Venous function A fundamental determinant of cardiac performance Maximal venous return is described by the equation (Pmc-Pa)/Rv Pmc: the mean circulatory pressure Pa: the right atrial pressure RV: the venous resistanceVenous Function • A fundamental determinant of cardiac performance • Maximal venous return is described by the equation: (Pmc-Pa)/Rv • Pmc : the mean circulatory pressure • Pa : the right atrial pressure • Rv : the venous resistance