Low rate of cardiovascular events in patients with acute myocarditis diagnosed by cardiovascular magnetic resonance

Myocarditis is a relatively common inflammatory disease that affects the myocardium. Infectious disease accounts for most of the cases either because of a direct viral infection or post-viral immune-mediated reaction. Viral myocarditis is identified in up to 9% of post-mortem examinations (1,2), has been reported in up to 12% of young adults presenting with sudden death (3-6) and is an important underlying aetiology of other myocardial diseases such as dilated cardiomyopathy (7). Myocarditis may present with a wide range of clinical forms, ranging from asymptomatic (such as 1:200 after measles vaccine) (8), mild dyspnoea or chest pain that resolves without specific therapy, to cardiogenic shock and death (9). It may simulate acute coronary syndromes and accounts of more than 50% of patients with acute chest pain, elevated troponin and normal coronary arteries in the angiogram (10)