A 29-year-old male had chest pain and elevated cardiac biomarkers, with no evidence of acute ischemia. His laboratory findings indicated pronounced eosinophilia. His echocardiographic, cardiac MRI and CT findings were abnormal. He underwent transbronchial biopsy of carinal lymph nodes and of lung parenchyma. Endomyocardial biopsy revealed an eosinophilic infiltrate. He was administered high dose glucocorticoids which led to rapid recovery. Test for FIP1L1-PDGFRA and other BCR-ABL1 mutations were negative. What could be the probable diagnosis?