scholarly journals EFFECTS OF WEAK EXTERNAL MECHANICAL FORCE STIMULATION ON THE HEART RATE VARIABILITY OF RATS

2004 ◽  
Vol 16 (06) ◽  
pp. 313-321 ◽  
Author(s):  
HSIN HSIU ◽  
PIN-TSUN CHAO ◽  
TSE-LIN HSU ◽  
WEI-CHEN HSU ◽  
WEI-KUNG WANG
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Mechanical Stimulation ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Circulatory System ◽  
Mechanical Force ◽  
Arterial System ◽  
Conducting System ◽  
System Effect

Motivation: The heartbeat is driven by electric signals generated inside the heart, the cardiac conducting system plays an important role. Although there are pharmacological and electrical methods working on this conducting system, effect of mechanical stimulation has rarely been discussed. Methods: We used waterbed (size 60×40×10 cm) as a media to study the heart rate variability (HRV) affected by beating the bed with weak mechanical force with 0.5-mm-Hg amplitude. The waterbed is specially designed to raise the transmission efficiency for sound wave. Results: Among 7 studies on 5 rats, there were almost no changes in diastolic pressure, systolic pressure and heart rate, but average of CV (coefficient of variance) of 15-minute heart rate sequences increased from the control value 0.0098±0.0023 (mean±SD) to 0.0119±0.0032 (mean±SD) during the stimulation and decreased to 0.0078±0.0020 (mean±SD) in 15 minutes after the stimulation [p values (paired t-test, both compared with the control) < 0.006 and < 0.0007 respectively]. Discussion: Here we show that such a weak mechanical stimulation was sufficient to affect the circulatory system. Since the effect is not directly acting on the conducting system, this small power may influence the arterial system through resonance mechanism.

Cardiac Baroreflex during the Postoperative Period in Patients with Hypertension 

1999 ◽  
Vol 90 (3) ◽  
pp. 681-692 ◽  
Author(s):  
Joel L. Parlow ◽  
Gerard Begou ◽  
Pierre Sagnard ◽  
Jean Marie Cottet-Emard ◽  
Jean Claude Levron ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Essential Hypertension ◽  
Rate Control ◽  
Diastolic Pressure ◽  
Elective Surgery ◽  
Recovery Period ◽  
Systolic Pressure ◽  
Heart Rate Control ◽  
Baroreflex Control

Background Patients with essential hypertension show altered baroreflex control of heart rate, and during the perioperative period they demonstrate increased circulatory instability. Clonidine has been shown to reduce perioperative circulatory instability. This study documents changes in measures of heart rate control after surgery in patients with essential hypertension and determines the effects of clonidine on postoperative heart rate control in these patients. Methods Using a randomized double-blind placebo-controlled design, 20 patients with essential hypertension (systolic pressure &gt;160 mm Hg or diastolic pressure &gt;95 mm Hg for &gt; or =1 yr) were assigned to receive clonidine (or placebo), 6 microg/kg orally 120 min before anesthesia and 3 microg/kg intravenously over 60 min before the end of surgery. The spontaneous baroreflex ("sequence") technique and analysis of heart rate variability were used to quantify control of heart rate at baseline, before induction of anesthesia, and 1 and 3 h postoperatively. Results Baroreflex slope and heart rate variability were reduced postoperatively in patients given placebo but not those given clonidine. Clonidine resulted in greater postoperative baroreflex slope and power at all frequency ranges compared with placebo (4.9+/-2.9 vs. 2.2+/-2.1 ms/mm Hg for baroreflex slope, 354+/-685 vs. 30+/-37 ms2/Hz for high frequency variability). Clonidine also resulted in lower concentrations of catecholamine, decreased mean heart rate and blood pressure, and decreased perioperative tachycardia and hypertension. Conclusions Patients with hypertension exhibit reduced heart rate control during the recovery period after elective surgery. Clonidine prevents this reduction in heart rate control. This may represent a basis for the improved circulatory stability seen with perioperative administration of clonidine.

Control circulatory values of morphinepentobarbitalized dogs

1960 ◽  
Vol 199 (5) ◽  
pp. 797-799 ◽  
Author(s):  
S. Deavers ◽  
E. L. Smith ◽  
R. A. Huggins
Keyword(s):  
Heart Rate ◽  
Body Weight ◽  
Cell Volume ◽  
Blood Volume ◽  
Plasma Volume ◽  
Protein Concentration ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Control Data ◽  
Plasma Protein Concentration

Mean control data on a series of 100 dogs are presented. Cell volume, measured with Cr51-tagged red cells and plasma volume determined simultaneously by T-1824 dye was 33.5 ± 0.74 cc/kg and 50.2 ± 1.11 cc/kg, respectively. The venous hematocrit was 45.2% and the circulatory/venous hematocrit ratio was 0.89 ± 0.01 for the group. The plasma protein concentration of these animals was 6.25 ± 0.07 gm/100 cc. No difference in blood volume per unit of body weight was found between large (12.6 kg) and small (5.8 kg) dogs. The femoral mean systolic pressure was 139.0 ± 2.53 mm Hg, the diastolic pressure 65.6 ± 1.46 mm Hg and the heart rate 85.9 ± 2.86/min.

