Question: how serious is an ejection fraction of 40?
Answer: Ejection Fraction (EF) 40% to 54% Pumping Ability of the Heart: Slightly below normal. Level of Heart Failure/Effect on Pumping: Less blood is available so less blood is ejected from the ventricles. There is a lower-than-normal amount of oxygen-rich blood available to the rest of the body. You may not have symptoms.