Cardiovascular regulation during head-up tilt in healthy 20–30-year-old and 70–75-year-old men

2001 ◽  
Vol 100 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Tim J. GABBETT ◽  
Shane B. WESTON ◽  
Rod S. BARRETT ◽  
Greg C. GASS
Keyword(s):  
Tibialis Anterior ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Young Men ◽  
Older Men ◽  
Emg Activity ◽  
Orthostatic Stress ◽  
Vastus Medialis ◽  
Head Up Tilt ◽  
Finger Systolic Pressure

This study compared the heart rate, finger arterial pressure (AP) and electromyographic (EMG) activity of selected anti-gravity muscles during the initial and prolonged phases of orthostatic stress in healthy young and older men. Beat-by-beat recordings of heart rate, finger systolic pressure, diastolic pressure and mean AP were made during supine rest and 5 min of 90 ° head-up tilt (HUT) in 18 young (23±1 years) and 15 older (73±1 years) men. The EMG activity of the soleus, tibialis anterior and vastus medialis muscles was recorded. During the first 30 s following 90 ° HUT (immediate response), the young men exhibited significant (P < 0.05) decreases in finger systolic pressure, diastolic pressure and mean AP, followed by a sustained increase in finger AP during the 5 min following 90 ° HUT (prolonged response). The immediate and prolonged finger AP and diastolic pressure responses were not significantly different (P > 0.05) from the values at supine rest for the older men. The mean root mean square EMG activity of the soleus, tibialis anterior and vastus medialis muscles during 90 ° HUT was not significantly different (P > 0.05) from that at supine rest for either group. These results demonstrate that, when compared with healthy older men, young men show larger reductions in finger AP during the initial phase of orthostatic stress. However, during the prolonged phase of orthostatic stress, older men maintain resting finger AP, whereas young men demonstrate a reflex overshoot in finger AP. Finally, differences in lower-limb anti-gravity muscle activation do not account for the contrasting finger AP responses of healthy young and older men.

Circulatory response to postural change in healthy male subjects in relation to age

1987 ◽  
Vol 72 (3) ◽  
pp. 335-341 ◽  
Author(s):  
J. H. A. Dambrink ◽  
W. Wieling
Keyword(s):  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Elderly Subjects ◽  
Postural Change ◽  
Pronounced Increase ◽  
Standing Up ◽  
Head Up Tilt ◽  
Young Subjects ◽  
Old Men ◽  
Male Subjects

1. The initial heart rate (HR) response evoked by standing up and 70° head-up tilt from the supine resting position, as well as the changes in HR and blood pressure after 1–2 min in the upright position, was analysed in teenage boys (aged 10–15 years) and healthy old men (aged 60–90 years). 2. Standing up induced a characteristic temporary HR increase that lasted 20 s and far exceeded the gradual initial HR rise induced by head-up tilt. The main effect of age on the initial HR transients was a definite diminution of the response. 3. After 1–2 min standing and tilting, young subjects showed a pronounced increase in HR and diastolic pressure with little change in systolic pressure. In contrast, old subjects showed a lesser increase in HR and diastolic pressure and a decrease in systolic pressure. A fall in systolic pressure of greater than 20 mmHg after 1 min of active standing was, however, not observed. 4. It is concluded that the circulatory adjustment to the stress of postural change differs markedly between young and elderly subjects. In healthy old subjects marked postural hypotension appears to be rare.

scholarly journals Telomere Length as a Biomarker for Race-Related Health Disparities

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 78
Author(s):  
Vaithinathan Selvaraju ◽  
Megan Phillips ◽  
Anna Fouty ◽  
Jeganathan Ramesh Babu ◽  
Thangiah Geetha
Keyword(s):  
Blood Pressure ◽  
Telomere Length ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Single Copy ◽  
Normal Weight ◽  
Length Ratio ◽  
Hierarchical Regression ◽  
Significant Difference ◽  
The Usa

