Condition characterized by hypertrophy of the wall of the left ventricle and conversion of the endocardium into a thick fibroelastic coat, with the capacity of the ventricle sometimes reduced, but often increased.

Endocardial fibroelastosis (EFE) is a rare heart disorder usually occurring in children two years old and younger. It may also be considered a reaction to stress, not necessarily a specific disease. It should not be confused with endomyocardial fibrosis..