865–72.
Troughton, R W, Asher, C R, Klein, A L, Pericarditis. Lancet 2004 Feb 28;363(9410):717–27.