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Randomized Controlled Trial
. 2021 May 31;18(11):5934.
doi: 10.3390/ijerph18115934.

Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

Oriol Abellán-Aynés  1   2 , Pedro Manonelles  2 , Fernando Alacid  3
Affiliations
Randomized Controlled Trial

Cardiac Parasympathetic Withdrawal and Sympathetic Activity: Effect of Heat Exposure on Heart Rate Variability

Oriol Abellán-Aynés et al. Int J Environ Res Public Health. .

Abstract

(1) Background: Research on heart rate variability has increased in recent years and the temperature has not been controlled in some studies assessing repeated measurements. This study aimed to analyze how heart rate variability may change based on environmental temperature during measurement depending on parasympathetic and sympathetic activity variations. (2) Methods: A total of 22 volunteers participated in this study divided into an experimental (n = 12) and control group (n = 10). Each participant was assessed randomly under two different environmental conditions for the experimental group (19 °C and 35 °C) and two identical environmental conditions for the control group (19 °C). During the procedure, heart rate variability measurements were carried out for 10 min. (3) Results: Significantly changes were observed for time and frequency domains as well as Poincaré plot variables after heat exposure (p < 0.05). These findings were not observed in the control group, whose conditions between measurements did not change. (4) Conclusions: The reduction of heart rate variability due to exposure to hot conditions appears to be produced mostly by a parasympathetic withdrawal rather than a sympathetic activation. Therefore, if consecutive measurements have to be carried out, these should always be done under the same temperature conditions.

Keywords: autonomic; cold; heat; parasympathetic; sympathetic.

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Conflict of interest statement

The authors declare no conflict of interest.

References

    1. Horn E., Lee S. Electronic evaluations of the fetal heart rate patterns preceding fetal death: Further observation. Am. J. Obster. Gynecol. 1965;87:824–826.
    1. Pomeranz B., Macaulay R., Caudill M.A., Kutz I., Adam D., Gordon D., Kilborn K.M., Barger A.C., Shannon D.C., Cohen R.J., et al. Assessment of autonomic function in humans by heart rate spectral analysis. Am. J. Physiol. Heart Circ. 1985;248:H151–H153. doi: 10.1152/ajpheart.1985.248.1.H151. - DOI - PubMed
    1. Pagani M., Lombardi F., Guzzetti S., Rimoldi O., Furlan R., Pizzinelli P., Sandrone G., Malfatto G., Dell’Orto S., Piccaluga E. Power spectral analysis of heart rate and arterial pressure variabilities as a marker of sympatho-vagal interaction in man and conscious dog. Circ. Res. 1986;59:178–193. doi: 10.1161/01.RES.59.2.178. - DOI - PubMed
    1. Furlan R., Guzzetti S., Crivellaro W., Dassi S., Tinelli M., Baselli G., Cerutti S., Lombardi F., Pagani M., Malliani A. Continuous 24-hour assessment of the neural regulation of systemic arterial pressure and RR variabilities in ambulant subjects. Circulation. 1990;81:537–547. doi: 10.1161/01.CIR.81.2.537. - DOI - PubMed
    1. Kleiger R.E., Miller J., Bigger J., Moss A.J. Decreased heart rate variability and its association with increased mortality after acute myocardial infarction. Am. J. Cardiol. 1987;59:256–262. doi: 10.1016/0002-9149(87)90795-8. - DOI - PubMed

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