Kinetics of oxygen uptake at onset of exercise related to cardiac output, but not to arteriovenous oxygen difference in patients with chronic heart failure

Patients with chronic heart failure performed exercise tests to evaluate th e relation of kinetics of oxygen uptake to cardiac output and arteriovenous oxygen difference at the onset of exercise. The kinetics of oxygen uptake are primarily determined by cardiac output; these kinetics are useful in ev aluating exercise intolerance and cardiac output response during exercise.