Relation between baroreflex sensitivity and cardiac vagal tone in humans

1994 ◽  
Vol 266 (1) ◽  
pp. H21-H27 ◽  
Author(s):  
M. Kollai ◽  
G. Jokkel ◽  
I. Bonyhay ◽  
J. Tomcsanyi ◽  
A. Naszlady
Keyword(s):  
Baroreflex Sensitivity ◽  
Regression Line ◽  
Systolic Pressure ◽  
Vagal Tone ◽  
Threshold Level ◽  
Dominant Factor ◽  
Cardiac Vagal Tone ◽  
The Individual ◽  
Method R ◽  
Maximum Threshold

The extent of dependence of cardiac vagal tone on arterial baroreceptor input has been studied in 12 healthy, young adult subjects. Cardiac vagal tone was defined as the chang in R-R interval after complete cholinergic blockade by atropine. Baroreflex sensitivity was determined with the "Oxford-method": R-R interval was regressed against systolic pressure. The interindividual correlation between cardiac vagal tone and baroreflex sensitivity for falling pressures was found to be significant, but not close (R = 0.81, P = 0.002). In each subject, the baroreflex regression line for falling pressures was extrapolated to the post-atropine R-R interval level; 50 mmHg was considered as minimum and 80 mmHg as maximum threshold level for the integrated baroreflex. From the relation between the individual regression lines and the minimum and maximum threshold levels, it was concluded that cardiac vagal tone could be generated by both baroreflex-dependent and -independent mechanisms, the ratio of which varies in different individuals, with the baroreflex-dependent mechanism being the dominant factor.

Heart Rate Variability, Baroreflex Sensitivity, and Cardiac Vagal Tone

1996 ◽  
Vol 91 (s1) ◽  
pp. 113-115
Author(s):  
Cees A. Swenne ◽  
Marianne Bootsma ◽  
Barry W. Hyndman ◽  
Janine Voogd ◽  
Albert V.G. Bruschke
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Baroreflex Sensitivity ◽  
Vagal Tone ◽  
Cardiac Vagal Tone

Evening Binge Alcohol Disrupts Cardiovagal Tone and Baroreflex Function During Polysomnographic Sleep

SLEEP ◽  
2021 ◽  
Author(s):  
Ian M Greenlund ◽  
Jeremy A Bigalke ◽  
Anne L Tikkanen ◽  
John J Durocher ◽  
Carl A Smoot ◽  
...  
Keyword(s):  
Cardiovascular Risk ◽  
Alcohol Consumption ◽  
Binge Drinking ◽  
Baroreflex Sensitivity ◽  
Sleep Stage ◽  
Vagal Tone ◽  
Sleep Stages ◽  
Cardiac Vagal Tone ◽  
Baroreflex Function

Abstract Study Objectives Binge alcohol consumption is associated with increased cardiovascular risk. The effects of evening binge alcohol consumption (i.e., 4-5 beverages within two hours) on the vagal components of HRV and cardiovagal baroreflex sensitivity (cvBRS) during sleep remain largely equivocal. The present study examined the effects of evening binge alcohol consumption on nocturnal cardiac vagal tone and baroreflex sensitivity during stage N2, slow wave (SWS), and rapid eye movement (REM) sleep. We hypothesized that evening binge drinking would reduce HRV and cvBRS in each sleep stage. Methods Following a familiarization night within the laboratory, twenty-three participants were examined following a night of binge alcohol consumption and a fluid control (randomized, crossover design). A quality nocturnal beat-to-beat blood pressure signal was obtained in both conditions in 16 participants (7 men, 9 women; 25±1 years). Results Binge drinking reduced both the high frequency (HF) and time-domain components (i.e., pNN50 and RMSSD) of HRV in stage N2 sleep, SWS, and REM. In addition, cvBRS up-up (vagal activation) was reduced following binge alcohol consumption in stage N2 (21±3 vs. 15±3 ms/mmHg, P=0.035) and REM (15[11-28] vs. 11[9-18] ms/mmHg, P=0.009). Binge alcohol consumption reduced cvBRS down-down (vagal withdrawal) in stage N2 (23±2 vs. 14±2 ms/mmHg, P<0.001), SWS (20[14-30] vs. 14[9-17] ms/mmHg, P=0.022), and REM (14[11-24] vs. 10[7-15] ms/mmHg, P=0.006). Conclusions Evening binge alcohol consumption disrupts cardiac vagal tone and baroreflex function during nearly all sleep stages. These findings provide mechanistic insight into the potential role of binge drinking and alcohol abuse on cardiovascular risk.

scholarly journals Effects of lorazepam on cardiac vagal tone during rest and mental stress: assessment by means of spectral analysis

1994 ◽  
Vol 114 (1) ◽  
pp. 81-89 ◽  
Author(s):  
J. H. M. Tulen ◽  
G. Mulder ◽  
L. Pepplinkhuizen ◽  
A. J. Man in't Veld ◽  
H. G. van Steenis ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Mental Stress ◽  
Vagal Tone ◽  
Cardiac Vagal Tone ◽  
Stress Assessment

scholarly journals Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

2005 ◽  
Vol 5 (3) ◽  
pp. 2897-2945 ◽  
Author(s):  
C. Hak ◽  
I. Pundt ◽  
C. Kern ◽  
U. Platt ◽  
J. Dommen ◽  
...  
Keyword(s):  
Regression Line ◽  
Ambient Air ◽  
Urban Site ◽  
Optical Absorption Spectroscopy ◽  
Measuring Instruments ◽  
Chromatographic Technique ◽  
In Situ Techniques ◽  
Time Period ◽  
The Individual

Abstract. Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interferometry, the fluorimetric Hantzsch reaction technique (five instruments) and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine). White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within ±11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

scholarly journals Structural features of complex hydrochemical systems

2019 ◽  
Vol 127 ◽  
pp. 02029
Author(s):  
Olga Shevtsova
Keyword(s):  
Collective Behavior ◽  
Information Technologies ◽  
System Analysis ◽  
Regression Line ◽  
Mathematical Expression ◽  
Structural Features ◽  
Time Variability ◽  
Hydrochemical Parameters ◽  
Scale Range ◽  
The Individual

The set of non-conservative hydrochemical parameters is considered as a complex system, which displays collective behavior. It is found that the collective behavior is described by the power relation between the time variability (the standard deviations) and the average concentrations of different hydrochemical parameters in the scale range 100 – 0:0001 mg/kg. The exponent can be 0:7 – 0:9. Power law scaling is the mathematical expression of self similarity and fractality. The complex systems of nonconservative chemical parameters have a structure that can be characterized by exponent, normalization coefficient, standard error, correlation coefficient, and by sharp deviations of the individual parameters from the regression line and from the most probable average and standard deviation values, if any. It is shown with specific examples that changes in the hydrochemical systems structure are the result of the manifestation of biogeochemical processes and the dynamics of water. Regression analysis of collective behavior of complex hydrochemical systems is one of the examples of the use of modern information technologies based on the methods of system analysis.

Sign in / Sign up

Export Citation Format

Share Document