Cardiac frequency variability during baroreflex sensitivity measurement in chronic obstructive pulmonary disease (COPD) patients before and after rehabilitation programme and controls
| COPD patients | Controls | ||
| Before programme | After programme | ||
| Spontaneous breathing | |||
| Ptot ms2×10−6 | 359±297* | 266±202* | 557±485 |
| LF ms2·Hz−1×10−6 | 80.2±58.6 | 69.9±50.4 | 116.5±15.9 |
| HF ms2·Hz−1×10−6 | 52.5±67.3 | 48.5±51.7 | 63.7±83.2 |
| LFnu ms2·Hz−1×10−6 | 54.8±25.9 | 56.5±24.9 | 60.1±19.4 |
| HFnu ms2·Hz−1×10−6 | 30.8±18.4 | 28.8±17.8 | 32.1±17.8 |
| LF/HF | 3.5±4.0 | 3.7±4.7 | 2.6±1.9 |
| Head-up tilt | |||
| Ptot ms2×10−6 | 214±196* | 234±180* | 419±262 |
| LF ms2·Hz−1×10−6 | 55.4±66.7 | 56.7±36.5 | 110.7±98.4 |
| HF ms2·Hz−1×10−6 | 28.8±30.4 | 35.4±39.5 | 35.3±31.4 |
| LFnu ms2·Hz−1×10−6 | 53.6±23.1 | 55.4±25.5 | 68.7±15.8 |
| HFnu ms2·Hz−1×10−6 | 26.3±15.5 | 27.9±16.1 | 23.9±11.1 |
| LF/HF | 3.0±2.7 | 3.7±4.7 | 4.1±3.1 |
Ptot: total frequency power
LF: low-frequency peak
HF: high-frequency peak
LFnu: normalised LF
HFnu: normalised HF
*: p<0.05 versus controls