Quick Summary
| Topic | Key Facts |
|---|---|
| What it measures | Percentage of blood pumped out of the left ventricle with each heartbeat |
| Normal range | 55% to 70% (some guidelines use 50% to 70%) |
| Borderline range | 41% to 49%, may indicate early or developing dysfunction |
| Reduced range | Below 40%, consistent with heart failure with reduced ejection fraction (HFrEF) |
| Who gets tested | People with symptoms of heart failure, breathlessness, swelling, or fatigue |
| Primary test | Echocardiogram (cardiac ultrasound) |
| When to see a doctor | Unexplained breathlessness, leg or facial swelling, rapid weight gain, or persistent fatigue |
What Is Ejection Fraction (EF)?
Ejection fraction (EF) is a measurement, expressed as a percentage, of how much blood the left ventricle of the heart pumps out with each contraction. A healthy heart does not empty completely with each beat. It ejects roughly half to two-thirds of the blood it holds, leaving the rest behind to maintain optimal pressure and flow.
The left ventricle is the heart's main pumping chamber, responsible for sending oxygen-rich blood to the rest of the body. When doctors refer to ejection fraction without a qualifier, they are almost always referring to the left ventricular ejection fraction (LVEF). There is also a right ventricular ejection fraction (RVEF), which measures how efficiently the right side of the heart pushes blood to the lungs, though this is assessed less routinely.
Ejection fraction is one of the most widely used indicators of heart function. According to the American Heart Association, EF helps detect and track heart failure, and a single number can guide treatment decisions, device eligibility, and ongoing monitoring.
If you have received an EF reading and are trying to understand what it means, finding a cardiologist who can walk through it with you is a practical next step. Search for a cardiologist near you to get expert guidance on your specific results.
Normal Ejection Fraction Range: What the Percentages Mean
A normal ejection fraction sits between 55% and 70%, according to guidelines published by the American Heart Association. Some institutional references use a slightly wider window of 50% to 70%, while Yancy et al. in the 2022 AHA/ACC Heart Failure Guideline (Circulation) define preserved ejection fraction as 50% or higher.
An EF of 60%, for example, is entirely normal. A healthy heart does not need to eject 100% of its blood volume per beat. As McMurray et al. noted in The Lancet (2021), ejection fraction remains one of the most reproducible and prognostically relevant cardiac parameters across all stages of heart disease.
What Different EF Numbers Mean at a Glance
| EF Range | Classification | What It Suggests |
|---|---|---|
| 55% to 70% | Normal | Heart is pumping effectively |
| 50% to 54% | Low-normal / Mildly reduced | May warrant monitoring; some guidelines classify this as borderline |
| 41% to 49% | Mildly reduced (HFmrEF) | Possible early dysfunction; further evaluation recommended |
| 40% or below | Reduced (HFrEF) | Consistent with heart failure with reduced ejection fraction |
| 75% or above | Elevated | May indicate hypertrophic cardiomyopathy; warrants further assessment |
Does a Normal EF Mean the Heart Is Healthy?
Not necessarily. A normal EF percentage means the heart is contracting and ejecting blood at an adequate rate. But it says nothing about whether the ventricle is filling properly, whether the heart muscle is stiff, or whether blood volume per beat is sufficient for the body's needs. This distinction becomes relevant in heart failure with preserved ejection fraction, discussed below.
Sex-Specific and Age-Related Variations
A meta-analysis of 10,427 healthy adults across 10 population-based studies, published in BMC Cardiovascular Disorders in January 2026, found that the pooled mean LVEF was 62.8%. The lower limit of normal sat at approximately 52% for men and 53% for women. Women consistently showed slightly higher mean LVEF values (63.7%) compared to men (61.9%). The same analysis found that an LVEF below 50% is unlikely to reflect normal function regardless of sex, age, or ethnicity.
A doctor can advise on how individual factors such as age, fitness level, and comorbidities affect interpretation of a specific EF result.
Low vs. High Ejection Fraction: What Is the Risk?
Low Ejection Fraction
An EF below 40% is the threshold used in major guidelines to define heart failure with reduced ejection fraction (HFrEF), sometimes called systolic heart failure. At this level, the heart muscle is not contracting with enough force to meet the body's circulatory demands.
Ponikowski et al. in the 2016 ESC Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure (European Heart Journal) established that an LVEF below 40% defines HFrEF, a classification that directly determines which evidence-based therapies are appropriate. As EF falls further below normal, the risk of arrhythmia, hospitalization, and other cardiac events requiring ongoing management increases.
