Table 2. Parameters of Cardiopulmonary Exercise Testing and Respiratory Muscle Strength Stratified by NYHA Functional Classa,b.
| Variables | Total (N = 66) | NYHA I (n = 23) | NYHA II (n = 32) | NYHA III (n = 11) | P Value c |
|---|---|---|---|---|---|
| VO 2 at AT, mLkg -1 min -1 | 14.9 ± 0.5 | 15.8 ± 0.8 | 14.1 ± 0.5 | 9.3 ± 0.5 d,e | <0.001 |
| Peak VO 2 , mLkg -1 min -1 | 18.9 ± 0.7 | 22.3 ± 0.9 | 18.7 ± 0.7 d | 12.2 ± 0.7 d,e | <0.001 |
| Peak RER | 1.22 ± 0.01 | 1.19 ± 0.01 | 1.22 ± 0.01 | 1.22 ± 0.01 | 0.387 |
| VE/VCO 2 slope | 32.6 ± 0.9 | 28.5 ± 1.0 | 32.8 ± 1.3 | 40.5 ± 2.3 d,e | <0.001 |
| TV/RR slope | 66.2 ± 5.0 | 82.4 ± 8.7 | 64.3 ± 7.1 | 37.9 ± 5.4 d | 0.009 |
| MIP, cm H 2 O | 79.7 ± 4.1 | 96.4 ± 6.9 | 76.1 ± 5.6 d | 55.3 ± 5.2 d | 0.024 f |
| Predicted MIP, % | 74.2 ± 3.3 | 86.3 ± 5.2 | 71.0 ± 4.6 d | 58.1 ± 6.5 d | 0.008 |
| MEP, cm H 2 O | 108.7 ± 5.5 | 129.4 ± 11.0 | 102.6 ± 6.5 | 83.3 ± 9.3 d | 0.009 |
| Predicted MEP, % | 54.4 ± 2.4 | 61.9 ± 4.6 | 51.5 ± 2.9 | 47.0 ± 6.5 | 0.061 |
| Ramp exercise time, min | 8.83 ± 0.25 | 9.87 ± 0.45 | 8.72 ± 0.25 | 7.00 ± 0.57 | <0.001 |
a Abbreviations: ANOVA, analysis of variance; AT, anaerobic threshold; MEP, maximal expiratory pressure; MIP, maximal inspiratory pressure; NYHA, New York Heart Association functional class; RER, respiratory exchange ratio; RR, respiratory rate; TV, tidal volume; VCO2, carbon dioxide output; VE, minute ventilation; VO2, oxygen uptake.
b Data are presented as means ± SE.
c P values in the analysis of variance or χ2 test.
d P < 0.05 vs. NYHA I in the post hoc test.
e P < 0.05 vs. NYHA II in the post hoc test.
f F and P value in the analysis of covariance.