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dc.contributor.authorGiles, David
dc.contributor.authorKelly, John
dc.contributor.authorDraper, Nick
dc.date.accessioned2016-11-25T10:07:55Z
dc.date.available2016-11-25T10:07:55Z
dc.date.issued2016
dc.identifier.citationGiles, D. et al (2016) 'Alterations in autonomic cardiac modulation in response to normobaric hypoxia', European Journal of Sport Science, 16 (8):1023en
dc.identifier.issn1746-1391
dc.identifier.doi10.1080/17461391.2016.1207708
dc.identifier.urihttp://hdl.handle.net/10545/621062
dc.description.abstractPurpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% FIO2). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnRMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO2 occurred with reduced FIO2, along with a rise in heart rate (Cohen’s d = 1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% FIO2. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% FIO2) decrease in lnTP (d = 1.84 [1.74–1.94]), and SampEn (d = 0.98 [0.83–1.12]) and an increase in DFA-α1 (d = 0.72 [0.60–0.84]) from normoxia at 9.8% FIO2. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ∼9.8% FIO2 (∼6000 m equiv.), below which significant alterations in autonomic control occur.
dc.language.isoenen
dc.publisherTaylor and Francisen
dc.relation.urlhttps://www.tandfonline.com/doi/full/10.1080/17461391.2016.1207708en
dc.rightsArchived with thanks to European Journal of Sport Scienceen
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en
dc.subjectNormobaric hypoxiaen
dc.subjectAutonomic nervous systemen
dc.subjectHeart rate variabilityen
dc.subjectSample entropyen
dc.titleAlterations in autonomic cardiac modulation in response to normobaric hypoxiaen
dc.typeArticleen
dc.identifier.eissn1536-7290
dc.contributor.departmentUniversity of Derbyen
dc.identifier.journalEuropean Journal of Sport Scienceen
refterms.dateFOA2019-02-28T15:03:41Z
html.description.abstractPurpose: The present study aimed to determine if autonomic cardiac modulation was influenced by acute exposure to normobaric hypoxia. Method: Ten healthy male lowland dwellers completed five block-randomised single-blinded, crossed-over acute exposures to a normobaric hypoxic environment, each separated by 24 hours’ recovery (20.3%, 17.4%, 14.5%, 12.0% and 9.8% FIO2). Supine recordings were made of arterial oxygen saturation and electrocardiogram (ECG). RR intervals from the ECG trace were analysed for time (SDNN, lnRMSSD), frequency (lnVLF, lnLF, lnHF, lnTP, LFnu, and HFnu), and nonlinear (DFA-α1 and SampEn) heart rate variability components. Results: A significant reduction in arterial SaO2 occurred with reduced FIO2, along with a rise in heart rate (Cohen’s d = 1.16, 95% Confidence Interval [2.64–6.46]), significant at 9.8% FIO2. A decrease in autonomic cardiac modulation was also found as shown by a statistically significant (at 9.8% FIO2) decrease in lnTP (d = 1.84 [1.74–1.94]), and SampEn (d = 0.98 [0.83–1.12]) and an increase in DFA-α1 (d = 0.72 [0.60–0.84]) from normoxia at 9.8% FIO2. Conclusion: The decrease in variability indicated a reduction in autonomic cardiac modulation. There appears to be a threshold ∼9.8% FIO2 (∼6000 m equiv.), below which significant alterations in autonomic control occur.


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Archived with thanks to European Journal of Sport Science
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