Ejection Fraction Explained

Medically reviewed by Dr Nabila Laskar, Consultant Cardiologist (GMC 7040901). Ejection fraction (EF) is a measurement of how much blood your heart's left ventricle pumps out with each contraction. It is one of the most important numbers in cardiology and a key result from any echocardiogram.

What Is a Normal Ejection Fraction?

A normal ejection fraction falls between 55% and 70%. This means the heart pumps out 55–70% of the blood in the left ventricle with each beat. Borderline values sit between 41–54%, and a reduced ejection fraction is generally classified below 40%.

What Does a Low Ejection Fraction Mean?

A reduced ejection fraction can indicate heart failure, a previous heart attack, cardiomyopathy, or valve disease. It does not always cause symptoms early on, which is why structural screening — even without symptoms — has value.

Can Ejection Fraction Improve?

Yes. Depending on the underlying cause, ejection fraction can improve with appropriate treatment, lifestyle changes, and in some cases, time. Regular monitoring via echocardiogram tracks this progress.

How Is Ejection Fraction Measured?

Ejection fraction is calculated during an echocardiogram by measuring the volume of blood in the left ventricle before and after each heartbeat.

Frequently Asked Questions

What ejection fraction is considered heart failure?

An ejection fraction below 40% is generally classified as heart failure with reduced ejection fraction (HFrEF), though diagnosis also depends on symptoms and other clinical findings.

Can you have heart failure with a normal ejection fraction?

Yes. Heart failure with preserved ejection fraction (HFpEF) occurs when the heart's pumping percentage is normal but it doesn't relax and fill properly between beats.

How often should ejection fraction be checked?

This depends on individual risk factors and any existing diagnosis. Your cardiologist will advise an appropriate monitoring schedule.

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