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Relationship between changes in pulmonary V˙O2 kinetics and autonomic regulation of blood flow

Melitta McNarry Orcid Logo, M. I. C. Kingsley, Michael Lewis

Scandinavian Journal of Medicine & Science in Sports, Volume: 24, Issue: 4, Pages: 613 - 621

Swansea University Authors: Melitta McNarry Orcid Logo, Michael Lewis

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DOI (Published version): 10.1111/sms.12041

Abstract

Various regulatory mechanisms of pulmonary oxygen uptake () kinetics have been postulated. The purpose of this study was to investigate the relationship between vagal withdrawal, measured using RMSSDRR, the root mean square of successive differences in cardiac interval (RR) kinetics, a mediator of o...

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Published in: Scandinavian Journal of Medicine & Science in Sports
ISSN: 0905-7188
Published: Wiley 2014
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URI: https://cronfa.swan.ac.uk/Record/cronfa14731
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Abstract: Various regulatory mechanisms of pulmonary oxygen uptake () kinetics have been postulated. The purpose of this study was to investigate the relationship between vagal withdrawal, measured using RMSSDRR, the root mean square of successive differences in cardiac interval (RR) kinetics, a mediator of oxygen delivery, and kinetics. Forty-nine healthy adults (23 ± 3 years; 72 ± 13 kg; 1.80 ± 0.08 m) performed multiple repeat transitions to moderate- and heavy-intensity exercise. Electrocardiography, impedance cardiography, and pulmonary gas exchange parameters were measured throughout; time domain measures of heart rate variability were subsequently derived. The parameters describing the dynamic response of , cardiac output () and RMSSDRR were determined using a mono-exponential model. During heavy-intensity exercise, the phase II τ of was significantly correlated with the τ of RR (r = 0.36, P < 0.05), Q (r = 0.67, P < 0.05), and RMSSDRR (r = 0.38, P < 0.05). The τ describing the rise in Q explained 47% of the variation in τ, with 30% of the rate of this rise in Q explained by the τ of RR and RMSSDRR. No relationship was evident between kinetics and those of Q, RR, or RMSSDRR during moderate exercise. Vagal withdrawal kinetics support the concept of a centrally mediated oxygen delivery limitation partly regulating kinetics during heavy-, but not moderate-, intensity exercise.
Keywords: heart rate variability; kinetics;oxygen delivery;cardiac output
College: Faculty of Science and Engineering
Issue: 4
Start Page: 613
End Page: 621