What is the volume of blood in the ventricle at the end of atrial systole called?

1. Filling ends when atrial systole finishes, just before ventricular contraction. 2. That volume is known as the end diastolic volume, also called preload. 3. End systolic volume is the leftover after ejection, a different point in the cycle. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 19 "The Cardiovascular System: The Heart", section 19.3 | Cardiac Cycle_