Figure 1.
Means ± SD values for VD/VT (closed circles) and VD/VTVDM (open circles) measured at rest and during exercise in controls (A, left) and patients with HFpEF (B, right). **Significant difference between VD/VT and VD/VTVDM at the P < 0.01 level. Differences in VD/VT measurements were compared between calculation (with and without correcting for VDM) and across conditions (rest, submaximal exercise, and peak exercise) using a two-way repeated-measures ANOVA in patients with HFpEF and controls, separately. HFpEF, heart failure with preserved ejection fraction; VDM, mechanical dead space; VD/VT, dead space to tidal volume.