Fig. 1
From: Venous return and mean systemic filling pressure: physiology and clinical applications
The three determinants of venous return. At equilibrium, cardiac output (CO) and venous return (VR) are similar. Venous return is the inflow of the right heart. Its three determinants are the mean systemic filling pressure (Pmsf), the right atrial pressure (RAP) and the resistance to venous return (RVr) according to the formula: venous return = (Pmsf–RAP)/RVr. LV: left ventricle, RV: right ventricle