Time and frequency domain measurements of the 24 h RR interval variability
| Atenolol | Metoprolol CR | |
|---|---|---|
| RR means (ms) | 1076 (32)1-150 | 1006 (26) |
| SDNN (ms) | 155 (8) | 159 (9) |
| ULF (ms2/Hz) | 23 006 (2625) | 24 855 (3035) |
| 1n ULF | 9.85 (0.10) | 9.89 (0.11) |
| VLF (ms2/Hz) | 2153 (313) | 1858 (199) |
| 1n VLF | 7.35 (0.14) | 7.29 (0.13) |
| LF (ms2/Hz) | 985 (131) | 832 (116) |
| 1n LF | 6.60 (0.14)1-150 | 6.45 (0.14) |
| HF (ms2/Hz) | 639 (90) | 471 (64) |
| 1nHF | 6.13 (0.14)1-150 | 5.83 (0.14) |
| LF/HF ratio | 1.89 (0.17) | 2.30 (0.28) |
| 1n LF/HF | 0.47 (0.11) | 0.62 (0.12) |
Values are means (SEM).
↵1-150 p < 0.05 between treatments.
SDNN, standard deviation of all normal RR values; ULF, ultra low frequency power; VLF, very low frequency power; LF, low frequency power; HF, high frequency power; 1n, natural logarithm.