Idiopathic hypereosinophilic syndrome with Löeffler's endocarditis

Hypereosinophilic syndrome (HES), or Löeffler's endocarditis, is a heterogenous group of disorders marked by the sustained overproduction of eosinophils involving different organ systems. Cardiac involvement, recognized as endocardial thickening and left ventricular (LV) mural thrombi, is the major cause for morbidity and mortality. Herein, we present a case with idiopathic HES complicated with severe cardiac involvement, who was treated successfully with corticosteroids. Echocardiography is pivotal in diagnosis and follow-up.