Table 3.
The ‘sinus’ and ‘absolute’ beat-to-beat variability and instability of the RR interval in anaesthetized rabbits
| n | MeanRR | SD | RMS | RMSSD | SDSD | TI | STI | ||
|---|---|---|---|---|---|---|---|---|---|
| Sinus | TdP− | ||||||||
| Baseline | 10 | 221 ± 8 | 1.6 ± 0.1 | 221 ± 8 | 1.8 ± 0.1 | 1.9 ± 0.1 | 1.9 ± 0.2 | 1.0 ± 0.1 | |
| Phe | 8 | 259 ± 14‡ | 2.3 ± 0.5 | 259 ± 14‡ | 2.2 ± 0.2 | 2.3 ± 0.2 | 2.7 ± 0.6 | 1.0 ± 0.1 | |
| Dof | 8 | 264 ± 15‡ | 2.3 ± 0.4 | 264 ± 15‡ | 2.4 ± 0.4 | 2.4 ± 0.4 | 2.8 ± 0.6 | 1.2 ± 0.2 | |
| TdP+ | |||||||||
| Baseline | 20 | 215 ± 5 | 1.8 ± 0.2 | 215 ± 2 | 1.8 ± 0.1 | 1.8 ± 0.1 | 2.1 ± 0.2 | 0.9 ± 0.1 | |
| Phe | 13 | 265 ± 11‡ | 2.8 ± 0.5 | 265 ± 11‡ | 3.0 ± 0.7 | 3.1 ± 0.7 | 3.4 ± 0.7 | 1.7 ± 0.5 | |
| Dof | 12 | 270 ± 11‡ | 3.1 ± 0.5‡ | 270 ± 11‡ | 3.6 ± 0.7‡ | 3.6 ± 0.7‡ | 4.0 ± 0.8‡ | 1.9 ± 0.5‡ | |
| Absolute | TdP− | ||||||||
| Phe | 10 | 257 ± 11 | 13.4 ± 7.2 | 258 ± 11 | 19.9 ± 2.6 | 20.2 ± 12 | 11.3 ± 5.8 | 7.2 ± 5.4 | |
| Dof | 10 | 259 ± 12 | 18.1 ± 7.9 | 260 ± 12 | 31.8 ± 14.2 | 32.2 ± 14 | 21.5 ± 10.8 | 17.4 ± 8.6 | |
| Bef TdP | 10 | 273 ± 11 | 46.9 ± 9.5#† | 279 ± 12#† | 81.3 ± 17.4# | 82.3 ± 17.7#† | 60.3 ± 13.5# | 50.1 ± 12.8#† | |
| TdP+ | |||||||||
| Phe | 20 | 262 ± 7 | 22.6 ± 4.9 | 263 ± 7 | 39.5 ± 9.2 | 40.1 ± 9.4 | 24.5 ± 6.1 | 22.6 ± 6.2 | |
| Dof | 20 | 265 ± 7 | 38.5 ± 5.6# | 269 ± 7 | 67.9 ± 10.2# | 68.8 ± 10.3# | 44.3 ± 7.8*# | 39.8 ± 7.5*# | |
| Bef TdP | 20 | 291 ± 17#† | 71.5 ± 5.9*#† | 300 ± 17#† | 106.1 ± 9.4#† | 107.4 ± 9.5#† | 76.9 ± 8.4#† | 53.0 ± 6.9#† | |
P < 0.05 versus ‘TdP−’ group, Kruskal–Wallis test.
P < 0.05 versus baseline.
P < 0.05 versus Phe.
P < 0.05 versus Dof, Wilcoxon test.
Sinus, the beat-to-beat variability and instability of the RR interval when measured in sinus rhythm; Absolute, the beat-to-beat variability and instability of the RR interval when arrhythmias were involved in the measurement; n, number of animals in which the RR variability and instability were determined (sinus variability and instability were determined only when there was sinus rhythm at the time point of the measurement); MeanRR, the mean of the measured 40 consecutive RR intervals (ms); SD, the standard deviation of the measured 40 consecutive RR intervals (ms); RMS, the root mean square of the RR intervals (ms); RMSSD, the root mean square of the successive differences of the RR intervals (ms); SDSD, standard deviation of successive differences of the RR intervals (ms); TI, total instability of the RR intervals (ms); STI, short-term instability of the RR intervals (ms).