Table 4.
Night 3 (post-REM deprivation recovery) heart rate variability (HRV) measures for subjects with and without frequent nightmares
| Nightmare (N = 14) |
Control (N = 8) |
Group comparisons (P)† |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Time domain | REM | St 2 | Awake | REM | St 2 | Awake | REM | St 2 | Awake | |
| HR | M | 65.6 | 62.6 | 67.1 | 62.8 | 59.9 | 65.2 | ns | ns | ns |
| SD | 11.5 | 11.4 | 11.0 | 8.3 | 6.4 | 7.5 | ||||
| SDNNa | M | 68.6 | 60.4 | 46.8 | 69.6 | 64.2 | 57.8 | ns | ns | ns |
| SD | 28.7 | 32.1 | 23.5 | 23.9 | 27.4 | 21.9 | ||||
| pNN50b | M | 10.6 | 12.5 | 10.1 | 16.6 | 18.5 | 18.9 | ns | ns | 0.053 |
| SD | 7.7 | 9.2 | 9.4 | 8.5 | 9.1 | 10.2 | ||||
|
Frequency domain: Absolute | ||||||||||
| VLF | M | 1104.9 | 874.0 | 387.5 | 1052.6 | 611.7 | 639.0 | ns | ns | ns |
| SD | 1181.8 | 750.6 | 387.5 | 632.7 | 303.2 | 417.0 | ||||
| LF | M | 1885.0 | 1563.8 | 590.3 | 1377.5 | 1405.2 | 497.7 | ns | ns | ns |
| SD | 1438.3 | 1477.0 | 601.6 | 902.9 | 1252.3 | 217.1 | ||||
| HF | M | 1410.6 | 1690.6 | 1189.8 | 2030.4 | 2446.7 | 2294.3 | ns | ns | ns |
| SD | 1822.2 | 2286.1 | 1552.9 | 2084.1 | 2900.1 | 2806.5 | ||||
|
Frequency domain: Normalized | ||||||||||
| LFnuc | M | 57.2 | 45.1 | 39.2 | 39.5 | 32.7 | 24.1 | 0.0005 | 0.016 | 0.052 |
| SD | 11.1 | 10.2 | 17.7 | 6.3 | 11.5 | 14.1 | ||||
| HFnuc | M | 34.5 | 46.5 | 52.8 | 51.9 | 58.0 | 68.1 | 0.001 | 0.023 | 0.063 |
| SD | 11.9 | 9.7 | 18.6 | 7.6 | 11.9 | 15.3 | ||||
| LF/HF | M | 2.8 | 1.5 | 1.6 | 1.0 | 0.9 | 0.5 | 0.006 | ns | ns |
| SD | 1.5 | 0.8 | 2.4 | 0.4 | 0.9 | 0.4 | ||||
†
2-tailed univariate F-tests, P-values >.08 not displayed;
a
SDNN = standard deviation of R-R intervals;
b
pNN50 = proportion of R-R intervals differing from preceding interval by ± 50msec;
c
Normalized values calculated as a proportion of total power minus VLF