Acute eosinophilic myocarditis in a young woman

The first stage of eosinophilic myocarditis is called the necrotizing phase. This stage of eosinophilic myocarditis of unknown cause is often fulminant and rapidly fatal, occurring predominantly in males. Here, we report a case of eosinophilic myocarditis in the acute necrotizing phase occurred without known cause in a 23-year-old Japanese female. Severe diffuse hypokinesis of the left ventricular wall motion (ejection fraction 19.3%), significant concentric edematous thickening of the left ventricular wall (20.1 mm in diastole) and a moderate amount of pericardial effusion (10 mm wide echo free space posteriorly) were revealed by echocardiography. Eosinophils were observed and degranulated eosinophilic cationic proteins were stained with antibody against eosinophilic cationic proteins (EG2) in the myocardial specimens obtained by myocardial biopsy. In spite of its severity, the disease resolved promptly with steroid therapy.