The effect of exposure to high and low frequency hand-arm vibration on finger systolic pressure

1987 ◽  
Vol 56 (4) ◽  
pp. 440-443 ◽  
Author(s):  
E. Matikainen ◽  
H. Leinonen ◽  
J. Juntunen ◽  
A. -M. Sepp�l�inen
Keyword(s):  
Systolic Pressure ◽  
Low Frequency ◽  
Finger Systolic Pressure

Exploring directionality in spontaneous heart period and systolic pressure variability interactions in humans: implications in the evaluation of baroreflex gain

2005 ◽  
Vol 288 (4) ◽  
pp. H1777-H1785 ◽  
Author(s):  
Giandomenico Nollo ◽  
Luca Faes ◽  
Alberto Porta ◽  
Renzo Antolini ◽  
Flavia Ravelli
Keyword(s):  
Spectral Analysis ◽  
Spectral Component ◽  
Systolic Pressure ◽  
Low Frequency ◽  
Systolic Arterial Pressure ◽  
Phase Lag ◽  
Healthy Humans ◽  
Head Up Tilt ◽  
Causal Approach ◽  
Young Subjects

Although in physiological conditions RR interval and systolic arterial pressure (SAP) are likely to interact in a closed loop, the traditional cross-spectral analysis cannot distinguish feedback (FB) from feedforward (FF) influences. In this study, a causal approach was applied for calculating the coherence from SAP to RR ( Ks-r) and from RR to SAP ( Kr-s) and the gain and phase of the baroreflex transfer function. The method was applied, compared with the noncausal one, to RR and SAP series taken from 15 healthy young subjects in the supine position and after passive head-up tilt. For the low frequency (0.04–0.15 Hz) spectral component, the enhanced FF coupling ( Kr-s = 0.59 ± 0.21, significant in 14 subjects) and the blunted FB coupling ( Ks-r = 0.17 ± 0.17, significant in 4 subjects) found at rest indicated the prevalence of nonbaroreflex mechanisms. The tilt maneuver recovered FB influences ( Ks-r = 0.47 ± 0.16, significant in 14 subjects), which were stronger than FF interactions ( Ks-r = 0.34 ± 0.19, significant in 9 subjects). At the respiratory frequency, the RR-SAP regulation was balanced at rest ( Ks-r = 0.30 ± 0.18 and Kr-s = 0.29 ± 0.20, significant in 11 and 8 subjects) and shifted toward FB mechanisms after tilt ( Ks-r = 0.35 ± 0.19 and Kr-s = 0.19 ± 0.11, significant in 14 and 8 subjects). The causal baroreflex gain estimates were always lower than the corresponding noncausal values and decreased significantly from rest to tilt in both frequency bands. The tilt-induced increase of the phase lag from SAP to RR suggested a shift from vagal to sympathetic modulation. Thus the importance of nonbaroreflex interactions pointed out the necessity of accounting for causality in the cross-spectral analysis of the interactions between cardiovascular variables in healthy humans.

scholarly journals Cardiac Autonomic Modulation in Response to Muscle Fatigue and Sex Differences During Consecutive Competition Periods in Young Swimmers: A Longitudinal Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Matías Castillo-Aguilar ◽  
Pablo Valdés-Badilla ◽  
Tomás Herrera-Valenzuela ◽  
Eduardo Guzmán-Muñoz ◽  
Pedro Delgado-Floody ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Body Fat ◽  
Systolic Pressure ◽  
Low Frequency ◽  
Wingate Test ◽  
Autonomic Modulation ◽  
Cardiac Autonomic Modulation ◽  
Before And After ◽  
Longitudinal Variations ◽  
Mean Pressure

