Hypereosinophilic Syndrome Leading to Severe Right-Sided Heart Failure in a Patient with Ebstein's Anomaly

A 36-year-old male with mild Ebstein's anomaly developed severe right-sided heart failure, following a 5-year-long course of hypereosinophilic syndrome. No regular followups had been done, during the years of antineoplastic therapy. A year after being cured from the hypereosinophilic syndrome, the patient developed right-sided heart failure symptoms and was found to have excessive fibrosis of the right ventricular endocardium and free tricuspid regurgitation. The findings were compatible with substantial scarring of the endocardium caused by the hypereosinophilic syndrome. Over a few years, the patient deteriorated significantly and was finally offered a heart transplant. Examination of the explanted heart revealed severe fibrosis of the right ventricle and almost complete sparing of the left. 1. Introduction The hypereosinophilic syndromes (HES) are a group of disorders, with sustained overproduction of eosinophils, in which eosinophilic infiltration can cause damage to multiple organs [1]. The overall prevalence of myocardial involvement is more than 50% and can be related to a poor prognosis [1, 2]. Typical cardiac manifestations are endocardial fibrosis and mural thrombosis, predominantly located in the apices of both ventricles [2–4]. The long-term prognosis depends on the degree of cardiac involvement and the likelihood of hematological malignancies later on [1]. However, cardiac disease from HES only rarely leads to end-stage heart failure or heart transplantation [5]. 2. Case Report A 36-old-male patient was referred to our department, due to severe tricuspid valve regurgitation and right-sided heart failure. At age of 29, he was diagnosed with HES and treated with hydroxyurea and prednisolone for 5 years. The patient had never had cardiac symptoms before initiation of the antineoplastic therapy, and a pretreatment echocardiogram had only shown mild Ebstein’s anomaly, with mild tricuspid valve regurgitation. Maybe for these reasons, the patient was not offered any cardiological check-ups during the course of HES. Approximately one year after being declared free of HES, including the FIP1？L1-PDGFRA gene rearrangement, the patient developed right-sided heart failure symptoms. A new echocardiogram revealed severe tricuspid regurgitation with dilatation of the right atrium. The right ventricle was found restrictive with poor systolic function; however, the acoustic windows were poor. A subsequent cardiac magnetic resonance scan revealed a small right ventricular cavity, poor systolic right ventricular function, and agglutination of the tricuspid