Table 2.
I/E ratio, IE differences, and heart-rate variability during respiratory sinusal arrhythmia maneuver for the studied groups.
| COPD (n = 10) | Control (n = 9) | |
|---|---|---|
| Time domain | ||
| E/I ratio | 1.1 ± 0.06 | 1.2 ± 0.1* |
| ΔIE | 7.0 ± 3.5 | 12.7 ± 4.2* |
| RMSSD | 18.3 ± 15.6 | 43.5 ± 27.9* |
| SDNN | 32.1 ± 21.2 | 63.8 ± 29.1* |
| Frequency domain | ||
| LFab | 1052.7 ± 1538.3 | 3551.2 ± 3581.2* |
| HFab | 93.9 ± 153.8 | 626.8 ± 906.8* |
| LFun | 0.9 ± 0.03 | 0.8 ± 0.07 |
| HFun | 0.1 ± 0.03 | 0.2 ± 0.07 |
| LF/HF | 15.9 ± 15.3 | 11.3 ± 7.5 |
Values are means ± SD. COPD: chronic obstructive pulmonary disease; E/I ratio: expiratory/inspiratory ratio; ΔIE: inspiratory-expiratory differences; RMSSD: the square root of the sum of the squares of differences between adjacent NN intervals; SDNN: the standard deviation of NN intervals; LFab: low frequency in absolutes values; HFab: high frequency in absolutes values; LFun: low frequency in normalized units; HFun: high frequency in normalized units;
*
p<0.05: COPD vs. Control (unpaired Student’s t-test).