Loeffler Endocarditis in Idiopathic Hypereosinophilic Syndrome Demonstrated by Magnetic Resonance Imaging Effectively Treated by Corticosteroids.

Abstract

Hypereosinophilia (HE) is diagnosed with persistent eosinophilia (absolute eosinophil count > 1.5 × 109/L) recorded on two occasions at least 1 month apart.1 If there is evidence of organ damage caused by HE and exclusion of other disorders as the main reason for organ damage, it is defined as hypereosinophilic syndrome (HES). Loeffler endocarditis is a subtype of HES in which the myocardium is involved and considered to be one of the major causes of morbidity and mortality in HES.2 The definite diagnosis of Loeffler endocarditis requires myocardial biopsy, an invasive procedure bearing certain risks, which may not always be available or consented by patients. Echocardiography can assess morphological and functional changes but not myocardial tissue composition. However, cardiac magnetic resonance imaging (MRI) is able to characterize different kind of myocardial damage with satisfying resolution and can be a substitute of biopsy in the diagnosis of Loeffler endocarditis.3-6 In this case, we report an interesting case of Loeffler endocarditis in idiopathic HES, which is demonstrated by cardiac MRI and effectively treated by corticosteroids.