Table 4.
Basic ventilatory and cardiovascular responses time aligned at the phase II on-transient pulmonary V̇O2 kinetic τ, percent change from rest to τ, or percent change from τ to end exercise
| Healthy Control Subjects |
Heart Failure Patients |
||||||
|---|---|---|---|---|---|---|---|
| Variable | PLB | FNT | ES | PLB | FNT | ES | P Value |
| At phase II V̇o2 on-kinetic τ | |||||||
| V̇e, l/min | 24 ± 6 | 24 ± 5 | 0.2 | 30 ± 6† | 21 ± 6* | 3.4 | <0.01 |
| fB, breaths/min | 24 ± 6 | 25 ± 5 | 0.2 | 26 ± 3 | 23 ± 5 | 0.8 | 0.27 |
| VT, liters | 1.12 ± 0.36 | 1.04 ± 0.27 | 0.3 | 1.22 ± 0.27 | 0.99 ± 0.14 | 1.2 | 0.13 |
| HR, beats/min | 97 ± 10 | 99 ± 10 | 0.2 | 89 ± 12 | 86 ± 15 | 0.3 | 0.33 |
| SBP, mmHg | 172 ± 14 | 166 ± 15 | 0.6 | 137 ± 18† | 127 ± 15† | 0.7 | <0.01 |
| DBP, mmHg | 68 ± 8 | 63 ± 7 | 1.1 | 62 ± 12 | 55 ± 10 | 0.7 | 0.06 |
| MAP, mmHg | 103 ± 8 | 97 ± 8 | 1.0 | 87 ± 12† | 79 ± 10† | 0.7 | <0.01 |
| Rest to τ | |||||||
| V̇e, % | 98 ± 33 | 107 ± 42 | 0.2 | 118 ± 32 | 65 ± 49* | 1.4 | 0.02 |
| fB, % | 46 ± 19 | 43 ± 18 | 0.1 | 32 ± 16 | 23 ± 27 | 0.7 | 0.24 |
| VT, % | 46 ± 40 | 45 ± 20 | 0.0 | 63 ± 19 | 31 ± 20 | 1.9 | 0.09 |
| HR, % | 37 ± 19 | 37 ± 16 | 0.0 | 28 ± 15 | 24 ± 16 | 0.4 | 0.47 |
| SBP, % | 16 ± 11 | 16 ± 9 | 0.0 | 12 ± 11 | 10 ± 9 | 0.4 | 0.65 |
| DBP, % | 0 ± 6 | −1 ± 7 | 0.1 | 4 ± 13 | −3 ± 9 | 0.5 | 0.38 |
| MAP, % | 9 ± 8 | 8 ± 6 | 0.1 | 8 ± 12 | 3 ± 8 | 0.8 | 0.47 |
| τ to end exercise | |||||||
| V̇e, % | 167 ± 22 | 154 ± 48 | 0.3 | 60 ± 38† | 113 ± 39 | 0.9 | <0.01 |
| fB, % | 31 ± 27 | 22 ± 22 | 0.4 | 14 ± 13 | 22 ± 20 | 0.3 | 0.50 |
| VT, % | 101 ± 44 | 107 ± 40 | 0.1 | 34 ± 26† | 72 ± 25 | 1.6 | <0.01 |
| HR, % | 36 ± 11 | 26 ± 14 | 0.8 | 13 ± 8† | 15 ± 13 | 0.1 | <0.01 |
| SBP, % | 40 ± 16 | 36 ± 12 | 0.3 | 18 ± 7† | 18 ± 10† | 0.1 | <0.01 |
| DBP, % | 11 ± 10 | 5 ± 7 | 0.7 | 2 ± 12 | 0 ± 3 | 0.2 | 0.16 |
| MAP, % | 27 ± 10 | 23 ± 10 | 0.5 | 11 ± 9† | 9 ± 6† | 0.2 | 0.01 |
Data are presented as means ± SD or as otherwise noted. The phase II on-kinetics pulmonary V̇o2 τ was determined via a single-exponential function using a phase I period constrained to 35 s. V̇e, minute ventilation; fB, respiratory rate; VT, tidal volume; HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure. P values reflect the overall group-by-condition effect.
Different within group, P < 0.05, following Tukey post hoc testing.
Different between group per experimental arm, P < 0.05, following Tukey post hoc testing.