When the EF (ejection fraction indicates the amount of blood pumped with heartbeat), it almost always is the result of a heart wall impairment. A damaged heart wall is unable to contract forcefully and as a result a low EF. Normal EF is 50 to 70%.
Damaged heart walls can be the result of a prior heart attack that harmed heart cells. Heart cells can be damaged due to toxins (alcohol, drugs medication), due to blocked vessels, prior illness, etc.