Biventricular thrombus in hypereosinophilic syndrome presenting with shortness of breath

A 48 years old male presented to clinic with 12 months of low grade fever with shortness of breath which has progressively worsened with no associated weight loss, night sweats or loss of appetite. There was no prior history of chronic illness before the current illness. Laboratory workup revealed a high white blood cell count with predominant eosinophils. Chest X-ray was normal. Transthoracic echocardiography and Cardiac Magnetic Resonance showed biventricular thrombi. On further extensive workup the findings were consistent with hypereosinophilic syndrome. The patient was started on oral steroids, hydroxyurea, imatanib mesylate and oral anticoagulation. The patient responded to the treatment with complete resolution of his symptoms over the course of few months. The repeat Echocardiogram after a year showed normal left ventricular systolic and diastolic function with complete resolution of biventricular thrombi.