A Modified Method of Quantifying the Carotid Baroreceptor-Heart Rate Reflex in Man: The Effect of Age and Blood Pressure

1989 ◽  
Vol 77 (2) ◽  
pp. 223-228 ◽  
Author(s):  
M. R. Cowie ◽  
J. M. Rawles
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Baroreflex Sensitivity ◽  
Rate Sensitivity ◽  
Modified Method ◽  
Carotid Baroreceptor ◽  
Blood Pressures ◽  
The Mean ◽  
Neck Chamber ◽  
Effect Of Age

1. Carotid baroreceptor-heart rate sensitivity has been measured non-invasively by a modified neck-chamber method that utilizes all cardiac intervals recorded in 6 min during 84 respiratory cycles. 2. In a replication study in 10 subjects the mean baroreflex sensitivity was 5.52 ms/mmHg and the mean (sd) difference between determinations was 0.70 (0.74) ms/mmHg. 3. Baroreflex sensitivity was measured in 48 untreated subjects of mean age 43 (range 20–71) years with blood pressures ranging from 104 to 202 mmHg (13.9 to 26.9 kPa) systolic and 52 to 120 mmHg (6.9 to 16.0 kPa) diastolic [average 142/87 mmHg (18.9/11.6 kPa)]. Both systolic and diastolic pressures correlated with age (r = 0.53, P < 0.001 and r = 0.44, P < 0.01). 4. Baroreflex sensitivity determined throughout respiration was log-normally distributed with a median value of 2.24 ms/mmHg, which declined with age (r = −0.63, P < 0.001). 5. After allowing for the effects of age, baroreflex sensitivity throughout respiration was not independently related to either systolic or diastolic blood pressure.

scholarly journals Etorphine-halothane anaesthesia in two five-year-old African elephants (Loxodonta africana) : clinical communication

1999 ◽  
Vol 70 (4) ◽  
Author(s):  
G.F. Stegmann
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Pressure ◽  
Loxodonta Africana ◽  
African Elephants ◽  
Clinical Communication ◽  
Dental Surgery ◽  
Blood Pressures ◽  
The Mean ◽  
Mean Heart Rate

Anaesthesia of 2 five-year-old femaleAfrican elephants (Loxodonta africana) was required for dental surgery. The animals were each premedicated with 120 mg of azaperone 60 min before transportation to the hospital. Before offloading, 1 mg etorphine was administered intramuscularly (i.m.) to each elephant to facilitate walking them to the equine induction / recovery room. For induction, 2 mg etorphine was administered i.m. to each animal. Induction was complete within 6 min. Surgical anaesthesia was induced with halothane-in-oxygen after intubation of the trunk. During surgery the mean heart rate was 61 and 45 beats / min respectively. Systolic blood pressures increased to 27.5 and 25.6 kPa respectively, and were treated with intravenous azaperone. Blood pressure decreased thereafter to a mean systolic pressure of 18.1 and 19.8 kPa, respectively. Rectal temperature was 35.6 and 33.9 oC at the onset of surgery, and decreased to 35.3 and 33.5 oC, respectively, at the end of anaesthesia. Etorphine anaesthesia was reversed with 5mg diprenorphine at the completion of 90 min of surgery.

The Autonomic Nervous Tone Abnormalities in the Genesis of the Impaired Baroreflex Responsiveness in Borderline Hypertensive Subjects

1982 ◽  
Vol 62 (6) ◽  
pp. 581-588 ◽  
Author(s):  
Massimo Volpe ◽  
Bruno Trimarcoy ◽  
Bruno Ricciardelli ◽  
Carlo Vigorito ◽  
Nicola De Luca ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Pressure ◽  
Normal Subjects ◽  
Tissue Pressure ◽  
Combined Administration ◽  
Propranolol Treatment ◽  
The Mean ◽  
Pressure Changes ◽  
Neck Chamber