Effect of sleep restriction on orthostatic cardiovascular control in humans

2000 ◽  
Vol 88 (3) ◽  
pp. 966-972 ◽  
Author(s):  
N. K. Muenter ◽  
D. E. Watenpaugh ◽  
W. L. Wasmund ◽  
S. L. Wasmund ◽  
S. A. Maxwell ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Lower Body Negative Pressure ◽  
Systolic Pressure ◽  
Cardiovascular Responses ◽  
Sleep Restriction ◽  
Orthostatic Tolerance ◽  
Arterial Baroreflex ◽  
Finger Arterial Pressure ◽  
Before And After

We hypothesized that sleep restriction (4 consecutive nights, 4 h sleep/night) attenuates orthostatic tolerance. The effect of sleep restriction on cardiovascular responses to simulated orthostasis, arterial baroreflex gain, and heart rate variability was evaluated in 10 healthy volunteers. Arterial baroreflex gain was determined from heart rate responses to nitroprusside-phenylephrine injections, and orthostatic tolerance was tested via lower body negative pressure (LBNP). A Finapres device measured finger arterial pressure. No difference in baroreflex function, heart rate variability, or LBNP tolerance was observed with sleep restriction ( P > 0.3). Systolic pressure was greater at −60 mmHg LBNP after sleep restriction than before sleep restriction (110 ± 6 and 124 ± 3 mmHg before and after sleep restriction, respectively, P = 0.038), whereas heart rate decreased (108 ± 8 and 99 ± 8 beats/min before and after sleep restriction, respectively, P = 0.028). These data demonstrate that sleep restriction produces subtle changes in cardiovascular responses to simulated orthostasis, but these changes do not compromise orthostatic tolerance.

Alcohol: Effect on Blood Pressure and Predisposition to Hypertension

1981 ◽  
Vol 61 (s7) ◽  
pp. 373s-375s ◽  
Author(s):  
P. D. Arkwright ◽  
L. J. Beilin ◽  
I. Rouse ◽  
B. K. Armstrong ◽  
R. Vandongen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Essential Hypertension ◽  
Alcohol Consumption ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Threshold Effect ◽  
Health Questionnaire ◽  
Government Employees ◽  
Weekly Alcohol Consumption

1. The association between alcohol consumption and blood pressure was studied in 491 Government employees. The men, aged 21–45 years, volunteered to complete a health questionnaire and submitted to standardized measurements of blood pressure, heart rate and body size. 2. Average weekly alcohol consumption correlated with systolic pressure (r = 0.18, P &lt; 0.001) but not with diastolic pressure. Systolic pressure increased progressively with increasing alcohol consumption with no obvious threshold effect. The effect of alcohol was independent of age, obesity (Quetelet's index) or cigarette smoking. 3. Results indicate that alcohol ranks close to obesity as a preventable cause of essential hypertension in the community.

scholarly journals Effects of Imagery as Visual Stimuli on the Physiological and Emotional Responses

J ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 206-225 ◽  
Author(s):  
Nadeesha Gunaratne ◽  
Claudia Viejo ◽  
Thejani Gunaratne ◽  
Damir Torrico ◽  
Hollis Ashman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Diastolic Pressure ◽  
Visual Stimuli ◽  
Systolic Pressure ◽  
Emotional Responses ◽  
Accurate Information ◽  
Dimensional Model ◽  
Picture Database ◽  
Face Scale ◽  
General Linear Regression Model

Study of emotions has gained interest in the field of sensory and consumer research. Accurate information can be obtained by studying physiological behavior along with self-reported-responses. The aim was to identify physiological and self-reported-responses towards visual stimuli and predict self-reported-responses using biometrics. Panelists (N = 63) were exposed to 12 images (ten from Geneva Affective PicturE Database (GAPED), two based on common fears) and a questionnaire (Face scale and EsSense). Emotions from facial expressions (FaceReaderTM), heart rate (HR), systolic pressure (SP), diastolic pressure (DP), and skin temperature (ST) were analyzed. Multiple regression analysis was used to predict self-reported-responses based on biometrics. Results showed that physiological along with self-reported responses were able to separate images based on cluster analysis as positive, neutral, or negative according to GAPED classification. Emotional terms with high or low valence were predicted by a general linear regression model using biometrics, while calm, which is in the center of emotion dimensional model, was not predicted. After separating images, positive and neutral categories could predict all emotional terms, while negative predicted Happy, Sad, and Scared. Heart Rate predicted emotions in positive (R2 = 0.52 for Scared) and neutral (R2 = 0.55 for Sad) categories while ST in positive images (R2 = 0.55 for Sad, R2 = 0.45 for Calm).

