Table 2

Heart rate variability indices in patients referred to spine surgery and controls during 5 minutes of supine and standing conditions
Supine Standing
Patients Controls Mean difference (95% CI for difference) Adj. P-value Patients Controls Mean difference (95% CI for difference) Adj. P-value
HR, bpm 69 ± 13 65 ± 10 3 (0 – 6 ) 0.051 85 ± 14 78 ± 13 7 (3 – 10) <0.0001
SDNN, ms 45 ± 28 48 ± 24 2 (−5 – 9) 0.598 51 ± 22 61 ± 27 −6 (−12 – 0) 0.065
HF power, ln ms2 5.6 ± 1.4 6.0 ± 1.3 −0.2 (−0.5 – 0.2) 0.356 4.5 ± 1.2 5.1 ± 1.2 −0.4 (−0.7 – -0.1) 0.011
LF power, ln ms2 6.0 ± 1.1 6.1 ± 1.0 −0.1 (−0.4 – 0.2) 0.404 6.3 ± 1.1 6.6 ± 0.9 −0.2 (−0.5 – 0.1) 0.074
LF-to-HF ratio 2.0 ± 1.7 1.9 ± 2.3 −0.3 (−0.8 – 0.2) 0.205 7.9 ± 6.4 5.8 ± 5.2 1.0 (−0.4 – 2.5) 0.159
SD1, ms 23 ± 15 28 ± 21 −2 (−6 – 3) 0.443 13 ± 7 18 ± 12 −4 (−6 – -1) 0.002
α1 1.09 ± 0.23 1.01 ± 0.29 0.03 (−0.03 – 0.10) 0.304 1.58 ± 0.22 1.49 ± 0.24 0.73 (0.02 – 0.13) 0.012

Values are means ± SD. Mean differences and 95% confidence intervals (CI) for differences between groups are given after adjustment for gender, BMI, smoking status and high LTPA.

HR = heart rate, SDNN = standard deviation of all R-R intervals, HF = high frequency, LF = low frequency, SD1 = beat to beat R-R interval fluctuation, α1 = short-term fractal scaling exponent.

Södervall et al.

Södervall et al. BMC Musculoskeletal Disorders 2013 14:149   doi:10.1186/1471-2474-14-149

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