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. 2022 Feb 28:13:829887.
doi: 10.3389/fphys.2022.829887. eCollection 2022.

Reliability of Symbolic Analysis of Heart Rate Variability and Its Changes During Sympathetic Stimulation in Elite Modern Pentathlon Athletes: A Pilot Study

Jakub S Gąsior  1 , Maciej Rosoł  2 , Marcel Młyńczak  2 , Andrew A Flatt  3 , Bartosz Hoffmann  4 , Rafał Baranowski  5 , Bożena Werner  1
Affiliations

Reliability of Symbolic Analysis of Heart Rate Variability and Its Changes During Sympathetic Stimulation in Elite Modern Pentathlon Athletes: A Pilot Study

Jakub S Gąsior et al. Front Physiol. .

Abstract

Background and purpose: Most studies on heart rate variability (HRV) in professional athletes concerned linear, time-, and frequency-domain indices, and there is lack of studies on non-linear parameters in this group. The study aimed to determine the inter-day reliability, and group-related and individual changes of short-term symbolic dynamics (SymDyn) measures during sympathetic nervous system activity (SNSa) stimulation among elite modern pentathletes.

Methods: Short-term electrocardiographic recordings were performed in stable measurement conditions with a 7-day interval between tests. SNSa stimulation via isometric handgrip strength test was conducted on the second day of study. The occurrence rate of patterns without variations (0V), with one variation (1V), two like (2LV), and two unlike variations (2UV) obtained using three approaches (the Max-min, the σ, and the Equal-probability methods) were analyzed. Relative and absolute reliability were evaluated.

Results: All SymDyn indices obtained using the Max-min method, 0V, and 2UV obtained using the σ method, 2UV obtained using the Equal-probability method presented acceptable inter-day reliability (the intraclass correlation coefficient between .91 and .99, Cohen's d between -.08 and .10, the within-subject coefficient of variation between 4% and 22%). 2LV, 2UV, and 0V obtained using the Max-min and σ methods significantly decreased and increased, respectively, during SNSa stimulation-such changes were noted for all athletes. There was no significant association between differences in SymDyn parameters and respiratory rate in stable conditions and while comparing stable conditions and SNSa stimulation.

Conclusion: SymDyn indices may be used as reliable non-respiratory-associated parameters in laboratory settings to detect autonomic nervous system (ANS) activity modulations in elite endurance athletes. These findings provide a potential solution for addressing the confounding influence of respiration frequency on HRV-derived inferences of cardiac autonomic function. For this reason, SymDyn may prove to be preferable for field-based monitoring where measurements are unsupervised.

Keywords: athletes; heart rate variability; modern pentathlon athletes; non-linear; symbolic dynamics.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Study protocol.
Figure 2
Figure 2
Bland–Altman plots for SymDyn indices: 0V, 1V, 2LV, and 2UV (Test and Retest): (A) the Max–min method, (B) the σ-method. The black dashed line indicates the mean difference, the grey dashed lines are the limits of agreement (±1.96 SD), and the green lines are the maximum allowed difference.
Figure 3
Figure 3
Bland–Altman plots for SymDyn indices: 0V, 1V, 2LV, and 2UV (Test and Retest): the Equal-probability method (A) q = 6, (B) q = 4. The black dashed line indicates the mean difference, the grey dashed lines are the limits of agreement (±1.96 SD), and the green lines are the maximum allowed difference.
Figure 4
Figure 4
Bland–Altman plots for SymDyn indices 0V, 1V, 2LV, and 2UV (Retest and sympathetic nervous system activity—SNSa stimulation): (A) the Max–min method, (B) the σ-method. The black dashed line indicates the mean difference, the grey dashed lines are the limits of agreement (±1.96 SD), and the green lines are the maximum allowed difference.
Figure 5
Figure 5
Bland–Altman plots for SymDyn indices 0V, 1V, 2LV, and 2UV (Retest and SNSa stimulation): the Equal-probability method (A) q = 6, (B) q = 4. The black dashed line indicates the mean difference, the grey dashed lines are the limits of agreement (±1.96 SD), and the green lines are the maximum allowed difference.
Figure 6
Figure 6
Correlation between retest–test differences in SymDyn indices and differences in respiratory rate (RespRate): (A) the Max–min method, (B) the σ-method.
Figure 7
Figure 7
Correlation between retest–test differences in SymDyn indices and differences in respiratory rate (RespRate): the Equal-probability method (A) q = 6, (B) q = 4.
Figure 8
Figure 8
Correlation between SNSa stimulation–retest differences in SymDyn indices and differences in respiratory rate (RespRate): (A) the Max–min method, (B) the σ-method.
Figure 9
Figure 9
Correlation between SNSa stimulation–retest differences in SymDyn indices and differences in respiratory rate (RespRate): the Equal-probability method (A) q = 6, (B) q = 4.
Figure 10
Figure 10
Individual changes in SymDyn indices between Test, Retest, and SNSa stimulation: (A) the Max–min method, (B) σ-method.
Figure 11
Figure 11
Individual changes in SymDyn indices between Test, Retest, and SNSa stimulation: the Equal-probability method (A) q = 6, (B) q = 4.
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References

    1. Abu-Arafeh A., Jordan H., Drummond G. (2016). Reporting of method comparison studies: a review of advice, an assessment of current practice, and specific suggestions for future reports. Br. J. Anaesth. 117, 569–575. doi: 10.1093/bja/aew320, PMID: - DOI - PubMed
    1. Acharya U. R., Joseph K. P., Kannathal N., Lim C. M., Suri J. S. (2006). Heart rate variability: a review. Med. Biol. Eng. Comput. 44, 1031–1051. doi: 10.1007/s11517-006-0119-0 - DOI - PubMed
    1. Al Haddad H., Laursen P. B., Chollet D., Ahmaidi S., Buchheit M. (2011). Reliability of resting and postexercise heart rate measures. Int. J. Sports Med. 32, 598–605. doi: 10.1055/s-0031-1275356, PMID: - DOI - PubMed
    1. Araújo C. G., Scharhag J. (2016). Athlete: a working definition for medical and health sciences research. Scand. J. Med. Sci. Sports 26, 4–7. doi: 10.1111/sms.12632, PMID: - DOI - PubMed
    1. Atkinson G., Nevill A. M. (1998). Statistical methods for assessing measurement error (reliability) in variables relevant to sports medicine. Sports Med. 26, 217–238. doi: 10.2165/00007256-199826040-00002, PMID: - DOI - PubMed

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