Eosinophilic Myocarditis Presenting with Ventricular Fibrillation in a 1-Year-Old Girl

Abstract

Here, we report a previously unreported infant with idiopathic hypereosinophilic syndrome-associated eosinophilic myocarditis who developed ventricular fibrillation and was rescued by an automated external defibrillator. The patient had no recurrence of arrhythmia (including ventricular fibrillation). Blood tests initially revealed an elevated brain natriuretic peptide level, and echocardiography revealed small amounts of pericardial effusion and mitral valve regurgitation. Fortunately, the patient recovered without necessitating therapeutic intervention (e.g., steroids). The eosinophil number decreased, but it did not normalize, and late gadolinium enhancement findings on cardiac magnetic resonance imaging remained positive. Therefore, careful outpatient follow-up is required.