Table 5.
Characteristics of those with and without a pulmonary exercise limitation
| Pulmonary Limit |
|||
|---|---|---|---|
| Characteristic | No | Yes | P Value |
| n | 158 | 46 | |
| Age, yr | |||
| At earliest Fontan | 3.7 ± 2.5 | 3.3 ± 2.1 | 0.23 |
| At exercise testing | 13.7 ± 3.2 | 13 ± 2.6 | 0.19 |
| Height, cm | 153.1 ± 14.8 | 150.7 ± 13.5 | 0.34 |
| Weight, kg | 47.8 ± 16 | 47.4 ± 16.5 | 0.89 |
| BMI | |||
| kg/m2 | 19.8 ± 3.8 | 20.2 ± 4.2 | 0.52 |
| Z-score | 0.0 ± 1.2 | 0.2 ± 1.3 | 0.21 |
| V̇o2peak | |||
| ml·kg−1·min−1 | 25 ± 5.6 | 26.6 ± 4.5 | 0.07 |
| % predicted | 60.9 ± 12.7 | 63.7 ± 8.8 | 0.17 |
| Peak work | |||
| W | 90.6 ± 38 | 91 ± 33.1 | 0.96 |
| % predicted | 61.1 ± 15.9 | 63.1 ± 12.2 | 0.42 |
| Peak HR | |||
| beats/min | 160.4 ± 22.4 | 161.9 ± 19.6 | 0.69 |
| % predicted | 77.7 ± 10.6 | 78.2 ± 9.6 | 0.77 |
| Peak O2 pulse, % predicted | 81.5 ± 19.4 | 83.6 ± 15.7 | 0.52 |
| Peak O2 saturation, % | 90.5 ± 6.5 | 89.6 ± 6.3 | 0.47 |
| V̇e/V̇co2 | 41.3 ± 7.4 | 47.2 ± 9.1 | <0.0001 |
| Maximal voluntary ventilation, liters | 90.9 ± 29.9 | 76.5 ± 28.1 | 0.004 |
| Breathing reserve,% | 39.6 ± 11.6 | 11.0 ± 7.7 | <0.0001 |
| Peak V̇e, l/min | 54.0 ± 18.6 | 67.6 ± 24.1 | <0.0001 |
| Peak VT, liters | 1.17 ± 0.45 | 1.15 ± 0.49 | 0.84 |
| Peak RR, breaths/min | 48.2 ± 11.2 | 60.9 ± 8.7 | <0.0001 |
| VT/FVC at VAT, % | 36.4 ± 8.8 | 41.1 ± 6.5 | <0.0001 |
| Peak VT/FVC, % | 45.7 ± 8.1 | 50.7 ± 7.1 | 0.0002 |
| FEV1, liters | 2.24 ± 0.74 | 1.89 ± 0.71 | 0.006 |
| FVC, liters | 2.56 ± 0.88 | 2.2 ± 0.87 | 0.01 |
| FEV1, % predicted | 79.4 ± 14.8 | 68.7 ± 14 | <0.0001 |
| FVC, % predicted | 80 ± 14.6 | 71.9 ± 13.7 | 0.001 |
| FEV1-to-FVC ratio | 0.88 ± 0.07 | 0.86 ± 0.09 | 0.09 |
There was no significant between-group difference in resting HR, chronotropic index, resting O2 saturation, peak O2 pulse (in ml·m−2·beat−1) or peak respiratory exchange ratio (data not shown). FEV1, forced expiratory volume in 1 s.
A pulmonary limit was defined as V̇o2peak < 80% predicted and breathing reserve < 20%.