Ejection Fraction Explained: What Your Heart's Pumping Ability Means

Ejection fraction (EF) is a measurement of how much blood your heart’s left ventricle pumps out with each contraction. It’s expressed as a percentage, with a normal range of 55-70%. An EF below 40% may indicate heart failure, while an EF of 41-49% is considered borderline. This guide explains what EF means, how it’s measured, and what your numbers say about your heart health.

What is ejection fraction?

Ejection fraction is the percentage of blood that your heart’s left ventricle pumps out to your body each time it beats. In a healthy heart, the left ventricle fills with blood during diastole (relaxation) and then contracts during systole, ejecting a portion of that blood into the aorta. The fraction ejected is the ejection fraction. For example, if your left ventricle holds 100 milliliters of blood before a beat and pumps out 60 milliliters, your ejection fraction is 60%. A normal ejection fraction ranges from 55% to 70%, according to the American Heart Association’s 2022 scientific statement on cardiac function assessment.

Why does ejection fraction matter?

Ejection fraction is a key indicator of heart health, particularly for diagnosing and monitoring heart failure. It helps doctors determine the type of heart failure (with reduced vs. preserved ejection fraction) and guides treatment decisions. A low ejection fraction means your heart is not pumping enough blood to meet your body’s needs, which can lead to symptoms like shortness of breath, fatigue, and fluid retention. According to the Heart Failure Society of America’s 2023 clinical practice guidelines, ejection fraction is also used to assess the effectiveness of treatments and to predict outcomes in patients with heart disease.

The measurement is also important for people without known heart disease. A 2024 study published in the Journal of the American College of Cardiology found that a single ejection fraction measurement can predict long-term risk of heart failure and cardiovascular death, even in asymptomatic individuals. This makes EF a valuable screening tool.

Who is this for?

This guide is for anyone who wants to understand ejection fraction, whether you’ve recently had an echocardiogram, are caring for someone with heart disease, or are simply curious about how your heart works. It’s also for those who have been told their EF is “low” or “borderline” and want to know what that means. No medical background is needed — we’ll explain the basics in plain language.

How is ejection fraction measured?

Ejection fraction is most commonly measured using an echocardiogram, which uses ultrasound waves to create images of your heart. During the test, a technician places a probe on your chest that sends sound waves through your body. The waves bounce off your heart and are converted into moving images. The doctor can then measure the volume of blood in the left ventricle before and after a beat to calculate the EF.

Other imaging methods include:

• Cardiac MRI — Provides the most accurate and reproducible EF measurements. According to the Society for Cardiovascular Magnetic Resonance’s 2020 guidelines, cardiac MRI is the gold standard for EF assessment.
• Nuclear medicine scans (MUGA) — Uses a small amount of radioactive tracer to visualize the heart’s pumping function.
• Cardiac CT — Can also measure EF, though it’s less commonly used for this purpose alone.

Method	Accuracy	Invasiveness	Typical Use
Echocardiogram	Good	Non-invasive	First-line test
Cardiac MRI	Excellent	Non-invasive	Gold standard, when available
MUGA scan	Good	Minimal (IV)	When echo is inconclusive
Cardiac CT	Good	Non-invasive	When coronary anatomy is also needed

What is a normal ejection fraction?

A normal ejection fraction is between 55% and 70%. However, “normal” can vary slightly depending on the measurement method and the individual’s age, sex, and body size. For example, the American Society of Echocardiography’s 2015 guidelines (still referenced in 2026) state that a normal EF for women is slightly higher than for men, and that EF tends to increase slightly with age. An EF of 70% or higher is sometimes seen in very athletic hearts, but it can also be a sign of a stiff heart muscle, as in hypertrophic cardiomyopathy.

What do abnormal ejection fraction numbers mean?

If your ejection fraction is below 55%, it’s considered abnormal. Here’s what the ranges mean:

• EF 41-49% — Borderline reduced. This is often called “mid-range” or “borderline” ejection fraction. It may indicate early heart damage or a condition called heart failure with mildly reduced ejection fraction (HFmrEF).
• EF 40% or less — Reduced ejection fraction. This is diagnostic of heart failure with reduced ejection fraction (HFrEF). The lower your EF, the weaker your heart’s pumping ability.
• EF 70% or higher — High ejection fraction. While this can be normal for some, it may also indicate a stiff heart muscle, as in restrictive cardiomyopathy.

It’s important to note that a single EF measurement isn’t the whole story. Your doctor will consider your symptoms, other test results, and overall health when interpreting your numbers.

What is heart failure with reduced ejection fraction (HFrEF)?

