Baseline characteristics, pulmonary function test and sleep study parameters of patients and controls
| Variable | Eisenmenger syndrome (n=25) | CCHD with decreased PBF (n=12) | p Value |
|---|---|---|---|
| Age (years) | 25.2±9.6 | 20.5±8.5 | 0.13 |
| Males | 18 (72%) | 8 (66.7%) | 1.0 |
| Sleep disturbance | 13 (52%) | 6 (50%) | NS |
| Haemoglobin (gm/dl) | 15.5±1.9 | 17.5±2.9 | 0.04 |
| Resting SpO2 (%) | 87.7±5.1 | 82.9±5.9 | 0.02 |
| 6 min distance (m) | 469.6±108.8 | 434.3±77.8 | 0.15 |
| 6 min walk SpO2 (%) | 78.4±7.5 | 73.8±6.9 | 0.11 |
| Pulmonary function tests (values % predicted) | |||
| FEV1 | 62.5±19.8 | 57.5±17.7 | 0.65 |
| FEV1/FVC | 91.5±21.9 | 85.0±20.2 | 0.90 |
| FEF(25–75) | 40.1±21.5 | 58.5±36.1 | 0.37 |
| TLC | 72.2±10.8 | 80.0±11.3 | 0.25 |
| DLCO | 70.6±4.9 | 75.3±2.6 | 0.06 |
| Polysomnogram variables | |||
| Total sleep time (min) | 388.1±122.9 | 386.2±108.5 | 0.46 |
| Sleep efficiency (%) | 94.6±6.1 | 96.7±3.3 | 0.49 |
| REM sleep (%) | 16.0±10.5 | 18.2±12.0 | 0.74 |
| Apnoea–hypopnoea index | 3.4±5.0 | 2.2±3.6 | 0.72 |
| Oxygen drop index | 9.0±6.2 | 8.0±5.9 | 0.63 |
| Mean SpO2 during sleep (%) | 84.7±5.8 | 78.1±5.8 | 0.004 |
| Lowest SpO2 during sleep (%) | 77.4±8.1 | 70.7±8.8 | 0.03 |
All values mean±SD or number (%).
CCHD, cyanotic congenital heart disease; DLCO, diffusion capacity with carbon monoxide; FEV1, forced expiratory volume in 1 s; FEF(25–75), forced expiratory flow between 25% and 75% of the vital capacity; FVC, forced vital capacity; PBF, pulmonary blood flow; SpO2, oxygen saturation by pulse oximetry; TLC, total lung capacity.