the subject does not need to be in ‘steady state’.

a six-fold increase in oxygen uptake mean six-fold increase in cardiac output.

cardiac catheterization is not necessary.

cardiac output (CO) is calculated as pulmonary oxygen uptake (U) multiplied by the difference in oxygen content between arterial

blood (A) and mixed venous blood (V); CO = U(A-V).

pulmonary blood flow is equated with cardiac output.