1. The effects of intravenous administration of neostigmine and propranolol, individually or in combination, on baroreflex responsiveness have been evaluated in 18 borderline hypertensive subjects and in 14 age-matched control subjects. 2. Baroreceptor sensitivity was tested by evaluating both heart rate response to phenylephrine-induced increase in arterial pressure, and heart rate and blood pressure changes induced by increasing neck-tissue pressure by means of a neck-chamber. 3. In borderline hypertensive subjects a reduced baroreflex responsiveness was demonstrated with both stimuli as compared with normal subjects. Neostigmine administration improved consistently both reflex responses. Similarly, after propranolol treatment, borderline hypertensive subjects showed a significant enhancement of the baroreflex sensitivity. Finally, the combined administration of neostigmine and propranolol restored the baroreflex responses. In fact, both the mean slopes of the regression lines between blood pressure and R-R interval after phenylephrine and the increase in mean arterial pressure and heart rate induced by the reduction in carotid transmural pressure in borderline hypertensive subjects were similar to those observed in normals. 4. These findings indicate that in borderline hypertensive subjects the impairment of baroreflex responsiveness is mainly due to abnormalities of autonomic regulation.

Smoking impairs baroreflex sensitivity in humans

1997 ◽  
Vol 273 (3) ◽  
pp. H1555-H1560 ◽  
Author(s):  
G. Mancia ◽  
A. Groppelli ◽  
M. Di Rienzo ◽  
P. Castiglioni ◽  
G. Parati
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Pulse Interval ◽  
Average Systolic Blood Pressure ◽  
Carotid Baroreceptor ◽  
Baroreceptor Stimulation ◽  
Finger Blood Pressure ◽  
Carotid Baroreceptor Stimulation

In 10 healthy smokers, finger blood pressure was recorded continuously for 1 h in a supine control condition and for 1 h while smoking four cigarettes, one every 15 min. Smoking increased average systolic blood pressure (+19%, P < 0.01) and its variability and reduced pulse interval (reciprocal of heart rate, -22%, P < 0.01) and its variability. Baroreflex sensitivity, as assessed by the slope of spontaneous hypertension/bradycardia or hypotension/tachycardia sequences and by the alpha-coefficient (squared ratio between pulse interval and systolic blood pressure spectral powers at 0.1 Hz) was significantly decreased (P < 0.01) during smoking, whereas there were no effects of smoking on the reflex changes in pulse interval induced by carotid baroreceptor stimulation through a neck suction device. Sham smoking by a drinking straw had no effects on any of the above parameters. Thus, when assessed in the absence of laboratory maneuvers in daily life conditions, baroreflex sensitivity is markedly impaired by smoking. This impairment may contribute to the smoking-induced increase in blood pressure and heart rate as well as to the concomitant alterations in their variability.

scholarly journals Anaesthesia and cardiopulmonary effects of tiletamine-zolazepam/xylazine/tramadol and its effects on nitric oxide, plasma endothelin, 6-keto-PGF1α and thromboxanes B2 in miniature pigs

2013 ◽  
Vol 82 (1) ◽  
pp. 103-107 ◽  
Author(s):  
De-Zhang Lu ◽  
Hong-Gang Fan ◽  
Sheng Jiang ◽  
Li-Juan Tan ◽  
Shi-Ming Yu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Negative Correlation ◽  
Positive Correlation ◽  
Miniature Pigs ◽  
Severe Bradycardia ◽  
Vasoactive Factors ◽  
Blood Pressures ◽  
The Mean

This study focused on anaesthesia and cardiopulmonary effects of tiletamine-zolazepam/xylazine/tramadol in miniature pigs and its effects on endothelium-derived vasoactive factors. A total of 14 eight-month-old Chinese experimental miniature pigs were used in this study. Tiletamine-zolazepam (3.5 mg·kg-1), xylazine (1.32 mg·kg-1) and tramadol (1.8 mg·kg-1) were administered i.m.; blood pressure and heart rate were recorded. At the same time, blood was collected through precaval vein, and nitric oxide, endothelin, 6-keto-PGF1α and thromboxanes B2 were determined by colorimetry and radioimmunoassay. The mean times to dorsal recumbency, duration of immobilization, standing and walking were 2.26 ± 0.72, 87.57 ± 9.61, 25.63 ± 12.55 and 36.70 ± 14.53 min, respectively. Blood pressure was significantly changed at 10 and 80 min (P < 0.01), and the heart rate ranged from 89 to 134 bpm without episodes of severe bradycardia or tachycardia. Significantly positive correlation was observed between endothelin, thromboxanes B2 and blood pressure as well as the heart rate (P < 0.05). There was negative correlation between PGI2 and blood pressure as well as heart rate (P < 0.05). The results showed that endothelin, 6-keto-PGF1α and thromboxanes B2 participated in the changing of cardiopulmonary parameters which were caused by tiletamine-zolazepam-xylazine-tramadol anaesthesia in miniature pigs, and the 6-keto-PGF1α, ET and TXB2 concentrations in plasma participated in the changing of blood pressures during anaesthesia. Therefore, we can recommend tiletamine-zolazepam/xylazine/tramadol for anaesthesia in pigs, and this study also contributes to the evaluation of the effect of endothelium-derived vasoactive factors during anaesthesia.

