Context and Definition

Myocarditis is an acute infectious or immunologically mediated syndrome causing inflammation of the heart muscle. It is diagnosed by histological, immunological and immunohistochemical criteria.

It is an uncommon disease but it has a significant morbidity and mortality: 4 year mortality from all forms of the condition is around 56% [1]; 8.6% of adults with no evidence of coronary artery disease who died from a sudden cardiac death in the UK had post mortem evidence of myocarditis [2].

The wide range of clinical presentations and the fact that myocarditis is uncommon pose a challenge to the emergency physician. Clinicians should have knowledge of the presentation, causes and treatment of myocarditis to avoid a missed or delayed diagnosis in a patient with a potentially fatal disease.