Hypereosinophilic thrombus causing aortic stenosis and myocardial infarction

Hypereosinophilia can cause severe endomyocardial fibrosis with subsequent restrictive cardiac disease and endocardial lesions. We present a case of a 37-year-old man with known hypereosinophilia, followed with yearly echocardiograms, who presented acutely with myocardial infarction and aortic outflow tract obstruction. At surgery, a broad based eosinophilic thrombus was found that had obstructed the aortic outflow tract. The possibility of the rapid emergence of such obstructive thrombotic lesions in hypereosinophilic syndromes warrants very close echocardiographic surveillance.