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. 2020 Jul 3:11:743.
doi: 10.3389/fphys.2020.00743. eCollection 2020.

Association Between Heart Rate Variability and Decompression-Induced Physiological Stress

Sergio Rhein Schirato  1 , Ingrid El-Dash  1 , Vivian El-Dash  1 , Bruna Bizzarro  2 , Alessandro Marroni  3 , Massimo Pieri  3 , Danilo Cialoni  3   4 , José Guilherme Chaui-Berlinck  1
Affiliations

Association Between Heart Rate Variability and Decompression-Induced Physiological Stress

Sergio Rhein Schirato et al. Front Physiol. .

Abstract

The purpose of this study was to analyze the correlation between decompression-related physiological stress markers, given by inflammatory processes and immune system activation and changes in Heart Rate Variability, evaluating whether Heart Rate Variability can be used to estimate the physiological stress caused by the exposure to hyperbaric environments and subsequent decompression. A total of 28 volunteers participated in the experimental protocol. Electrocardiograms were performed; blood samples were obtained for the quantification of red cells, hemoglobin, hematocrit, neutrophils, lymphocytes, platelets, aspartate transaminase (AST), alanine aminotransferase (ALT), and for immunophenotyping and microparticles (MP) research through Flow Cytometry, before and after each experimental protocol from each volunteer. Also, myeloperoxidase (MPO) expression and microparticles (MPs) deriving from platelets, neutrophils and endothelial cells were quantified. Negative associations between the standard deviation of normal-to-normal intervals (SDNN) in the time domain, the High Frequency in the frequency domain and the total number of circulating microparticles was observed (p-value = 0.03 and p-value = 0.02, respectively). The pre and post exposure ratio of variation in the number of circulating microparticles was negatively correlated with SDNN (p-value = 0.01). Additionally, a model based on the utilization of Radial Basis Function Neural Networks (RBF-NN) was created and was able to predict the SDNN ratio of variation based on the variation of specific inflammatory markers (RMSE = 0.06).

Keywords: decompression; decompression profiles; decompression sickness; endothelial function; heart rate variability; hyperbaric environments; immune system; inflammation.

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Figures

FIGURE 1
FIGURE 1
Experimental design flow chart.
FIGURE 2
FIGURE 2
Pre dive and post dive numbers of circulating microparticles.
FIGURE 3
FIGURE 3
Observed and calculated SDNN Ratio based on the variation of CD16(%), CD66b (MFI), MPO(%), MPO (MFI), Annexin +, MP CD66b +, MP CD31 + and MP CD41 +. It is important to note that Training Accuracy and Validation Accuracy are the same, due to the fact that the model is being applied on the training set (in-sample validation). This test was done to evaluate how effective the algorithm is in reproducing the data used for calibration.
FIGURE 4
FIGURE 4
Observed and predicted SDNN Ratio based on the variation of CD16(%), CD66b (MFI), MPO(%), MPO (MFI), Annexin +, CD66b +, CD31 + and CD41 +. Application of the second model on an out-of-sample data set.
FIGURE 5
FIGURE 5
Training and validation error distribution produced by the 500 models created based on the resampled data.
Appendix 1
Appendix 1
Flow cytometry gates definition Immunophenotyping.
Appendix 2
Appendix 2
Flow cytometry gates definition for Microparticles analysis.
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References

    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. 10.1007/s11517-006-0119-0 - DOI - PubMed
    1. Agelink M. W., Majewski T. B., Andrich J., Mueck-Weymann M. (2002). Short-term effects of intravenous benzodiazepines on autonomic neurocardiac regulation in humans: A comparison between midazolam, diazepam, and lorazepam. Crit. Care Med. 30 997–1006. 10.1097/00003246-200205000-00008 - DOI - PubMed
    1. American T. N. (1996). Task force of the european society of cardiology and the north american society of pacing and electrophysiology. heart rate variability: standards of measurement, physiological interpretation, and clinical use. Eur. Heart J. 17 354–381. 10.1161/01.CIR.93.5.1043 - DOI - PubMed
    1. Appel M. L., Berger R. D., Saul J. P., Smith J. M., Cohen R. J. (1989). Beat to beat variability in cardiovascular variables: noise or music? J. Am. Coll. Cardiol. 14 1139–1148. 10.1016/0735-1097(89)90408-7 - DOI - PubMed
    1. Bai Y., Mahon R. T., White J. C., Brink P. R., Chon K. H. (2009). Impairment of the autonomic nervous function during decompression sickness in swine. J. Appl. Physiol. 106 1004–1009. 10.1152/japplphysiol.91246.2008 - DOI - PubMed