Ejection fraction refers to how much blood the heart pumps out during a contraction. An abnormal ejection fraction can be a sign of heart failure.

Some people might need treatment to improve their ejection fraction.

In this article, we discuss the ejection fraction in more detail, including what the results mean and how to improve this measurement.

a woman increasing her ejection fraction by going for a runShare on Pinterest
Exercising regularly may help improve ejection fraction.

Ejection fraction is a measure of how well the heart is pumping blood around the body. The heart contracts and relaxes when it beats. During the contraction, it pushes blood out of large chambers called ventricles. These ventricles fill up with blood again as the heart relaxes.

Ejection fraction is the percentage of blood that the heart pushes out during a contraction. The percentage typically refers to the ejection fraction of the left ventricle, the chamber of the heart that pumps blood to the head, arms, torso, abdomen, and legs.

The ejection fraction is an important measure of heart functioning. For example, a low ejection fraction could indicate a heart condition.

A doctor might use this figure to guide treatment decisions.

There are a few ways to measure ejection fraction.

One common method involves an echocardiogram. Echocardiograms are a type of ultrasound scan that uses high frequency sound waves to create pictures of internal organs.

To perform an echocardiogram, a doctor will place a small probe on the chest. They will then move the probe around the chest to create a live image on a monitor.

Other possible tests include:

Cardiac catheterization

A doctor will thread a long, thin tube through a blood vessel to the heart. They will inject a contrast dye and then see how much of it leaves the heart through the arteries with each heartbeat.

Radionuclide ventriculography

This test, which people sometimes refer to as a MUGA scan, takes a picture of the heart using a special camera and a radioactive tracer in the blood.

Once the doctor has measured the ejection fraction, they will compare it to the typical ranges. These are as follows:

Normal ejection fraction

According to the American Heart Association, a normal ejection fraction is between 50% and 70%. A normal score means that the heart is pumping an adequate amount of blood with each contraction.

It is still possible to have heart failure with a normal ejection fraction. Doctors refer to this as heart failure with preserved ejection fraction (HFpEF) or diastolic heart failure.

It occurs when the heart muscle is too thick or stiff and does not relax enough to allow the normal volume of blood to fill up the ventricles. The heart may pump out blood at a normal rate, but the amount of blood might be too low.

The heart muscle can thicken with age. The thickening of the heart increases the risk of atrial fibrillation in older adults.

Low ejection fraction

An ejection fraction of 40% or under is low.

A low ejection fraction is another sign of heart failure or cardiomyopathy, which is a disease of the heart muscle.

In people with a low ejection fraction, the heart is not able to pump enough blood out of the heart to meet the body’s needs.

Some signs of a low ejection fraction include:

Some doctors consider an ejection fraction of 41–49% to be borderline low. This measurement could signify damage from a heart attack.

High ejection fraction

An ejection fraction of greater than 75% is high. A high ejection fraction can also indicate a heart condition.

For example, a high ejection fraction may be a sign of hypertrophic cardiomyopathy. This condition can affect people of all ages. It causes a thickening of the heart muscle and can lead to a cardiac arrest.

A person whose ejection fraction is outside of the normal range may require treatment for the underlying condition.

Some general recommendations for people with heart failure include:

  • limiting salt intake to under 2,300 milligrams per day
  • managing fluid intake
  • exercising regularly
  • maintaining a moderate weight
  • avoiding alcohol, smoking, and drug use
  • managing stress
  • identifying and treating possible causes of heart failure, such as high blood pressure

Doctors can prescribe medications to help treat heart failure. Some drugs, such as beta-blockers, can prevent the weakening of the heart muscle. Water pills, or diuretics, can relieve the swelling and shortness of breath that accompany heart failure.

If heart failure is due to high blood pressure or atherosclerosis, treating those conditions will be part of the approach.

A biventricular pacemaker is another option. This device detects when the heart rate is irregular, too fast, or too slow. To increase the heart’s output, it uses an electrical current that causes the left and right ventricles to pump together.

Ejection fraction is an important measure of heart health. An ejection fraction outside of the normal range can be a sign of heart failure.

The treatment for low ejection fraction resulting from heart failure includes lifestyle changes, medications, and, in some people, a biventricular pacemaker. Addressing the underlying causes of heart failure is also critical.