The eosinophil-mediated tissue injury associated with Idiopathic Hypereosinophilia Syndrome can create a restrictive cardiomyopathy secondary to subendocardial fibrosis. Mural thrombus deposition can impair leaflet mobility in the atrioventriular valves. This video demonstrates the surgical technique for endocardial resection with atrioventricular preservation. Echocardiographic and histologic findings are included.