What is the most determining factor for preload?

a. Contractility
b. Venous return
c. Ejection fraction
d. Vascular resistance

ANS: B
Preload, the filling pressure of the ventricle at the end of ventricular diastole is dependent on the level of venous return and in addition the compliance of the ventricles. Contractility is the force that the ventricle generates during each cardiac cycle and is estimated using the ejection fraction. Vascular resistance is a measurement used to determine the afterload of a ventricle, or the force the heart needs to overcome to eject the blood from the ventricles.