The ejection fraction (EF) is an important measurement in determining how well your heart is pumping out blood and in diagnosing and tracking heart failure.
A significant proportion of patients with heart failure happen to have a normal ventricular ejection fraction at echocardiography during examination. Previously called diastolic heart failure, it is nowadays referred to as heart failure with normal ejection fraction (HFNEF) or HF with preserved ejection fraction.
- Preserved ejection fraction (HFpEF) – also referred to as diastolic heart failure. The heart muscle contracts normally but the ventricles do not relax as they should during ventricular filling (or when the ventricles relax).
- Reduced ejection fraction (HFREF) – also referred to as systolic heart failure. The heart muscle does not contract effectively and less oxygen-rich blood is pumped out to the body.
What it is?
A measurement of how much blood the left ventricle pumps out with each contraction.
What does it mean?
An ejection fraction of 60 percent means that 60 percent of the total amount of blood in the left ventricle is pushed out with each heartbeat.
- A normal heart's ejection fraction may be between 55 and 70.
- You can have a normal ejection fraction reading and still have heart failure. If the heart muscle has become so thick and stiff that the ventricle holds a smaller-than-usual volume of blood, it might still seem to pump out a normal percentage of the blood that enters it. In reality, though, the total amount of blood pumped isn't enough to meet your body's needs.
What's too low?
- A measurement under 40 may be evidence of heart failure or cardiomyopathy.
- An EF between 40 and 55 indicates damage, perhaps from a previous heart attack, but it may not indicate heart failure.
- In severe cases, EF can be very low.
What's too high?
EF higher than 75 percent may indicate a heart condition like hypertrophic cardiomyopathy.
Tests for measuring EF:
Learn more about common tests for diagnosing heart failure
This content was last reviewed on 07/09/2013.