amount of blood ejected by the ventricle with each beat
Ejection fraction In a healthy 70-kilogram (150 lb) man, the stroke volume is approximately 70 mL and the left ventricular end-diastolic volume (EDV) is 120 mL, giving an ejection fraction of  70⁄120, or 0.58 (58%).
Ventricle (heart) Ventricles have thicker walls than atria and generate higher blood pressures. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated by the atria to fill the ventricles. Further, the left ventricle has thicker walls than the right because it needs to pump blood to most of the body while the right ventricle fills only the lungs.