A 40-year-old man who was diagnosed with bronchial asthma and eosinophilia was transferred to our hospital due to a worsening respiratory status. He was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA), and eosinophilic pneumoniae. Cardiac magnetic resonance (CMR) imaging indicated Löffler endocarditis. Treatment was initiated using intravenous methylprednisolone, cyclophosphamide, and heparin as anticoagulation therapy. Three months later, CMR showed the improvement of the LV myocardium. In this case, the early diagnosis of Löffler endocarditis by CMR could prevent systemic embolism and CMR was useful for assessing the curative effects of steroid and immunosuppressant therapy.
Keywords: Löffler endocarditis; cardiac magnetic resonance; eosinophilic granulomatosis with polyangiitis.