Heart rate variability (HRV) reflects dynamic variation in sympathetic and
parasympathetic nervous system (SNS and PNS) activity. The parasympathetic
vagus nerve is responsible for HRV between 0.12 and 0.4 Hz, which is thought to
index the capacity for effective coping, and is linked to physical and emotional
well-being. Yogic breathing to increase vagal activity is often paced below 0.12
Hz (< 7.2 breaths per minute (BrPM)), where its impact HRV can be due to both
sympathetic and parasympathetic mechanisms. Five healthy volunteers
completed three pharmacological blockade sessions (placebo, sympathetic
blockade with Esmolol, and parasympathetic blockade with Glycopyrrolate) about
48 hours apart, and during each session completed 11 Sudarshan Kriya Yogic
breathing exercises at 4-9 BrPM. HRV was the lowest under Glycopyrrolate (p <
0.001), and there was no significant difference between placebo and sympathetic
blockade with Esmolol. In addition, the spectral power of specific HRV
frequencies was greatest at similar frequencies of breathing, a pattern prevented
only by Glycopyrrolate. These findings suggest that heart rate is vagally
influenced at all breathing rates, and that the SNS is not the mechanism by which
slow breathing increases HRV.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/614163 |
| Date | January 2016 |
| Creators | SANOVA, ANNA ANDREA |
| Contributors | Allen, John J.B. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Electronic Thesis |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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