Stroke Volume Formula
Stroke Volume= End Diastolic Volume - End Systolic Volume
The formula for stroke volume is Stroke Volume= End Diastolic Volume - End Systolic Volume.
Stroke volume is the amount of blood that the ventricles of the heart pump out with each heart beat. The ventricles pump out this blood either into the pulmonary trunk (the right ventricle) or the aorta (the left ventricle).
The 2 variables or factors which affect stroke volume are the end diastolic volume (EDV) and the end systolic volume (ESV).
Remember that the heart goes through 2 cycles, which it repeats over and over again. Diastole is the cycle where the ventricles of the heart fill up with blood. This is when the atria contract and dump blood into the ventricles and fill the ventricles up with blood. Systole is the cycle where the ventricles contract and eject the blood into the great arteries. So diastole is when the ventricles fill up with blood. And systole is when the ventricles contract and eject the blood out.
So the end diastolic volume (EDV) is the amount of blood which the ventricles fill up to at the end of diastole.
And the end systolic volume (ESV) is the amount of blood which the ventricles contain after systole is completed. This is after the ventricles of the heart have contracted and ejected blood into the great arteries, which is the pulmonary trunk and the aorta.
Both the end diastolic volume (EDV) and the end systolic volume (ESV) are measured in unit milliliters (mL). Being that the ESV simply subtracts from the EDV, the resultant value of stroke volume is in unit milliliters (mL).
Increasing the EDV or decreasing the ESV will increase stroke volume. Decreasing the EDV or increasing the ESV will decrease stroke volume.
When a person is normally at rest, the average stroke volume is about 70 mL with each beat. Usually the end diastolic volume is about 120mL and the end systolic volume is 50mL. This gives a stroke volume of 120mL-50mL= 70mL.
Measuring a person's stroke volume is a way or test of measuring the health of a person's heart. The volume of blood which a person pumps
out each heart beat tells whether the person has a properly
functioning and normal heart.
Example Calculation of Stroke Volume Formula
If a person has end diastolic volume of 130mL and a end systolic volume of 60mL, what is the stroke volume of this individual?
So based on the values of the parameters, we use the equation SV= EDV - ESV and substitute in the values into the equation.
Stroke Volume= 130mL-60mL= 70mL
To see our calculator to calculate stroke volume online, see the
Stroke Volume Calculator.