heart being tested for ejection fraction

How is Ejection Fraction Calculated?

Ejection fraction is a diagnostic measurement of the heart. While no heart exudes 100% of the blood that enters it, at least 50% should leave. Less than that is suggestive of damage, and less than 40% can be indicative of heart failure. 

If your doctor suspects something serious is going on, she may request to measure your ejection fraction. This is performed through imaging tests, and while there are several that can do the job, the most common tool for this measurement is an echocardiogram, an ultrasound designed specifically to examine your heart and blood flow. An echocardiogram allows your doctor a clear image of blood entering the heart and, more importantly, leaving the heart. At this point, she can calculate how much of the blood is staying behind. 

An ejection fraction of 45% means that only 45% of the blood in the ventricle is pushed out when your heart contracts. If your ejection fraction is low, your doctor will help formulate a treatment plan. If you have symptoms of heart failure and your EF is normal, you may need further testing. In one instance, which is referred to as heart failure with normal or preserved ejection fraction, the heart and ventricle walls become so thick and hard, a smaller than normal amount of blood is pumped into the heart -- this means that while it appears to be pumping out a normal amount, something still isn’t right. If you’re worried about heart failure or your EF, talk to your doctor right away. 

Last Updated: January 11, 2017

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