Key result
Head up tilt and atropine administration significantly reduced the correlation dimension of heart rate variability compared to supine rest (5.9 and 4.2 vs 7.8, respectively; P<0.01 for both).
Why the study?
Do autonomic perturbations alter the correlation dimension of heart rate variability in healthy subjects?
Observational (n=12)
Do autonomic perturbations alter the correlation dimension of heart rate variability in healthy subjects?
p-value: p=<0.01
The correlation dimension of heart rate variability is sensitive to autonomic perturbations, suggesting it can accurately measure cardiac autonomic nervous system activity.
Correlation dimension of HRV may track autonomic perturbations in healthy subjects; leaves open its diagnostic utility in clinical populations.
Background: Linear methods of time series analysis such as summary statistics and frequency‐domain parameters have been used to measure heart rate variability (HRV). More recently, nonlinear methods including the correlation dimension (CDim) have been used to evaluate HRV. The aim of this study was to examine the effect of autonomic perturbations on the CDim. Methods: The CDim was calculated from 2000 data points (RR intervals) collected over a relatively short period of time (20–40 min) in 12 healthy subjects aged between 20 and 40 years (mean 30 ± 2 years) during: (a) supine rest; (b) head up tilt (sympathetic activation, parasympathetic nervous system activity withdrawal); (c) intravenous infusion of atropine (parasympathetic nervous system activity withdrawal); and (d) following overnight administration of low dose transdermal scopolamine (parasympathetic nervous system augmentation. Results: The CDim was determined at rest (7.8 ± 0.3) and found to be significantly reduced during tilt (5.9 ± 0.4, P < 0.01) and atropine administration (4.2 ± 0.4, P < 0.01) and possibly increased by scopolamine (8.3 ± 0.5, NS). Conclusions: The changes following these interventions suggest that CDim can accurately measure cardiac autonomic nervous system activity.
No takes yet. Share an insight, caveat, or question.
Kamen et al. (1997) conducted an observational in Healthy subjects (n=12). Head up tilt, intravenous atropine, and transdermal scopolamine vs. Supine rest was evaluated on Correlation dimension (CDim) of heart rate variability (p=<0.01). Head up tilt and atropine administration significantly reduced the correlation dimension of heart rate variability compared to supine rest (5.9 and 4.2 vs 7.8, respectively; P<0.01 for both).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: