Cardiovascular autonomic function testing under non‐standardised and standardised conditions in cardiovascular patients with type‐2 diabetes mellitus1. (May 2014) - Keet, S. W. M.
Summary Autonomic function tests require standardised test conditions. We compared testing under non‐standardised and standardised conditions and investigated the agreement between heart and pulse rate variability in 30 subjects with diabetes mellitus. Deep breathing, Valsalva manoeuvre and quick standing tests showed non‐standardised reproducibility intraclass correlations (95% CI) of 0.96 (0.82–0.99), 0.96 (0.81–0.99) and 0.75 (−0.98 to 0.94), respectively. Intraclass correlations for sustained handgrip and quick standing were poor. Heart and pulse rate variability showed high‐frequency band intraclass correlations (95% CI) of 0.65 (−0.07 to 0.89) and 0.47 (−0.88 to 0.85) for the very low‐frequency band, respectively, 0.68 (0.00−0.90) and 0.70 (−0.09 to 0.91) for the low‐frequency band, and 0.86 (0.57−0.95) and 0.82 (0.39−0.95) for the high‐frequency band. Reproducibility under standardised conditions was comparable. The mean difference (95% limits of agreement) between heart and pulse rate variability was 0.99 (0.80−1.22) for very low frequency, 1.03 (0.88−1.21) for low frequency and 1.35 (0.84−2.16) for high frequency, with a Spearman's correlation coefficient of 1.00, 0.99 and 0.98, respectively. We demonstrated a high agreement between heart and pulse rate variability and acceptable reproducibility with most autonomic function tests, heart and pulse rate variability.