scholarly journals Influence of acepromazine on the cardiovascular actions of dobutamine in isoflurane-anesthetized horses

2011 ◽  
Vol 41 (3) ◽  
pp. 470-475 ◽  
Author(s):  
Eduardo Raposo Monteiro ◽  
Juliano Ferreira Fernandes de Souza ◽  
Gustavo Cancian Baiotto ◽  
Giuliano Moraes Figueiró ◽  
Julia da Penha Piccoli Rangel ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Infusion Rate ◽  
Experimental Treatment ◽  
Cardiovascular Actions ◽  
Blood Pressures ◽  
The Mean ◽  
To Receive

The influence of acepromazine (ACP) on the effectiveness of dobutamine (DBT) in increasing blood pressure during isoflurane (ISO) anesthesia was evaluated in six horses. On separate occasions, the horses were randomly assigned to receive NaCl 0.9% (Control), ACP 0.025mg kg-1 and ACP 0.05mg kg-1. The experimental treatment was administered prior to induction of anesthesia. Maintenance of anesthesia was performed under conditions of normocapnia with ISO in oxygen. Dobutamine was administered at progressively increasing infusion rates until mean arterial pressure (MAP) reached 70mmHg or until a maximum infusion rate of 5.0µg kg-1 min-1. Compared with baseline, DBT increased heart rate, systolic, diastolic and mean blood pressures in all treatments. However, these variables did not differ among treatments. The target MAP (70mmHg) was not reached in 2/6, 2/5 and 0/6 horses in the Control, ACP0.025 and ACP0.05 treatments, respectively. The mean dose of DBT to achieve target MAP was 3.5±1.8, 3.7±1.6 and 2.7±1.4µg kg-1 min-1 in the Control, ACP0.025 and ACP0.05 treatments, respectively (P>0.05). Under the conditions of this study, premedication with ACP does not interfere with the effectiveness of DBT in increasing blood pressure in horses anesthetized with ISO.

Carotid Baroreceptor Reflex in Normotensive and Hypertensive Subjects

1976 ◽  
Vol 51 (s3) ◽  
pp. 343s-345s ◽  
Author(s):  
G. Mancia ◽  
J. Ludbrook ◽  
A. Ferrari ◽  
L. Gregorini ◽  
R. Valentini ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Baroreceptor Reflex ◽  
The Other ◽  
Reflex Response ◽  
Arterial Blood ◽  
Carotid Baroreceptor ◽  
Normotensive Subjects ◽  
Neck Chamber ◽  
Related Increase

1. A graded decrease and increase in carotid baroreceptor activity (induced by a varying pressure in a neck chamber) caused a linearly related increase and decrease in arterial blood pressure. This occurred in both normotensive and hypertensive subjects. 2. Decrease of carotid baroreceptor activity caused a greater increase of blood pressure in normotensive than in hypertensive subjects. Increasing the activity caused changes of similar magnitude in the two groups. 3. Decrease of baroreceptor activity also caused an increase in heart rate although increasing the activity of the reflex had little effect on heart rate, particularly in normotensive subjects. Thus the carotid baroreceptor effect on blood pressure does not always reflect that on heart rate and inference of one reflex response from measurement of the other may be in error.

Can we detect the development of baroreflex sensitivity in humans between 11 and 20 years of age?

