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Charles Gomersall
Aetiology
- viral infection
- enteroviruses especially Coxsackie B3 and B4
- adenoviruses, especially in younger patients
- hepatitis C virus
- Chagas' disease
- diphtheria
Pathogenesis
3 phases
- viral replication
- immune activation resulting in cytokine mediated disease
- remodeling leading to dilated cardiomyopathy
Clinical features
- fever
- symptoms of upper respiratory or gastrointestinal infection
- chest pain
- lymphocytosis
- atrial and ventricular arrhythmias
- cardiogenic shock
Investigations
ECG
- widened QRS
- left bundle branch block
- ST and T wave changes
- heart block
Echo
- impaired systolic function
- wall motion abnormalities
Endomyocardial biopsy
- Not necessary in the stage of viral replication
- Most useful between few days to weeks after resolution of a symptomatic
viral infection
- Frequency of positive biopsy in patients with myocarditis or dilated
cardiomyopathy is low (approx 10%) but is higher in patients with acute
early presentations of myocarditis
Treatment
- in unusual cases where a virological diagnosis is established early
anti-virals are indicated
- at present there is no good evidence that either steroids or intravenous
immunoglobulin improve outcome
- aggressive supportive therapy including left ventricular assist device
if necessary
Prognosis
- patients with fulminant myocarditis who develop sudden haemodynamic
compromise have a much better long term prognosis than those with mild acute
or chronic forms.
- in one study patients survival at 5.6 years was 93% in those with
fulminant myocarditis
Further reading
Liu PP, Mason JW. Advances in the understanding of myocarditis.
Circulation 2001; 104:1076-82
Robinson J, Hartling L, Vandermeer B, Crumley E, Klassen TP. Intravenous
immunoglobulin for presumed viral myocarditis in children and adults. Cochrane
Database of Systematic Reviews 2006 Issue 1
First posted 15th March 2006
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