Heart failure with reduced ejection fraction (HFrEF) is a condition in which the left ventricle does not pump blood effectively. It’s defined as an ejection fraction of 40% or less. In HFrEF, the heart muscle is often weakened and enlarged, and it cannot contract with enough force to push blood out. This leads to symptoms such as shortness of breath, fatigue, and swelling in the legs and ankles.

HFrEF is a serious condition, but it is treatable. According to the American College of Cardiology’s 2022 guideline for the management of heart failure, several classes of medications have been shown to improve survival and quality of life in HFrEF, including ACE inhibitors, beta-blockers, and SGLT2 inhibitors. Device therapies, such as implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT), may also be recommended for certain patients.

What is heart failure with preserved ejection fraction (HFpEF)?

Heart failure with preserved ejection fraction (HFpEF) is a type of heart failure in which the ejection fraction is normal (≥50%), but the heart muscle is stiff and does not relax properly. This means the left ventricle cannot fill adequately, leading to reduced blood flow to the body. HFpEF is often associated with high blood pressure, diabetes, and obesity. It is now recognized as the most common form of heart failure in older adults, according to the European Society of Cardiology’s 2023 heart failure guidelines.

How does ejection fraction relate to heart failure symptoms?

Ejection fraction is used to classify heart failure, but it doesn’t always correlate with symptom severity. Some people with a low EF may have few symptoms, while others with a normal EF may experience significant symptoms. This is because heart failure symptoms are also influenced by the heart’s ability to fill, the function of the right ventricle, and other factors. Your doctor will use your EF along with your symptoms and other tests to determine the best treatment plan.

Can ejection fraction improve?

Yes, ejection fraction can improve with treatment. For example, in patients with HFrEF, medications like beta-blockers and ACE inhibitors can help the heart muscle recover and pump more effectively. A 2021 meta-analysis in the Journal of Cardiac Failure found that up to 30% of patients with HFrEF showed significant improvement in EF (defined as an increase of 10 points or more) after optimal medical therapy. Lifestyle changes, such as quitting smoking, eating a heart-healthy diet, and exercising regularly, can also support heart function.

What causes low ejection fraction?

Low ejection fraction can be caused by various conditions that damage the heart muscle, including:

• Coronary artery disease — Blocked arteries can lead to a heart attack, which damages the heart muscle.
• Heart attack — A heart attack can kill part of the heart muscle, reducing its pumping ability.
• Cardiomyopathy — Diseases of the heart muscle, such as dilated cardiomyopathy, can weaken the heart.
• Valvular heart disease — Problems with the heart valves can overwork the heart.
• High blood pressure — Long-term hypertension can stiffen the heart muscle.
• Diabetes — Diabetes increases the risk of heart disease.

According to the Centers for Disease Control and Prevention’s 2024 heart disease statistics, coronary artery disease is the most common cause of heart failure in the United States.

How to improve your ejection fraction

If your ejection fraction is low, your doctor will work with you to create a treatment plan. This may include:

1. Medications — Drugs like ACE inhibitors, ARBs, beta-blockers, and aldosterone antagonists can help improve heart function.
2. Lifestyle changes — Eating a low-sodium diet, maintaining a healthy weight, and exercising regularly can reduce the workload on your heart.
3. Devices — In some cases, an ICD or CRT may be implanted to help the heart beat more effectively.
4. Surgery — Procedures like coronary bypass surgery or valve repair may be needed to address underlying causes.

Always follow your doctor’s advice. Do not try to improve your EF on your own without medical supervision.

Ejection fraction vs. cardiac output: what’s the difference?

Ejection fraction and cardiac output are both measures of heart function, but they are not the same. Cardiac output is the total volume of blood your heart pumps per minute, calculated as heart rate times stroke volume. A normal cardiac output is about 5 liters per minute. Ejection fraction, on the other hand, is a percentage that describes the fraction of blood pumped out of the ventricle per beat. A person can have a normal ejection fraction but low cardiac output if their heart rate is slow, or vice versa.

Measure	What it tells you	Normal range
Ejection fraction	Percentage of blood pumped per beat	55-70%
Cardiac output	Volume of blood pumped per minute	4-8 L/min

What questions should I ask my doctor about ejection fraction?

If you’ve been told your ejection fraction is abnormal, it’s important to understand what it means for your health. Consider asking your doctor:

• What is my exact ejection fraction?
• What type of heart failure do I have (reduced or preserved)?
• What is the underlying cause of my low EF?
• What treatments are available, and what are the benefits and risks?
• How often should I have my EF rechecked?
• What lifestyle changes can I make to improve my heart health?

Now that you understand the basics

You now know what ejection fraction is, how it’s measured, and what your numbers mean. This knowledge can help you have more informed conversations with your healthcare provider and take proactive steps for your heart health. If you’re interested in learning more, explore our guides on heart failure symptoms, cardiac imaging tests, and lifestyle tips for a healthy heart.