2006 ◽  
Vol 84 (12) ◽  
pp. 1275-1283 ◽  
Author(s):  
Eva Zavodna ◽  
Natasa Honzikova ◽  
Hana Hrstkova ◽  
Zuzana Novakova ◽  
Jiri Moudr ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spectral Analysis ◽  
Healthy Subjects ◽  
Baroreflex Sensitivity ◽  
Age Groups ◽  
Average Frequency ◽  
Total Group ◽  
Blood Pressures

The aim of the study was to determine changes of baroreflex sensitivity in humans between 11 and 20 years of age. Continuous 5 min blood pressure recordings using a Finapres were taken in 415 healthy subjects while in a sitting, resting position (breathing at a frequency of 0.33 Hz). Beat-by-beat values of interbeat intervals (IBI) or heart rate, and systolic and diastolic blood pressures were measured. Baroreflex sensitivity in ms/mmHg (BRS) and in mHz/mmHg (BRSf) was determined at an average frequency of 0.1 Hz by spectral analysis. BRS did not correlate with age, but BRSf significantly decreased with age (p < 0.001). BRS correlated with mean IBI (p < 0.001) in all subjects and also in the particular subgroups, but BRSf was IBI-independent. Results of multiregression equations were BRS = 1.37 – 0.56 × age (years) + 0.02 × IBI (ms) (p < 0.001 for BRS vs. age and for BRS vs. IBI); BRSf = 34.74 – 0.97 × age (years) – 0.001 × IBI (ms) (p < 0.001 only for BRS vs. age), where age was measured in years and IBI was measured in ms. The limits of BRS were estimated for the total group: 5th percentile, 3.9; 50th percentile, 9.1; and 95th percentile, 18.7 ms/mmHg; and limits for BRSf were 5th percentile, 8.5; 50th percentile, 16.4; and 95th percentile, 33.6 mHz/mmHg. We conclude that IBI-dependent BRS was unchanged in the particular age groups, but the standardization of BRS on IBI decreased with age. BRSf was IBI-independent and better reflected the development of the BRS.

Heart rate and blood pressure variability and baroreflex sensitivity in patients with acute brain injury

2005 ◽  
Vol 20 (4) ◽  
pp. 394 ◽  
Author(s):  
V. Papaioannou ◽  
M. Giannakou ◽  
N. Maglaveras ◽  
E. Sofianos ◽  
M. Giala
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Brain Injury ◽  
Blood Pressure Variability ◽  
Baroreflex Sensitivity ◽  
Acute Brain Injury

scholarly journals FRI0618-HPR EFFECTS OF MUSIC THERAPY ON PAIN, ANXIETY, AND VITAL SIGNS IN CHRONIC INFLAMMATORY RHEUMATIC DISEASES PATIENTS DURING BIOLOGICAL DRUGS INFUSION

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 914.2-914
Author(s):  
S. Boussaid ◽  
M. Ben Majdouba ◽  
S. Jriri ◽  
M. Abbes ◽  
S. Jammali ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Music Therapy ◽  
Systolic Blood Pressure ◽  
Respiratory Rate ◽  
Vital Signs ◽  
Biological Therapies ◽  
Biological Drugs ◽  
Pain Anxiety ◽  
The Mean

