Table 3.
Parameters of heart rate variability during the drug-free and treatment periods
| Drug-free period | Nifedipine CR Treatment period | Difference (95% CI) | Drug-free period | Nifedipine retard Treatment period | Difference (95% CI) | |
|---|---|---|---|---|---|---|
| 24-h | ||||||
| LF, ln (ms2) | 4.74 ± 0.19 | 4.48 ± 0.16 | −0.54, 0.02 | 4.90 ± 0.21 | 4.47 ± 0.17** | −0.67, −0.19 |
| HF, ln (ms2) | 4.21 ± 0.27 | 3.91 ± 0.26 | −0.65, 0.06 | 4.30 ± 0.28 | 3.88 ± 0.16* | −0.77, −0.06 |
| ln (LF/HF) | 0.54 ± 0.14 | 0.57 ± 0.15 | −0.10, 0.16 | 0.61 ± 0.16 | 0.59 ± 0.14 | −0.26, 0.24 |
| Daytime (07.00–21.59 h) | ||||||
| LF, ln (ms2) | 4.50 ± 0.17 | 4.32 ± 0.13 | −0.46, 0.10 | 4.83 ± 0.23 | 4.39 ± 0.18* | −0.69, −0.20 |
| HF, ln (ms2) | 3.75 ± 0.27 | 3.55 ± 0.21 | −0.57, 0.17 | 3.96 ± 0.33 | 3.50 ± 0.20* | −0.88, −0.05 |
| ln (LF/HF) | 0.75 ± 0.14 | 0.77 ± 0.12 | −0.12, 0.16 | 0.87 ± 0.20 | 0.89 ± 0.16 | −0.25, 0.30 |
| Nighttime (22:00–06.59 h) | ||||||
| LF, ln (ms2) | 5.14 ± 0.26 | 4.74 ± 0.22* | −0.76, −0.05 | 5.02 ± 0.20 | 4.61 ± 0.18* | −0.73, −0.09 |
| HF, ln (ms2) | 4.96 ± 0.31 | 4.51 ± 0.35 | −0.88, −0.02 | 4.86 ± 0.24 | 4.53 ± 0.16 | −0.66, 0.00 |
| ln (LF/HF) | 0.19 ± 0.19 | 0.23 ± 0.21 | −0.16, 0.25 | 0.16 ± 0.16 | 0.09 ± 0.16 | −0.34, 0.19 |
LF, Low-frequency component; HF, high-frequency component.
*
P < 0.05;
**
P < 0.01, compared with drug-free period.