Final answer:
The strength of the ventricular pumping is known as contractility, which is influenced by factors known as inotropic factors and is closely related to the Frank-Starling mechanism.
Step-by-step explanation:
The strength of the ventricular pumping is termed contractility. Contractility refers to the force of the contraction of the heart muscle, which controls stroke volume (SV), and is the primary parameter for impacting end systolic volume (ESV). The more forceful the contraction, the greater the SV and the smaller the ESV, while less forceful contractions lead to smaller SVs and larger ESVs. Factors that influence contractility are known as inotropic factors, with positive inotropic factors increasing contractility and negative inotropic factors decreasing it.
A related concept is the Frank-Starling mechanism, which states that the force of heart contraction is directly proportional to the initial length of the muscle fiber, within physiological limits. This means that the more the ventricular muscle is stretched before contraction (known as preload), the more powerful the contraction, thereby increasing SV.