Common causes of a low EF include:
- Coronary artery disease, where reduced blood supply weakens the heart muscle over time
- Previous heart attack, where scarring from a myocardial infarction reduces contractile function
- Cardiomyopathy, a disease of the heart muscle from viral infection, genetic factors, alcohol, or chemotherapy
- Uncontrolled high blood pressure, where sustained pressure load gradually weakens the ventricle
- Atrial fibrillation, where a persistent fast or irregular heart rate can impair pumping over time
- Severe valve disease, where abnormal valves place extra strain on the ventricle
High Ejection Fraction (Above 75%)
An EF above 75% is less common and is not inherently a sign of a stronger heart. It can indicate hypertrophic cardiomyopathy, a condition where the heart muscle thickens abnormally. In this case, the ventricle becomes smaller and ejects a higher percentage of a reduced blood volume. A doctor should evaluate elevated EF readings in the context of symptoms and imaging findings.
What About an EF Between 41% and 49%?
This range is classified as heart failure with mildly reduced ejection fraction (HFmrEF). It may represent a transitional state, early dysfunction, or recovery from a previously lower reading. It warrants clinical evaluation but does not automatically mean advanced heart disease.
Heart Failure With Normal Ejection Fraction (HFpEF)
Heart failure with preserved ejection fraction (HFpEF) occurs when the heart muscle becomes stiff and the left ventricle does not relax properly between beats, even though it contracts and ejects blood at a normal percentage. Because the ventricle is stiffer, it fills with less blood than usual. The absolute volume of blood delivered to the body with each beat is lower than normal, even if the ejection fraction percentage appears adequate.
McMurray et al. (The Lancet, 2021) identified HFpEF as accounting for roughly half of all heart failure cases, with prevalence rising in older populations.
According to the American Heart Association, HFpEF is also called diastolic heart failure because the problem lies in the diastolic phase, when the heart should be relaxing and filling rather than contracting.
HFpEF is more common in:
- Adults over 65
- Women
- People with obesity, high blood pressure, or type 2 diabetes
- Those with a history of atrial fibrillation
Symptoms of HFpEF overlap with HFrEF and may include breathlessness during physical activity, fatigue, and swelling in the legs or ankles.
How Is Ejection Fraction Measured?
The most commonly used method for measuring ejection fraction is the echocardiogram (cardiac ultrasound). An echocardiogram uses sound waves to produce real-time images of the beating heart. The clinician or sonographer traces the walls of the left ventricle at end-diastole (fully filled) and end-systole (fully contracted) to calculate the volume ejected per beat.
Other methods include:
| Test | How It Works | When It Is Used |
|---|---|---|
| Echocardiogram | Sound wave imaging; most widely available | Routine assessment, follow-up monitoring |
| Cardiac MRI (CMR) | Magnetic resonance imaging; highest geometric accuracy | Complex cases, cardiomyopathy, chemotherapy monitoring |
| MUGA scan | Nuclear imaging using a radioactive tracer; traces blood flow frame by frame | When echo quality is poor; historical standard before MRI |
| CT angiography | High-resolution imaging using contrast dye | Structural assessment alongside EF |
| Cardiac catheterization | Direct pressure and volume measurements via catheter | During interventional procedures |
EF readings can vary by a few percentage points between different modalities and between different operators using the same machine. A borderline reading on one test does not automatically confirm disease. A second test or a different imaging method may be recommended before acting on the result.
Can You Improve Your Ejection Fraction?
In many cases, yes. Ejection fraction is not always a fixed number. When the underlying cause of a reduced EF is treated, the heart muscle can recover through a process called reverse remodeling.
Ponikowski et al. (European Heart Journal, 2016) established that guideline-directed medical therapy for HFrEF can substantially improve LVEF over months of consistent treatment. Some patients who begin therapy with a significantly reduced EF see it return toward the normal range after adequate pharmacological management.
Medical Treatments That Can Raise EF
The medication classes most associated with EF improvement in HFrEF include:
- ACE inhibitors, ARBs, and ARNIs, which reduce strain on the ventricle and promote reverse remodeling
- Beta-blockers (carvedilol, metoprolol succinate, bisoprolol), which reduce sympathetic activation that can weaken the heart over time
- SGLT2 inhibitors (dapagliflozin, empagliflozin), shown in trials to improve EF and reduce hospitalizations
- Aldosterone antagonists, which reduce cardiac fibrosis and fluid overload
Device therapies such as cardiac resynchronization therapy (CRT) or implantable cardioverter defibrillators (ICDs) may be considered for patients with EF below 35% who remain symptomatic on optimal medications. A doctor can advise on which treatments apply to an individual case.
Lifestyle Changes That Support EF Improvement
Alongside medication, lifestyle adjustments play a documented supportive role:
- Cardiac rehabilitation, with structured supervised exercise programs shown to improve functional capacity and EF in HFrEF patients
- Sodium restriction, which helps manage fluid retention and reduces cardiac load
- Fluid management, where daily fluid intake may be guided by a care team in advanced heart failure
- Weight management, which decreases cardiac demand and is particularly relevant in HFpEF
- Avoiding alcohol, since alcohol-induced cardiomyopathy is reversible with abstinence in many cases
- Smoking cessation, as smoking contributes to vascular and cardiac damage over time
Signs of Heart Failure: Facial Swelling, Weight Gain, and Other Symptoms
Heart failure produces symptoms because the heart is unable to circulate blood efficiently. Fluid accumulates in the body, particularly in the lungs, legs, and abdomen, and organs receive less oxygen than they need.
