What Ejection Fraction Tells You About Your Heart Health — and What It Doesn’t

When people think about heart health, they may wonder how “strong” the heart is. While knowing your numbers, such as blood pressure and heart rate, are good indicators that people can track on their own, doctors may also evaluate the strength of your heart with a measure called ejection fraction. 

“For the heart to function properly, it has to both pump strongly and relax properly,” says Dr. Daniel M. McDonald, a cardiologist at NewYork-Presbyterian/Weill Cornell Medical Center. “With every heartbeat, the heart both fills with blood and ejects some of the blood. The amount of blood that is ejected is the ejection fraction.”

While ejection fraction is a useful measure to determine how your heart is pumping, it’s not necessarily an everyday number that everyone needs to know. So when should a patient ask about this measurement?

Dr. McDonald, who is also an assistant professor of medicine at Weill Cornell Medicine, spoke to Health Matters to explain what to know about ejection fraction — including what the normal range is — and how it fits in as a piece of the heart health puzzle.

Why do doctors pay attention to ejection fraction? Is it a measure everyone should know?

Ejection fraction helps to assess overall heart function, especially when heart failure is suspected. It is not a screening tool like blood pressure or a lipid panel. Symptoms that may suggest heart failure and warrant further testing include shortness of breath, fatigue, reduced exercise tolerance, leg swelling, and rapid weight gain.

What is a normal ejection fraction?

Approximately 55% to 70%. Some patients may hear that their ejection fraction is 60%, for example, and be concerned because the value is not 100%, but 60% is normal. Every time the heart beats, about 55% to 70% of the blood that fills the heart gets ejected and is directed to the rest of the body. That is the basic function of the heart: to take oxygenated, nutrient-rich blood and deliver it to the body’s other tissues and organs.

How is it measured?

Ejection fraction is most commonly measured through an echocardiogram – an ultrasound of the heart. By visualizing the heart, clinicians can get a sense of how well the heart is pumping. Other imaging modalities, such as an MRI of the heart, can also be used in select cases.

What is the difference between heart failure with preserved ejection fraction and heart failure with reduced ejection fraction (HFpEF vs HFrEF)?

In preserved ejection fraction heart failure, the heart’s main chamber, the left ventricle, pumps normally, but is too stiff to relax properly. As a result, the heart cannot fill with enough blood to meet the body’s needs. In reduced ejection fraction heart failure, the heart’s left ventricle is too weak to pump blood as well as it should.

Ejection fraction can help categorize a patient’s heart failure and determine the best treatments and possible causes. Remembering that 55% to 70% is normal:

• Preserved: 50% or higher.
• Mildly reduced: 41%-49%.
• Reduced: 40% or lower.

The prognosis is similar across the different categories, but the treatment and underlying causes may differ.

How often should ejection fraction be checked?

In heart failure patients, tracking changes in ejection fraction can be an important component of a patient’s clinical picture. It is important to remember, however, that ejection fraction is never viewed in isolation. It is always considered alongside a broader assessment that includes a patient’s symptoms, a physical exam, and other testing.

For patients with heart failure, regardless of whether the ejection fraction is reduced or preserved, a change in symptoms (for example, if a patient develops shortness of breath or notices more swelling in the body) often triggers a repeat echocardiogram. This gives an updated assessment of both the ejection fraction and other important cardiac parameters.

For heart failure patients, generally we will repeat echocardiograms periodically, but there isn’t a one-size-fits-all guideline.

What can cause heart failure – with or without a low ejection fraction?

Important causes include:

• Longstanding high blood pressure
• Heart valve disease
• Coronary artery disease
• Genetics
• Inflammatory processes
• Excessive alcohol or drug use

What are devices and advanced therapies used to treat ejection fraction and heart failure and when are they needed?

• Implantable cardioverter-defibrillator: For patients with a low ejection fraction, especially when coronary artery disease is the cause, there is an increased risk of dangerous heart rhythms. If the ejection fraction is low – usually around 35% or lower – a defibrillator should be considered. It acts as a “guardian angel” that watches for dangerous rhythms and delivers life saving therapies if needed.
• Cardiac resynchronization therapy: Select patients with reduced ejection fractions and abnormal heart conduction (an issue with the heart’s electrical system) may benefit from a specialized pacemaker that can re-synchronize a weak heart and improve ejection fraction.
• LVAD or heart transplant: For advanced heart failure, especially in cases of reduced ejection, a patient may need a left ventricular assist device (LVAD), a mechanical pump that helps the heart circulate blood through the body, or a heart transplant.

Can you improve your ejection fraction?

For reduced ejection fraction heart failure, there are several important medications that can help patients live longer, stay out of the hospital, and potentially improve ejection fraction by helping to remodel and strengthen the heart.

In addition, certain lifestyle changes are encouraged:

• Avoiding alcohol, a toxin to the heart.
• Adopting a low sodium diet. Where salt goes, fluid follows, and people can get swollen and congested.
• Exercising. Engaging in moderate intensity activity can help the body get stronger. heart failure patients should discuss with their doctors what a safe and appropriate level of activity is for them.

Symptoms to watch for—and when to call your doctor:

• Shortness of breath (especially new or worsening)
• Fatigue or reduced ability to exercise/do usual activities
• Swelling in the legs or abdomen
• Rapid weight gain (for example, more than 5 pounds in a week) which often signals fluid buildup.

If you have sudden, severe symptoms or feel you’re in distress, call 911.

What’s your takeaway message?

Knowing the ejection fraction is essential for clinicians managing patients with suspected or proven heart failure, but it is not intended for screening purposes. Heart failure is a diverse and serious condition but there are a variety of effective treatments available.