Background:Music therapy is based on ancient cross-cultural beliefs that music can have a “healing” effect on mind and body. Research determined that listening to music can increase comfort and relaxation, relieve pain, lower distress, reduce anxiety, improve positive emotions and mood, and decrease psychological symptoms. Music therapy has been used greatly in various medical procedures to reduce associated anxiety and pain. Patients have a high level of anxiety when they are in the hospital, this is the case of patients with rheumatic diseases who consult regularly to have intravenous infusion of biological therapies.Objectives:The purpose of this study was to examine the effectiveness of music therapy on pain, anxiety, and vital signs among patients with chronic inflammatory rheumatic diseases during intravenous infusion of biological drugs.Methods:Fifty patients were divided into two groups: The experimental group G1 (n=25) received drug infusion while lestening to soft music (30 minutes); and the control group G2 (n=25) received only drug infusion. Measures include pain, anxiety, vital signs (blood pressure, heart rate and respiratory rate). The pain was measured using visual analogic scale (VAS). The state-trait anxiety inventory (STAI) was used for measuring anxiety, low anxiety ranges from 20 to 39, the moderate anxiety ranges from 40 to 59, and high anxiety ranges from 60 to 80. Vital signs (systolic blood pressure [SBP], diastolic blood pressure [DBP], heart rate [HR], and respiratory rate [RR]) were measured before, during and immediately after the infusion.Statistical package for social sciences (SPSS) was used for analysis.Results:The mean age in G1 was 44.45 years (26-72) with a sex ratio (M/F) of 0.8. Including the 25 patients, 12 had rheumatoid arthritis, 10 had ankylosing spondylitis and 3 had psoriatic arthritis. The mean disease duration was 8 years. In G2, the mean age was 46 years (25-70) with a sex ratio (M/F) of 0.75, 12 had rheumatoid arthritis, 11 had ankylosing spondylitis and 2 had psoriatic arthritis. The mean disease duration was 7.5 years. The biological drugs used were: Infliximab in 30 cases, Tocilizumab in 12 cases and Rituximab in 8 cases.Before the infusion, the patients of experimental group had a mean VAS of 5/10±3, a mean STAI of 50.62±6.01, a mean SBP of 13.6 cmHg±1.4, a mean DBP of 8.6 cmHg±1, a mean HR of 85±10 and a mean RR of 18±3. While in control group the mean VAS was 5.5±2, the mean STAI was 50.89±5.5, the mean SBP was 13.4±1.2, the mean DBP was 8.8±1.1, the mean HR was 82±8 and the mean RR was 19±2.During the infusion and after music intervention in G1, the mean STAI became 38.35±5 in G1 versus 46.7±5.2 in G2 (p value=0.022), the mean SBP became 12.1±0.5 in G1 versus 13±1 in G2 (p=0.035), the mean DBP became 8.1±0.8 in G1 versus 8.4±0.9 in G2 (p=0.4), the mean HR became 76±9 in G1 versus 78±7 in G2 (p=0.04) and the mean RR became 17.3±2.1 in G1 versus 18.2±1.7 in G2 (p=0.39).This study found a statistically significant decrease in anxiety, systolic blood pressure and heart rate in patients receiving music interventions during biological therapies infusion, but no significant difference were identified in diastolic blood pressure and respiratory rate.Conclusion:The findings provide further evidence to support the use of music therapy to reduce anxiety, and lower systolic blood pressure and heart rate in patients with rheumatic disease during biological therapies infusion.References:[1] Lin, C., Hwang, S., Jiang, P., & Hsiung, N. (2019).Effect of Music Therapy on Pain After Orthopedic Surgery -A Systematic review and Meta-Analysis. Pain Practice.Disclosure of Interests:None declared

Variability of the haemodynamic responses to laboratory tests employed in assessment of neural cardiovascular regulation in man

1985 ◽  
Vol 69 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Gianfranco Parati ◽  
Guido Pomidossi ◽  
Agustin Ramirez ◽  
Bruno Cesana ◽  
Giuseppe Mancia
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Test Performance ◽  
Blood Pressure Response ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Cardiovascular Regulation ◽  
Pressor Test ◽  
Carotid Baroreceptor ◽  
Baroreceptor Stimulation

1. In man evaluation of neural cardiovascular regulation makes use of a variety of tests which address the excitatory and reflex inhibitory neural influences that control circulation. Because interpretation of these tests is largely based on the magnitude of the elicited haemodynamic responses, their reproducibility in any given subject is critical. 2. In 39 subjects with continuous blood pressure (intra-arterial catheter) and heart rate monitoring we measured (i) the blood pressure and heart rate rises during hand-grip and cold-pressor test, (ii) the heart rate changes occurring during baroreceptor stimulation and deactivation by injection of phenylephrine and trinitroglycerine, and (iii) the heart rate and blood pressure changes occurring with alteration in carotid baroreceptor activity by a neck chamber. Each test was carefully standardized and performed at 30 min intervals for a total of six times in each subject. 3. The results showed that the responses to any test were clearly different from one another and that this occurred in all subjects studied. For the group as a whole the average response variability (coefficient of variation) ranged from 10.2% for the blood pressure response to carotid baroreceptor stimulation to 44.2% for the heart rate response to cold-pressor test. The variability of the responses was not related to basal blood pressure or heart rate, nor to the temporal sequence of the test performance. 4. Thus tests employed for studying neural cardiovascular control in man produce responses whose reproducibility is limited. This phenomenon may make it more difficult to define the response magnitude typical of each subject, as well as its comparison in different conditions and diseases.

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