Commonly reported symptoms include:
- Shortness of breath at rest or with minimal exertion, particularly when lying flat (orthopnea)
- Leg and ankle swelling (peripheral edema), a sign of fluid accumulating in the lower body
- Facial swelling or puffiness around the eyes, especially noticeable on waking, which can occur when fluid redistributes overnight in more advanced cases
- Rapid or unexplained weight gain, where gaining 2 to 3 pounds in 24 hours or 5 pounds in a week is a recognized early sign of fluid retention
- Persistent fatigue, where reduced cardiac output means muscles receive less oxygen
- Reduced appetite or nausea, which can occur when fluid congestion affects the abdomen
- Difficulty concentrating, reported in some cases where cerebral circulation is affected
Heart failure symptoms can develop gradually and may initially be attributed to aging or deconditioning before a cardiac cause is identified. Facial swelling and rapid weight gain in someone already diagnosed with heart failure are clinical signals that warrant prompt contact with a healthcare provider.
The American Heart Association advises patients with known heart failure to weigh themselves every morning and report significant changes to their care team.
When to See a Cardiologist
Most people do not have their ejection fraction measured until a symptom or incidental finding prompts a cardiac evaluation. The following situations are appropriate reasons to request an assessment.
Seek evaluation if experiencing:
- Breathlessness that limits normal activity or wakes you at night
- Swelling in the legs, ankles, or face without a clear explanation
- Unexplained weight gain of more than 2 to 3 pounds in 24 hours
- A heartbeat that feels unusually fast, irregular, or fluttering
- Persistent fatigue that does not improve with rest
- Dizziness or lightheadedness on standing or with exertion
After a heart attack or cardiac procedure:
Ejection fraction is routinely measured after a myocardial infarction. An EF measured in the days immediately following a heart attack may be lower than the eventual stable value, as stunned or hibernating myocardium can recover with treatment. Repeat assessment at three to six months is standard practice.
For people with risk factors:
Those with longstanding high blood pressure, diabetes, sleep apnea, a family history of cardiomyopathy, or prior chemotherapy with cardiotoxic agents are candidates for periodic echocardiographic screening even without symptoms.
Find a cardiologist or heart failure specialist near you through Momentary Lab's directory, or use the AI healthcare navigator to help identify the right type of specialist for your situation.
Frequently Asked Questions
What causes low ejection fraction? Low ejection fraction is most often caused by conditions that weaken or damage the heart muscle, including coronary artery disease, previous heart attack, cardiomyopathy (including dilated cardiomyopathy and chemotherapy-related damage), long-term uncontrolled high blood pressure, and persistent arrhythmias such as atrial fibrillation. In some cases the cause is reversible; in others it requires ongoing management.
What is the best ejection fraction to have? An ejection fraction between 55% and 65% is generally considered optimal. Values in the 55% to 70% range are all within the normal window. A higher number is not necessarily better. An EF above 75% may indicate a structural abnormality such as hypertrophic cardiomyopathy, and a doctor should evaluate it in context.
What is the ejection fraction equal to? Ejection fraction is calculated as: (End-diastolic volume minus End-systolic volume) divided by End-diastolic volume, multiplied by 100. In plain terms, it is the stroke volume (the blood pumped per beat) expressed as a percentage of the total blood held in the ventricle when full.
How do you increase ejection fraction? Ejection fraction can improve with guideline-directed medical therapy including ACE inhibitors, beta-blockers, ARNIs, and SGLT2 inhibitors. Cardiac rehabilitation, weight management, sodium restriction, smoking cessation, and avoiding alcohol also support recovery. The degree of improvement depends on the underlying cause and how early treatment begins. A doctor can advise on realistic expectations for individual cases.
Can stress decrease ejection fraction? Acute psychological or physical stress can temporarily affect cardiac function. A condition called Takotsubo cardiomyopathy (stress-induced cardiomyopathy) can cause a sudden, temporary drop in ejection fraction following intense emotional or physical stress. It typically resolves with supportive care over days to weeks, and EF often returns to normal. Chronic psychological stress may contribute to cardiovascular risk factors such as hypertension over time, but it does not directly lower ejection fraction in the way structural disease does.
References
- Yancy CW, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure. Circulation, 2022.
- Ponikowski P, et al. 2016 ESC Guidelines for the Diagnosis and Treatment of Acute and Chronic Heart Failure. European Heart Journal, 2016.
- McMurray JJV, et al. Heart Failure. The Lancet, 2021.
- American Heart Association. Ejection Fraction Heart Failure Measurement. heart.org.
- Taha A, et al. What is a normal left ventricular ejection fraction in healthy adults? A meta-analysis of population-based echocardiographic studies. BMC Cardiovascular Disorders, 2026.