Disparities between the races have been well documented in health and disease in the USA. Recent studies show that telomere length, a marker of aging, is associated with obesity and obesity-related diseases, such as heart disease and diabetes. The current study aimed to evaluate the connection between telomere length ratio, blood pressure, and childhood obesity. The telomere length ratio was measured in 127 children from both European American (EA) and African American (AA) children, aged 6–10 years old. AA children had a significantly high relative telomere to the single copy gene (T/S) ratio compared to EA children. There was no significant difference in the T/S ratio between normal weight (NW) and overweight/obese (OW/OB) groups of either race. Blood pressure was significantly elevated in AA children with respect to EA children. Hierarchical regression analysis adjusted for race, gender, and age expressed a significant relationship between the T/S ratio and diastolic pressure. Low T/S ratio participants showed a significant increase in systolic pressure, while a high T/S ratio group showed an increase in diastolic pressure and heart rate of AA children. In conclusion, our findings show that AA children have high T/S ratio compared to EA children. The high T/S ratio is negatively associated with diastolic pressure.

Diastolic pressure, systolic pressure, or pulse pressure?

2000 ◽  
Vol 2 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Charalambos Vlachopoulos ◽  
Michael O’Rourke
Keyword(s):  
Pulse Pressure ◽  
Diastolic Pressure ◽  
Systolic Pressure

Lower-Extremity Muscle Activity During Aquatic and Land Treadmill Running at the Same Speeds

2014 ◽  
Vol 23 (2) ◽  
pp. 107-122 ◽  
Author(s):  
W. Matthew Silvers ◽  
Eadric Bressel ◽  
D. Clark Dickin ◽  
Garry Killgore ◽  
Dennis G. Dolny
Keyword(s):  
Lower Extremity ◽  
Outcome Measures ◽  
Muscle Activity ◽  
Tibialis Anterior ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Swing Phase ◽  
Treadmill Running ◽  
Vastus Medialis ◽  
Lower Extremity Muscle

Context:Muscle activation during aquatic treadmill (ATM) running has not been examined, despite similar investigations for other modes of aquatic locomotion and increased interest in ATM running.Objectives:The objectives of this study were to compare normalized (percentage of maximal voluntary contraction; %MVC), absolute duration (aDUR), and total (tACT) lower-extremity muscle activity during land treadmill (TM) and ATM running at the same speeds.Design:Exploratory, quasi-experimental, crossover design.Setting:Athletic training facility.Participants:12 healthy recreational runners (age = 25.8 ± 5 y, height = 178.4 ± 8.2 cm, mass = 71.5 ± 11.5 kg, running experience = 8.2 ± 5.3 y) volunteered for participation.Intervention:All participants performed TM and ATM running at 174.4, 201.2, and 228.0 m/min while surface electromyographic data were collected from the vastus medialis, rectus femoris, gastrocnemius, tibialis anterior, and biceps femoris.Main Outcome Measures:For each muscle, a 2 × 3 repeated-measures ANOVA was used to analyze the main effects and environment–speed interaction (P ≤ .05) of each dependent variable: %MVC, aDUR, and tACT.Results:Compared with TM, ATM elicited significantly reduced %MVC (−44.0%) but increased aDUR (+213.1%) and tACT (+41.9%) in the vastus medialis, increased %MVC (+48.7%) and aDUR (+128.1%) in the rectus femoris during swing phase, reduced %MVC (−26.9%) and tACT (−40.1%) in the gastrocnemius, increased aDUR (+33.1%) and tACT (+35.7%) in the tibialis anterior, and increased aDUR (+41.3%) and tACT (+29.2%) in the biceps femoris. At faster running speeds, there were significant increases in tibialis anterior %MVC (+8.6−15.2%) and tACT (+12.7−17.0%) and rectus femoris %MVC (12.1−26.6%; swing phase).Conclusion:No significant environment–speed interaction effects suggested that observed muscle-activity differences between ATM and TM were due to environmental variation, ie, buoyancy (presumed to decrease %MVC) and drag forces (presumed to increase aDUR and tACT) in the water.

