Figure 3. Changes in respiratory and cardiovascular variables during the PECO trials in normocapnic and hypercapnic COPD patients .

Change in $\dot{V}$, MAP and HR from baseline, and $P_{\mathrm{ETC}{\mathrm{O}}_2}$ during each minute of the PECO trials in normocapnic and hypercapnic COPD patients. The black bar indicates the period of circulatory occlusion. ^*Significant difference from baseline value (P < 0.05). ^†Significant difference between normocapnic and hypercapnic groups.