Patients with congestive heart failure (CHF) have a reduced<unk>  due to their inability to deliver oxygen to skeletal muscle and other tissues.  A heart failure patient's peak<unk>  is strongly correlated to prognosis.<unk>  is quantitated using gas analyzers to assess oxygen uptake (V02), carbon dioxide production (VC02) and minute ventilation . The peak oxygen uptake (peak V02) is linearly correlated with cardiac output and skeletal muscle blood flow. Peak V02 is divided by the heart rate, is highly correlated with stroke volume.  Finally, the Fick equation uses 02 consumption to measure cardiac output:
Cardiac output = V02 / arteriovenous 02 difference (A-V 02)
Exercise capacity
Pulmonary compliance
Airway resistance
Ventilation/perfusion ratio
Cardiac output
Basal metabolic rate
Respiratory rate
Coronary flow reserve