Ejection fraction measures your heart’s ability to pump oxygen-rich blood out to your body. In a healthy heart, the fraction is a higher number. A low number means that your heart has difficulty keeping up with your body’s needs. If you have or are at risk for heart failure, your healthcare provider will want to know your ejection fraction.
Ejection fraction refers to how well your heart pumps blood. It is the amount of blood pumped out of your heart’s lower chambers (ventricles) each time it contracts.
To understand ejection fraction, it’s helpful to understand how blood flows through the heart:
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Ejection fraction in a healthy heart is 50% to 70%. With each heartbeat, 50% to 70% of the blood in your left ventricle gets pumped out to your body.
|Normal||Mildly Abnormal||Moderately Abnormal||Severely Abnormal|
|Male||52% to 72%||41% to 51%||30% to 40%||Below 30%|
|Female||54% to 74%||41% to 53%||30% to 40%||Below 30%|
|52% to 72%|
|41% to 51%|
|54% to 74%|
|41% to 53%|
Some people with a normal ejection fraction also have heart failure. This is known as heart failure with preserved ejection fraction (HFpEF).
Your ejection fraction is an indicator of how well your heart is working. A low ejection fraction typically means you have or are at risk for heart failure.
Measurements can be taken on either the left or right ventricle.
Ejection fraction typically refers to the left side of the heart. It shows how much oxygen-rich blood is pumped out of the left ventricle to most of the body’s organs with each contraction. LVEF helps determine the severity of dysfunction on the left side of the heart.
This measures the amount of oxygen-poor blood pumped out of the right side of the heart to the lungs for oxygen. It is important if you have right-sided heart failure. But this condition is not as common as left-sided heart failure.
The ejection fraction (EF) formula equals the amount of blood pumped out of the ventricle with each contraction (stroke volume or SV) divided by the end-diastolic volume (EDV), the total amount of blood in the ventricle. To express as a percentage, you would multiply by 100. So, EF = (SV/EDV) x 100.
In other words, the ejection fraction is the percentage of blood pumped out of the ventricle after a contraction.
The lower the ejection fraction, the weaker your heart’s pumping action is. This occurs in people with severe heart failure. You can also have a low ejection fraction in the earlier stages of heart failure. Different treatments can help, depending on how far from normal your ejection fraction is.
With preserved ejection fraction (diastolic heart failure), contractions pump a large portion of blood out to your body. But the left ventricle holds a lower volume of blood. This is often because thick or stiff heart tissue effectively shrinks ventricle size. When this happens, the amount of blood pumped out to the body isn’t enough to meet its needs.
You may be at risk for heart failure with preserved ejection fraction if you have:
An ejection fraction outside of the normal range could mean a variety of things:
Ventricular contractions that pump blood out to the body need healthy muscle tissue. Conditions that weaken or damage heart muscles make contractions incomplete and less effective.
The heart may compensate by working harder to do its job. The extra work can lead to swelling or scar tissue buildup that affects the ventricle’s ability to fill and pump. You might not feel the effects of a slightly reduced ejection fraction. But as your heart function declines and your ejection fraction worsens, you can become severely ill.
The lower your ejection fraction, the more severe your heart failure symptoms may be. You might experience:
An ejection fraction of 75% or more is rare but could be dangerously high. It can occur in people with hypertrophic cardiomyopathy.
It’s helpful to know your ejection fraction if you have or are at risk for a condition that can lead to heart failure.
It helps healthcare providers determine which heart failure treatment is best for your needs. Periodically checking ejection fraction throughout therapy shows whether heart function is improving.
Heart failure treatments include:
There are a few methods for measuring ejection fraction. Echocardiogram is the most common.
Other heart tests that measure ejection fraction include:
Heart failure therapies treat the underlying cause of low ejection fraction. For heart failure due to an arrhythmia, you may benefit from a biventricular pacemaker. People with heart failure due to other causes, like high blood pressure, may need medications.
You can take additional steps to relieve strain on your heart and get the most out of treatment. These include:
If you have a low ejection fraction, you’ll have frequent appointments with your healthcare provider to monitor it. It’s essential to go to all appointments, even if you don’t feel sick.
If your symptoms are fading, it may be a sign that ejection fraction is improving. But it’s also possible for symptoms to worsen or for new ones to appear. These issues may indicate a worsening ejection fraction.
Contact your healthcare provider immediately — do not wait until your next appointment — if you experience:
Healthcare providers may be concerned about your ejection fraction if you:
The frequency of testing after a heart failure diagnosis depends on a variety of factors, including how low your initial ejection fraction reading was. If your ejection fraction continues worsening, you’ll need it checked more frequently. If it is stable, you might not need it checked as often.
Ejection fraction is one of many parameters your healthcare providers use to assess heart failure. Additional testing makes it possible to pinpoint the cause so that you receive appropriate therapies.
These tests may include:
A note from Cleveland Clinic
Ejection fraction is an indicator of heart strength. It measures the amount of oxygen-rich blood pumped out to the body with each heartbeat. A low ejection fraction is typically a sign of heart failure. With treatments and self-care, it’s possible to raise your ejection fraction back into normal range.
Last reviewed by a Cleveland Clinic medical professional on 07/07/2022.
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