Box 1.

Investigations recommended in all patients with suspected myocarditis

Laboratory investigations Full blood count (an eosinophilia may be suggestive of an eosinophilic myocarditis) Liver function tests Renal function and electrolytes CRP and ESR (an elevated ESR in particular may suggest an underlying inflammatory condition) Plasma troponin/CK Serum BNP Imaging/Other investigations Chest X-ray Electrocardiography Transthoracic echocardiography CMR with a gadolinium-based contrast agent (except if a patient is too unstable or in select patients with an implantable device in whom CMR may be contraindicated)

BNP = brain natriuretic peptide; CK = creatine kinase; CMR = cardiovascular magnetic resonance imaging; CRP = C-reactive protein; ESR = erythrocyte sedimentation rate.