Ejection Fraction Percentage: What Does Yours Mean?

It measures the amount of blood pumped out of your heart’s lower chambers, or ventricles. Most often, EF refers to the percentage of blood that leaves your left ventricle when your heart contracts.

Your EF can help doctors figure out if you have certain heart problems -- especially heart failure. Despite the scary-sounding name, heart failure doesn’t mean your heart stops, it just means it can’t pump as much blood as your body needs. Your EF number will also help the doctor decide which treatments are best for you, and if your treatment is working.

How Is EF Measured?

There are a few ways your doctor can find out your EF percentage. The most common is an echocardiogram, but other tests are sometimes used:

Echocardiogram. A technologist places a hand-held wand over your chest. It uses ultrasound waves to take pictures of your heart.

MRI. You’ll lie down on a bed that slides into a large magnetic tube. MRI uses a magnet, radio waves, and a computer to create clear pictures of the inside of your body, in this case your heart.

Nuclear stress test (you may also hear it called a multigated acquisition scan, or MUGA). The doctor injects a small amount of radioactive dye into a vein. As it moves through your heart, a camera makes images of your heartbeats.

What Should My EF Be?

Many consider a normal EF to be 55% to75%. If yours is 50% or lower, it’s a sign your heart -- again, usually your left ventricle -- may not pump out enough blood.

The gray area seems to be when your EF is between 50% and 55%. Some experts call this borderline.

A normal EF doesn’t always mean your heart is healthy. You could have heart failure with preserved ejection fraction, or HFpEF. It happens when your heart muscle thickens to the point that the left ventricle holds a smaller-than-normal amount of blood. Even if that chamber pumps the way it should, it doesn’t release as much oxygen-rich blood as your body needs.

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Understanding Low EF

It means there’s a problem with your heart. If your EF is below 50%, you may be on the way to heart failure. Or you could have another heart issue, like damage from a heart attack.

An ejection fraction of 40% or lower can also signal cardiomyopathy, a term that covers several diseases of the heart muscle. When your EF is low, symptoms can include:

Can EF Get Better?

There are medications that can raise your EF and improve symptoms. Your doctor may suggest:

  • Inotropes, like digoxin: They help your heart contract better.
  • Angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs): They ease stress on your heart muscle.
  • Beta-blockers: They improve symptoms by slowing your heart rate a bit to lower its workload.
  • Diuretics: They help your body get rid of extra fluid from swelling.
  • Mineralocorticoid receptor antagonist: A type of diuretic that helps your body get rid of salt and fluid without losing potassium.

Doctors also suggest these lifestyle changes for people with low EF:

  • Get regular physical activity at a level your doctor approves.
  • Take daily relaxation/rest periods.
  • Limit salt and excess fluids.
  • Cut out alcohol and tobacco.

An implantable cardiac defibrillator, a device that keeps your heart beating, can help some people with a low EF live longer.

What to Ask Your Doctor

It’s smart to play an active role in managing your health, especially if you have a low EF. Keep up with your appointments. Have your doctor explain your condition and treatment options. Here’s a list of questions you may want to ask:

  • What does my EF number mean for my health?
  • When should I have my EF tested again?
  • Should I take medications or make lifestyle changes?
  • Do I need any other tests?
  • Do you specialize in heart rhythm problems? If not, should I see a doctor who does?

WebMD Medical Reference Reviewed by James Beckerman, MD, FACC on August 16, 2017

Sources

SOURCES:

Cleveland Clinic: “Echocardiogram,” “Ejection Fraction,” “Magnetic Resonance Imaging (MRI),” “Multigated Acquisition Scan (MUGA).”

Heart Rhythm Society: “Ejection Fraction.”

Mayo Clinic: “Ejection Fraction: What does it measure?” 

American Heart Association: "Ejection Fraction Heart Failure Measurement," "HF and Your Ejection Fraction Explained,” “What is Cardiomyopathy in Adults?” 

California Pacific Medical Center: “Treatment Options for Low Ejection Fraction.” 

UpToDate: “Clinical manifestations and diagnosis of heart failure with preserved ejection fraction,” “Patient education: Heart failure (Beyond the Basics)Patient Education: Heart failure (Beyond the Basics).”

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