Successful treatment for eosinophilic granulomatosis with polyangiitis causing severe myocarditis followed by cardiac magnetic resonance.

A 38-year-old woman had a history of asthma for 20 years. Bullous lesions had appeared on her left side of the back. Two months before admission, the biopsy revealed eosinophilic cellulitis. One month later, she experienced numbness in both legs. She was admitted to our hospital for emergency treatment due to chest pain and loss of consciousness. Emergency coronary angiography revealed triple-vessel vasospasm. She had cardiac arrest for 4 min during the examination. We suspected eosinophilic granulomatosis with polyangiitis due to pulmonary infiltrate, eosinophilia, and a history of illness. We, therefore, started methylprednisolone pulse therapy. Although her condition and laboratory findings improved, cardiac magnetic resonance (CMR) imaging performed on day 16 showed myocardial oedema and myocardial fibrosis on late gadolinium enhancement. Coronary angiography on day 35 revealed no spasm, and myocardial biopsy showed the absence of vasculitis. There was no improvement in myocardial oedema. CMR showed enlargement of late gadolinium enhancement and formation of a ventricular aneurysm. As myocarditis did not improve sufficiently, five courses of intravenous cyclophosphamide pulse therapy were administered. CMR on day 152 showed the disappearance of myocardial oedema. We report a unique case of successful treatment of severe myocarditis and the usefulness of follow-up CMR.