These
volumes are used to determine normal cardiac output.
Stroke volume is directly related to the force of ventricular contraction. The demands placed upon the body will directly affect cardiac output in two ways. Cardiac output will increase if the blood volume within the body is increased or if the heart beats faster. Cardiac output will decrease if either of these factors decrease.
A normal, healthy heart ejects about 60% of the blood volume
present in the ventricle. Stroke volume represents the difference
between end diastolic volume (EDV), the amount of blood collected
in a ventricle during diastole, and end systolic volume (ESV),
the amount of blood remaining in the ventricle after contraction.
These
volumes are used to determine normal cardiac output.