Ejection Fraction

Editorial Team / Admin · Feb 21, 2006

Ejection fraction. The left ventricle is a chamber which relaxes to fill with blood and then contracts to pump the blood out. Even in a healthy heart, the left ventricle does not pump all of the blood out with each beat. The ejection fraction is defined by the following formula:

LV diastolic volume - LV systolic volume

LV diastolic volume

(where systolic volume is the fully contracted state and diastolic volume is the fully relaxed state)

The ejection fraction is a useful measure of left ventricular performance. The normal range is 63-77% for males and 55-75% for females (reference: Measurements in Cardiology). If the left ventricle wall is thinned, a decrease in the ejection fraction is seen.

We can use computer programs in the cath lab to calculate the EF, if we do a left ventriculogram, and then trace the end systolic and end diastolic outlines.

Most of the info I found on the web (do a google or yahoo search) talked about calculating it from the measurements taken during the echo.

roxygirl82 · Feb 21, 2006

Thank you for the formula. So if I was trying to calculate a persons EF in their BP was 120/80 would it be 80-120/80 to get the EF? I think thats where I get lost at. Is the BP the LV diastolic volume and the LV systolic volume? :uhoh3:

Thunderwolf, MSN, RN · Feb 21, 2006

Moved to Cardiac Nursing forum.

carachel2 · Feb 21, 2006

Thank you for the formula. So if I was trying to calculate a persons EF in their BP was 120/80 would it be 80-120/80 to get the EF? I think thats where I get lost at. Is the BP the LV diastolic volume and the LV systolic volume?

No, you can't calculate an EF based on BP alone. You need an echocardiogram or a heart cath.

roxygirl82 · Feb 21, 2006

Thank you for telling me that. :roll

CRDCRN69 · Jul 22, 2011

That is actually not true.... you can calculate the EF w/o a left heart cath. We do it frequently in the ICU with a Pulmonary Artery (PA) catheter. The formula is: Right Heart EF= Stroke Volume (SV)/Right Ventricular End Diastolic Volume (RVEDV) or Left Heart EF= Stroke Volume (SV)/ Left Ventricular End Diastolic Volume (LVEDV). Multiple those answers by 100 to get the percentage. You can not use the blood pressure to calculate EF as the EF is based off of end diastolic volumes.

CCL RN, RN · Jul 22, 2011

No, you can't calculate an EF based on BP alone. You need an echocardiogram or a heart cath.

That is actually not true.... you can calculate the EF w/o a left heart cath. We do it frequently in the ICU with a Pulmonary Artery (PA) catheter.

This IS a heart cath. It's a right heart cath. A catheter is placed into the heart=>heart cath. So it is actually true that you need an echo or heart cath (notice the previous poster did not specify left heart).

Eegads-just realized this thread is 6 years old!!

nursej22, MSN, RN · Jul 24, 2011

Ejection fraction can also be measured during a nuclear perfusion scan.