The Correspondence Between Some Motor Points and Acupuncture Loci

1975 ◽  
Vol 03 (04) ◽  
pp. 347-358 ◽  
Author(s):  
Y. King Liu ◽  
Maria Varela ◽  
Robert Oswald
Keyword(s):  
Statistical Analysis ◽  
Tibialis Anterior ◽  
Double Blind Study ◽  
Vastus Medialis ◽  
Abductor Pollicis Brevis ◽  
Double Blind ◽  
Orbicularis Oculi ◽  
Peroneus Longus ◽  
Uv Illumination ◽  
Splenius Capitis

A double blind study was conducted to establish the possible correspondence between some motor points and acupuncture loci. THe protocol calls for the acupuncturist marking the first group of volunteers with invisible ink at the acupuncture loci. Then the motor points in the same volunteer are found by electrodiagnosis. The error is made visible by UV illumination. In the second group, the procedure is reversed. A statistical analysis of the error yields the following classes of correspondences: (a) Excellent: 1st Dorsal Interosseus (hand) = LI-4; Abductor Pollicis Brevis = Lu-10; Abductor Minimi Digiti = SI-4; 1st Dorsal Interosseus (foot)=LI-3; Tibialis Anterior = Curious Locus; Orbicularis Oculi = GB-I; Frontalis = GB-14; Splenius Capitis = GB-20; Sternocleidomastoid = LI-18; Semi-Spinalis Capitis = BI-10. (b) Good: Opponens Pollicis = Curious Locus; Peroneus Longus = Curious Locus; Flexior Digitorum Longus = Ki-3 (Ki-6); Trapezius (upper) = GB-21; Rectus Abdominis=Ki-15; Vastus Medialis = Sp-10.

Use of Multiple Visits to Increase Blood Pressure Tracking Correlations in Childhood

PEDIATRICS ◽  
1991 ◽  
Vol 87 (5) ◽  
pp. 708-711
Author(s):  
Matthew W. Gillman ◽  
Bernard Rosner ◽  
Denis A. Evans ◽  
Laurel A. Smith ◽  
James O. Taylor ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Correlation Coefficient ◽  
Diastolic Pressure ◽  
Pearson Correlation ◽  
Systolic Pressure ◽  
Pearson Correlation Coefficient ◽  
Increase Blood Pressure ◽  
Multiple Visit

Previous studies of childhood blood pressure have shown tracking correlations, which estimate the magnitude of association between initial and subsequent measurements, to be lower than corresponding adult values. Inasmuch as this disparity could arise from failing to account for a larger week-to-week variability in children, blood pressure was measured for 4 successive years, on four weekly visits in each year, and with three measurements at each visit, using a random-zero sphygmomanometer, in a cohort of 333 schoolchildren aged 8 through 15 at entry. Ninety percent of subjects had measurements in 1 or more years of follow-up. For all follow-up periods (1, 2, and 3 years from baseline), the Pearson correlation coefficient (r) for both systolic and diastolic blood pressure rose substantially with the number of weekly visits used to calculate each subject's yearly blood pressure (P &lt; .0001). For systolic pressure, the 3-year r values for 1, 2, 3, and 4 visits were .45, .55, .64, and .69, respectively. For diastolic pressure (Korotkoff phase 4), the corresponding values were .28, .41, .47, and .54. These higher multiple-visit estimates of tracking approximate published adult values and raise the possibility that prediction of adult blood pressure from childhood measurements may be improved by averaging readings from multiple weekly visits.