The Effects of Cardioselective and Non-Selective β-Adrenoceptor Blockade on the Hypokalaemic and Cardiovascular Responses to Adrenomedullary Hormones in Man

1983 ◽  
Vol 65 (2) ◽  
pp. 143-147 ◽  
Author(s):  
A. D. Struthers ◽  
J. L. Reid ◽  
R. Whitesmith ◽  
J. C. Rodger
Keyword(s):  
Heart Rate ◽  
Serum Potassium ◽  
Qt Interval ◽  
Diastolic Pressure ◽  
Plasma Concentrations ◽  
Systolic Pressure ◽  
Cardiovascular Responses ◽  
Potassium Influx ◽  
Adrenomedullary Hormones ◽  
Stimulation Of

1. Adrenaline was infused intravenously in nine normal volunteers to plasma concentrations similar to those found after myocardial infarction. This study was undertaken on three occasions after 5 days' treatment with placebo or the β-adrenoceptor antagonists, atenolol or timolol. 2. Adrenaline increased the systolic pressure by 11 mmHg, decreased the diastolic pressure by 14 mmHg, and increased the heart rate by 7 beats/min. These changes were prevented by atenolol. However, after timolol the diastolic pressure rose (+19 mmHg) and heart rate fell (− 8 beats/min). 3. Adrenaline caused the corrected QT interval (QTc) to lengthen (0.36 ± 0.02 s to 0.41 ± 0.06 s). No significant changes were found in the QTc when subjects were pretreated with atenolol or timolol. 4. The serum potassium fell from 4.06 to 3.22 mmol/l after adrenaline. Serum potassium fell to a lesser extent to 3.67 mmol/l after atenolol and actually increased to 4.25 mmol/l after timolol. Adrenaline-mediated hypokalaemia appears to result from the stimulation of a β2-adrenoceptor linked to membrane Na+/K+-ATPase causing potassium influx.

Normalized input impedance and arterial decay time over heart period are independent of animal size

1991 ◽  
Vol 261 (1) ◽  
pp. R126-R133 ◽  
Author(s):  
N. Westerhof ◽  
G. Elzinga
Keyword(s):  
Heart Rate ◽  
Decay Time ◽  
Input Impedance ◽  
Diastolic Pressure ◽  
Arterial Compliance ◽  
Characteristic Impedance ◽  
Peripheral Resistance ◽  
Arterial System ◽  
Heart Period ◽  
Arterial Tree

The arterial system of mammals in the weight range from 0.6 to 70 kg is characterized by the three-element windkessel, a succinct representation of the arterial tree consisting of the parameters peripheral resistance (Rp), total arterial compliance (C), and aortic characteristic impedance (Zc). The values of these parameters in resting conditions are related to body mass (M). The time constant, or decay time (tau), of the arterial system (defining rate of decay of aortic pressure in diastole), the product of Rp and C, is also evaluated. The dependencies of the heart period (T, inverse of heart rate), and durations of ejection (Ts) and of diastole (Td) in resting conditions are also determined as a function of M. It is found that Rp = Rp0M-0.93; Zc = Zc0M-0.97; and C = C0M+1.23, where Rp0, Zc0, and C0 are proportionality constants. Zc is thus a constant fraction of Rp in all mammals. tau is related to M as tau = tau 0M+0.29; T and Td are related to M as T = T0M+0.27 and Td = Td0M+0.30, where tau 0, T0, and Td0 are proportionality constants. The duration of diastole is thus a constant fraction of T, and the ratios T/tau and Td/tau are independent of M. The findings indicate that arterial input impedance, normalized to aortic Zc and plotted as a function of frequency normalized to heart rate, is similar for all mammals. The finding that the ratio Td/tau is the same in mammals (and Ts/T and stroke volume/M are constant) explains the constancy of pulse pressure (systolic minus diastolic pressure).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Intraarterial Blood Pressure Response to Bench Press Weight Lifting in Children

1990 ◽  
Vol 2 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Karen L. Nau ◽  
Victor L. Katch ◽  
Robert H. Beekman ◽  
Macdonald Dick
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Bench Press ◽  
Diastolic Pressure ◽  
Blood Pressure Response ◽  
Systolic Pressure ◽  
Weight Lifting ◽  
Peak Heart Rate ◽  
Repetition Maximum ◽  
Peak Pressures

