Cardiac involvement in hypereosinophilic syndrome.

A 27-year-old man who was known to have hypereosinophilic syndrome (HES) underwent evaluation at our echocardiography laboratory for exertional dyspnea. Laboratory tests revealed leukocytosis (5.4  10/L) with marked eosinophilia (34.6%; normal range, 4%), in addition to an elevated level of tryptase (70 ng/mL; normal range, 13.5 ng/mL). Two-dimensional transthoracic echocardiography showed an echodense structure that obliterated the left ventricular apex, consistent with thrombus and thickening of the posterobasal wall (Figs. 1 and 2). Pulsed-wave and tissue Doppler echocardiography revealed a left ventricular restrictive filling pattern (Figs. 3 and 4).