This is the amount of blood that is returned to the heart by the veins. This is influenced by various factors. Inspiration decreases the pressure in the  central veins and thus increases the pressure gradient between the peripheral and central veins thus augmenting venous return. Skeletal muscle contraction also milks the venous flow towards  the heart and the valves in the veins prevent gravitational return backwards. Significant veno dilatation can occur with conditions like sepsis and the use of certain drugs like nitrates. This can result in a serious fall in venous return. This can result in marked deterioration in conditions  like right ventricular infarction and pericardial tamponade.