Intraarterial blood pressure (BP) response to bench press weight lifting (WL) was evaluated in 11 children. Aortic systolic and diastolic pressures and heart rate (HR) were measured during WL. Baseline systolic and diastolic pressures were 120 and 81 mmHg, and HR was 86 bpm. Subjects lifted to voluntary fatigue weights equaling 60, 75, 90, and 100% of their predetermined one-repetition maximum (1RM). For each weight lifting condition, BP and HR increased as more repetitions were completed. Peak systolic pressure was 168, 177, 166, and 162 mmHg, peak diastolic pressure was 125, 139, 133, and 130 mmHg, and peak heart rate was 142, 148, 142, and 139 bpm at 60, 75, 90, and 100% 1RM, respectively. Peak BP and HR were greater during WL than rest but did not differ between conditions. The relative BP response to WL in children was similar to adult values. For all conditions, pressures increased as more repetitions were completed. It was concluded that peak pressures occur at voluntary fatigue, independent of the combination of resistance and repetitions used to achieve fatigue.

scholarly journals CARDIAC FUNCTION OF BASKETBALL PLAYERS UNDER STRESS TRAINING

2022 ◽  
Vol 28 (1) ◽  
pp. 27-30
Author(s):  
Keyin Liu
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Diastolic Pressure ◽  
Test Procedure ◽  
Systolic Pressure ◽  
Cardiac Response ◽  
Training Methods ◽  
Basketball Players ◽  
Level Of Evidence ◽  
Athletic Ability

ABSTRACT Introduction: Basketball can enhance the physical fitness of young people, promote the growth and development of their bodies, and improve health and athletic ability. Objective: To explore the characteristics of basketball players’ cardiac response to increasing load training. Methods: By analyzing 12 juvenile male amateur basketball training athletes, when performing incremental load exercises on the treadmill, using a 12-lead electrocardiograph to record the electrocardiogram, HR, and blood pressure responses for each level of exercise. Results: The mean heart rate of the basketball players before movement was 82.45± 11.44 bpm, slightly higher than the heart rate at rest. Depending on the exercise load, the blood pressure should increase by 5 to 12 mmHg. Under different load training conditions, each level of blood pressure in the Bruce treadmill test procedure should increase 12.5 ~ 44mmHg. The basketball player’s systolic pressure increased by 2.25 ~ 15.7mmHg, diastolic pressure increased by 0.43 to 11.37 mmHg. Conclusions: In basketball players, the psychological stress is less than that of the average person performing the same exercise. The strong ability to adapt to exercise under incremental load training, the contractility of the ventricular muscles and the development of the heart are good. Level of evidence II; Therapeutic studies - investigation of treatment results.

scholarly journals Comparison of Haemodynamic Response to Intubation with KingVision and C-MAC Videolaryngoscope in Adults

2020 ◽  
Author(s):  
Prathima Padavarahalli Thammanna ◽  
Kavya Marasandra Seetharam ◽  
Tejesh Channasandra Anandaswamy ◽  
Prapti Rath ◽  
Geetha Chamanhalli Rajappa ◽  
...  
Keyword(s):  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
General Anaesthesia ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Haemodynamic Response ◽  
Time Points ◽  
Universal Device ◽  
Spss Software

Background: Videolaryngoscopes are now being advocated as the universal device for airway management due to their ability to provide an improved glottic visualisation. Due to their ability to see around the corners, they obviate the need to align the airway axes and thus may lead to less airway stimulation. This may result in less haemodynamic response during laryngoscopy and intubation. The present study was designed to compare the haemodynamic response to intubation with King Vision and C-MAC videolaryngoscopes. Methods: After obtaining informed consent, adults with unanticipated difficult intubation, scheduled to undergo surgery under general anaesthesia were randomised to be intubated with either King Vision (Group K) or C-MAC (Group C) videolaryngoscope. Following a standardised general anaesthesia induction protocol all subjects were intubated with the allocated videolaryngoscope and haemodynamic parameters (heart rate, systolic pressure, diastolic pressure and mean arterial pressure) were recorded at specific time points. Statistical analysis was done using the SPSS Software (version 18.0). Results: The changes in the heart rate, systolic pressure, diastolic pressure and mean arterial pressure following laryngoscopy and intubation with the allocated videolaryngoscope were statistically similar between the two groups at all time points. Conclusion: Haemodynamic responses to laryngoscopy and intubation with King Vision and C-MAC videolaryngoscopes were similar.

Sign in / Sign up

Export Citation Format

Share Document