Fig. 3. Cardiac output () during 15 min of severe hypoxia (filled circles; N=8), and during 15 min of severe hypoxia with 1.5 mmol l^–1 of sodium cyanide (NaCN) added to the hypoxic perfusate (open circles; N=7). was averaged over 2 min intervals during severe hypoxia. There was no significant difference in between the treatment groups, at any point during severe hypoxia.