Objective: To study the differences in cardiac autonomic modulation in response to muscle fatigue caused by high-intensity exercise during two consecutive competition periods in young swimmers.Methods: Twenty-six competitive swimmers, selected by their training volume, were separated in two groups, females (n = 12 [46%], age: 13.5 ± 1.4 years) and males (n = 14 [54%], age: 13.9 ± 1.7 years), aged between 10 and 16 years, were evaluated five times as follow: (i) 21 days before the first competition (t-0); (ii) two days before (t-1; t-3); and (iii) two days after (t-2; t-4) of the first and second competitions. Morphological measurements (body mass, percentage of total body fat and height), blood pressure, power, and resting heart rate variability (RR with Polar band) were recorded before and after Wingate test at each time.Results: Body fat was higher in females compared to males. However, no differences were found in other morphological parameters. An intra-subject analysis grouped by sex in cardiovascular parameters shows longitudinal variations in systolic pressure and mean pressure among females. Additionally, females depicted higher, very low frequency (VLF, which is intrinsically generated by the heart and strongly associated with emotional stress) after physical fatigue compared to males at t-1. Further, before the competition, the high frequency (HF) component of HRV (parasympathetic drive) was higher in males than females at t-0 and t-4.Conclusion: Our data revealed that males displayed greater parasympathetic reactivity after an anaerobic muscle fatigue test during their competition periods. Contrarily, females had a less cardiac autonomic modulation when comparing the pre-post Wingate test after two consecutive competition periods.

Controlled breathing protocols probe human autonomic cardiovascular rhythms

1998 ◽  
Vol 274 (2) ◽  
pp. H709-H718 ◽  
Author(s):  
William H. Cooke ◽  
James F. Cox ◽  
André M. Diedrich ◽  
J. Andrew Taylor ◽  
Larry A. Beightol ◽  
...  
Keyword(s):  
Arterial Pressure ◽  
Transfer Functions ◽  
Spectral Power ◽  
Systolic Pressure ◽  
Low Frequency ◽  
Volume Control ◽  
Fixed Frequency ◽  
Random Frequency ◽  
End Tidal ◽  
Cardiovascular Rhythms

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.

scholarly journals Respiratory modulation of human autonomic rhythms

2001 ◽  
Vol 280 (6) ◽  
pp. H2674-H2688 ◽  
Author(s):  
Leslie J. Badra ◽  
William H. Cooke ◽  
Jeffrey B. Hoag ◽  
Alexandra A. Crossman ◽  
Tom A. Kuusela ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Muscle Sympathetic Nerve Activity ◽  
Systolic Pressure ◽  
Power Spectra ◽  
Low Frequency ◽  
Partial Coherence ◽  
Low Frequencies ◽  
Spectral Techniques ◽  
Reflex Gain ◽  
Spontaneous Frequency

We studied the influence of three types of breathing [spontaneous, frequency controlled (0.25 Hz), and hyperventilation with 100% oxygen] and apnea on R-R interval, photoplethysmographic arterial pressure, and muscle sympathetic rhythms in nine healthy young adults. We integrated fast Fourier transform power spectra over low (0.05–0.15 Hz) and respiratory (0.15–0.3 Hz) frequencies; estimated vagal baroreceptor-cardiac reflex gain at low frequencies with cross-spectral techniques; and used partial coherence analysis to remove the influence of breathing from the R-R interval, systolic pressure, and muscle sympathetic nerve spectra. Coherence among signals varied as functions of both frequency and time. Partialization abolished the coherence among these signals at respiratory but not at low frequencies. The mode of breathing did not influence low-frequency oscillations, and they persisted during apnea. Our study documents the independence of low-frequency rhythms from respiratory activity and suggests that the close correlations that may exist among arterial pressures, R-R intervals, and muscle sympathetic nerve activity at respiratory frequencies result from the influence of respiration on these measures rather than from arterial baroreflex physiology. Most importantly, our results indicate that correlations among autonomic and hemodynamic rhythms vary over time and frequency, and, thus, are facultative rather than fixed.

Points: Finger systolic pressure

BMJ ◽  
1986 ◽  
Vol 293 (6558) ◽  
pp. 1375-1375
Author(s):  
A. Close ◽  
G T Hamilton
Keyword(s):  
Systolic Pressure ◽  
Finger Systolic Pressure
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