Right ventricular pressure response to +GZ acceleration stress

1982 ◽  
Vol 53 (4) ◽  
pp. 908-913 ◽  
Author(s):  
J. E. Whinnery ◽  
M. H. Laughlin
Keyword(s):  
Right Ventricular ◽  
Diastolic Pressure ◽  
Vena Cava ◽  
Systolic Pressure ◽  
Ventricular Pressure ◽  
Miniature Swine ◽  
Right Ventricular Systolic Pressure ◽  
Ventricular Systolic Pressure ◽  
The Right ◽  
Acceleration Stress

Measurements of right ventricular pressure in miniature swine were made at +Gz levels from +1 through +9 Gz. Polyethylene catheters were chronically placed in the cranial vena cava of five 2-yr-old female miniature swine (35–50 kg). The catheters were large enough to allow the introduction of a Millar pressure transducer into the venous system for placement in the right heart. The animals were fitted with an abdominal anti-G suit, restrained in a fiberglass couch, and exposed to the various +Gz levels on a centrifuge while fully conscious and unanesthetized. Right ventricular pressure and heart rate were measured during and for 2 min following 30-s exposures to each level of +Gz stress. The maximum right ventricular systolic pressure observed during +Gz was 200 Torr at +5 Gz with the maximum diastolic pressure being 88 Torr observed at +5 Gz. Mean heart rates were 200–210 beats/min at all levels of +Gz greater than or equal to +3 Gz when the animal remained stable. Mean maximum right ventricular pressures during +Gz stress were observed to increase through +5 Gz (85 Torr) and to decrease at higher levels of +Gz, indicating that through +5 Gz there is at least a partial compensation during acceleration stress. Decompensation in response to the stress began to occur during acceleration above +5 Gz with all animals decompensating during +9 Gz.

The Effect of Gypenosides on Cardiac Function and Expression of Cytoskeletal Genes of Myocardium in Diabetic Cardiomyopathy Rats

2009 ◽  
Vol 37 (06) ◽  
pp. 1059-1068 ◽  
Author(s):  
Min Ge ◽  
Shanfeng Ma ◽  
Liang Tao ◽  
Sudong Guan
Keyword(s):  
Cardiac Function ◽  
Diabetic Cardiomyopathy ◽  
Diastolic Pressure ◽  
Pure Water ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Control Group ◽  
Sprague Dawley ◽  
Gene Expressions ◽  
Ventricular Systolic Pressure

The relationship between changes of cardiac function and the gene expressions of two major myocardial skeleton proteins, titin and nebulin, and the effect of gypenosides on these gene expressions in diabetic cardiomyopathy rat were explored in the present study. Forty Sprague-Dawley rats were randomly divided into three groups: control group, diabetic cardiomyopathy group and gypenosides-treated diabetic cardiomyopathy group. The diabetic cardiomyopathy was induced in rats by injecting streptozotocin (STZ, 55 mg/kg) intraperitoneally. Seven weeks after the rats suffered from diabetes, the rats were treated with gypenosides 100 mg/kg per day orally for six weeks in gypenosides-treated group. In the meanwhile, the pure water was given to diabetic cardiomyopathy and the control groups. Subsequently, the cardiac functions, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), ± dP/dtmax and t–dP/dmaxt, as well as the mRNA content and proteins of titin and nebulin in myocardium were determined. The results indicated that (1) the diabetic cardiomyopathy rats had decreased LVSP and ± dP/dtmax, increased LVEDP, and prolonged t–dP/dtmax than normal rats; (2) LVSP and ± dP/dtmax in diabetic cardiomyopathy rats treated with gypenosides were significantly higher and LVEDP and t–dP/dtmax were significantly lower than those without giving gypenosides; (3) the mRNA contents and proteins of titin and nebulin in diabetic cardiomyopathy rats were remarkably lower than those in the control rats and gypenosides had no effect on mRNA and protein expression levels of titin and nebulin in diabetic cardiomyopathy rats. We conclude that (1) the cardiac function as well as the mRNA expressions of titin and nebulin decreased in diabetic cardiomyopathy rats; (2) gypenosides secure cardiac muscles and their function from diabetic impairment and these beneficial effects of gypenosides are not by changing the expressions of titin and nebulin.

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.

Sign in / Sign up

Export Citation Format

Share Document