Myocarditis is an inflammation of the heart muscle (myocardium), usually due to a viral infection. In many cases myocarditis produces no noticeable symptoms, although severe cases may cause

  • serious disturbances of the heartbeat (cardiac arrhythmia),
  • weakness of the heart muscle (cardiomyopathy),
  • heart failure, or
  • sudden cardiac arrest.

While in most instances the inflammation subsides on its own without treatment and without causing permanent damage, more severe cases or those that become chronic may require hospitalization and medical treatment.

Myocarditis can affect people of all ages. Because it is often asymptomatic, it is sometimes diagnosed only after a young adult with heart damage due to chronic myocarditis dies unexpectedly. Patients with viral myocarditis often exhibit pericarditis (inflammation of the lining around the heart) as well.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 16 Nov 2011

Last Modified: 04 Nov 2014