This Publication Is Searchable The Merck Manual of Diagnosis and Therapy Section 11. Hematology And Oncology Chapter 136. Cardiac involvement usually causes morbidity and mortality resulting from direct eosinophil infiltration or toxins released by the cells. Endocardial and microvascular injury initiates thrombosis, resulting in endocardial fibrosis and restrictive cardiomyopathy. Involvement of papillary muscles and chordae tendineae commonly leads to mitral or tricuspid regurgitation.
Mural thrombi provide a source for systemic or pulmonary emboli.
Such patients are less likely to develop heart disease, often require no therapy, and respond well to corticosteroids. Neurologic manifestations are variable and follow direct neural injury or focal injury caused by emboli. Current therapy has improved the prognosis. All therapy is designed to reduce the eosinophil count on the premise that the disease manifestations result from tissue infiltration by eosinophils or the release of their contents. Organ system complications should be treated aggressively.