Controlled breathing protocols probe human autonomic cardiovascular rhythms
- 1 February 1998
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Heart and Circulatory Physiology
- Vol. 274 (2), H709-H718
- https://doi.org/10.1152/ajpheart.1998.274.2.h709
Abstract
The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0.1, and 0.05 Hz for 2 min each); 3) stepwise frequency breathing as above, but with prescribed tidal volumes; 4) random-frequency breathing (∼0.5–0.05 Hz) for 6 min; and 5) fixed-frequency breathing (0.25 Hz) for 5 min. During stepwise breathing, R-R interval and arterial pressure spectral power increased as breathing frequency decreased. Control of inspired volume reduced R-R interval spectral power during 0.1 Hz breathing ( P < 0.05). Stepwise and random-breathing protocols yielded comparable coherence and transfer functions between respiration and R-R intervals and systolic pressure and R-R intervals. Random- and fixed-frequency breathing reduced end-tidal CO2modestly ( P < 0.05). Our data suggest that stringent tidal volume control attenuates low-frequency R-R interval oscillations and that fixed- and random-rate breathing may decrease CO2 chemoreceptor stimulation. We conclude that autonomic rhythms measured during different breathing protocols have much in common but that a stepwise protocol without stringent control of inspired volume may allow for the most efficient assessment of short-term respiratory-mediated autonomic oscillations.Keywords
This publication has 15 references indexed in Scilit:
- Human autonomic rhythms: vagal cardiac mechanisms in tetraplegic subjects.The Journal of Physiology, 1994
- Important influence of respiration on human R-R interval power spectra is largely ignoredJournal of Applied Physiology, 1993
- Cardiovascular neural regulation explored in the frequency domain.Circulation, 1991
- Assessment of autonomic response by broad-band respirationIEEE Transactions on Biomedical Engineering, 1989
- Respiratory modulation of muscle sympathetic and vagal cardiac outflow in man.The Journal of Physiology, 1985
- Human sinus arrhythmia as an index of vagal cardiac outflowJournal of Applied Physiology, 1983
- Cardiac vagal efferent activity and heart period in the carotid sinus reflexAmerican Journal of Physiology-Legacy Content, 1970
- On the Kolmogorov-Smirnov Test for Normality with Mean and Variance UnknownJournal of the American Statistical Association, 1967
- Respiratory sinus arrhythmia: a frequency dependent phenomenonJournal of Applied Physiology, 1964
- Respiratory sinus arrhythmia: laws derived from computer simulationJournal of Applied Physiology, 1960