The importance of cardiac MR in diagnosis of myocarditis in a 30-year-old man presenting with inferior ST elevation, elevated cardiac troponin but unobstructed coronary arteries.

A 30-year-old man presented with chest pain, inferior ST elevation and elevated troponin T. Emergency coronary angiography showed unobstructed coronary arteries. A clinical diagnosis of myocarditis was made. This was supported by cardiac MRI (CMR) which showed a dilated left ventricle with severely impaired systolic function, and patchy delayed gadolinium enhancement (DGE). He was admitted to the coronary care unit where he had episodes of monomorphic ventricular tachycardia (VT). He was treated with ACE inhibitors, β-blockers and corticosteroids. Targeted cardiac biopsies were taken during admission, and also 6 weeks later; none showed histological evidence of myocarditis. Repeat CMR on day 11 showed improvement in left ventricular systolic function, extent of oedema and DGE. He has subsequently had episodes of nonsustained ventricular tachycardia and evidence of established myocardial scar on CMR several months later.