Myocarditis describes a heterogeneous group of disorders characterised by myocardial inflammation in the absence of predominant acute or chronic ischaemia.
Can affect all age groups with an apparent slightly higher incidence in males than females and equal incidence in black people and white people.
May present as fulminant, acute or chronic myocarditis.
Treatment is usually supportive care and conventional heart failure therapy. More severe presentations may need aggressive vasopressor or inotropic pharmacological support or mechanical haemodynamic assist devices such as intra-aortic balloon pump or left ventricular assist device. Occasionally, some cases do not respond to conventional therapy and progress to heart transplantation or death.
Prognosis is variable but is related to presentation and underlying aetiology. Most cases of viral myocarditis are asymptomatic and spontaneously resolve. Patients who present with mild to moderate heart failure tend to improve or recover but may progress to chronic severe heart failure. Surprisingly, patients who present with fulminant, acutely decompensated heart failure almost universally recover back to baseline function, if death is prevented through management in the acute phase.
Myocarditis is clinically and pathologically defined as inflammation of the myocardium in the absence of the predominant acute or chronic ischaemia characteristic of coronary artery disease. It is a clinical syndrome of non-ischaemic myocardial inflammation resulting from a heterogeneous group of infectious, immune, and non-immune diseases. Histopathologically, it is characterised by an inflammatory cellular infiltrate with or without evidence of myocyte injury. 
Associate Professor of Medicine
Johns Hopkins University
School of Medicine
KCW declares that she has no competing interests.
Dr Katherine Wu would like to gratefully acknowledge Dr James E. Harvey and Dr Arman T. Askari, previous contributors to this monograph. JEH and ATA declare that they have no competing interests.
Professor of Medicine
School of Medicine
VA Greater Los Angeles Healthcare System
DAL declares that he has no competing interests.
Associate Professor of Pediatrics
Pediatric Cardiothoracic Intensive Care Unit
University of Michigan Congenital Heart Center
JC declares that he has no competing interests.
Assistant Professor of Clinical Medicine
University of Missouri Hospitals and Clinics
Harry S. Truman VA Hospital
LT declares that he has no competing interests.
Use of this content is subject to our disclaimer