Table 3.
Sleep Stage Effects on HRV and QT Variability Measures in OSA Patients
| REM | S2 | SWS | Wake | ANOVA | Sign Post hoc | |
|---|---|---|---|---|---|---|
| Heart rate variability measures | ||||||
| Heart rate | 70 ± 9 | 69 ± 8 | 71 ± 9 | 73 ± 10 | 0.014 | S2vsWake |
| meanNN | 873 ± 111 | 890 ± 109 | 870 ± 120 | 837 ± 123 | 0.014 | S2vsWake |
| sdNN | 64 ± 28 | 48 ± 19 | 55 ± 24 | 55 ± 24 | 0.0014 | S2vsREM, SWSvsREM |
| Rmssd | 52 ± 31 | 44 ± 22 | 40 ± 25 | 47 ± 24 | 0.02 | SWSvsREM |
| logVLF | 3.26 ± 0.32 | 2.81 ± 0.36 | 2.58 ± 0.41 | 3.05 ± 0.39 | <0.0001 | REMvsS2, REMvsSWS, SWSvsWake, S2vsWake |
| logLF | 2.98 ± 0.33 | 2.84 ± 0.34 | 2.60 ± 0.47 | 3.05 ± 0.39 | <0.0001 | REMvsSWS, S2vsSWS, SWSvsWake |
| logHF | 2.52 ± 0.54 | 2.58 ± 0.53 | 2.48 ± 0.64 | 2.49 ± 0.47 | 0.7 | – |
| logLF/logHF | 1.22 ± 0.21 | 1.13 ± 0.15 | 1.10 ± 0.17 | 1.15 ± 0.16 | 0.007 | REMvsSWS |
| QT variability measures | ||||||
| logQTvar | 1.39 ± 0.55 | 1.26 ± 0.53 | 1.38 ± 0.59 | 1.34 ± 0.433 | 0.3 | – |
| QTVi | −1.43 ± 0.51 | −1.34 ± 0.50 | −1.03 ± 0.62 | −1.33 ± 0.43 | <0.0001 | SWSvsREM, SWSvsS2, SWSvsWake |
| QT/RRslope | 0.035 ± 0.023 | 0.024 ± 0.039 | 0.027 ± 0.034 | 0.042 ± 0.017 | 0.03 | S2vsWake |
| QT/RRr2 | 0.21 ± 0.12 | 0.17 ± 0.13 | 0.12 ± 0.12 | 0.18 ± 0.11 | 0.01 | REMvsSWS |
| QT/RRcoherence | 0.43 ± 0.12 | 0.41 ± 0.13 | 0.35 ± 0.14 | 0.37 ± 0.12 | 0.007 | REMvsSWS |
Data presented as mean ± standard deviation; n = 20. The last column shows the sleep stages that were significantly different from each other, using the Tukey multiple comparison post hoc test.