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.

Acute manipulations of plasma volume alter arterial pressure responses during Valsalva maneuvers

1999 ◽  
Vol 86 (6) ◽  
pp. 1852-1857 ◽  
Author(s):  
Janice M. Fritsch-Yelle ◽  
Victor A. Convertino ◽  
Todd T. Schlegel
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Phase Ii ◽  
Plasma Volume ◽  
Diastolic Pressure ◽  
Valsalva Maneuver ◽  
Isotonic Saline ◽  
Systolic Pressure ◽  
Cardiovascular Responses ◽  
Phase Iii

The effects of changes in blood volume on arterial pressure patterns during the Valsalva maneuver are incompletely understood. In the present study we measured beat-to-beat arterial pressure and heart rate responses to supine Valsalva maneuvers during normovolemia, hypovolemia induced with intravenous furosemide, and hypervolemia induced with ingestion of isotonic saline. Valsalva responses were analyzed according to the four phases as previously described (W. F. Hamilton, R. A. Woodbury, and H. T. Harper, Jr. JAMA 107: 853–856, 1936; W. F. Hamilton, R. A. Woodbury, and H. T. Harper, Jr. Am. J. Physiol. 141: 42–50, 1944). Phase I is the initial onset of straining, which elicits a rise in arterial pressure; phase II is the period of straining, during which venous return is impeded and pressure falls (early) and then partially recovers (late); phase III is the initial release of straining; and phase IV consists of a rapid “overshoot” of arterial pressure after the release. During hypervolemia, early phase II arterial pressure decreases were significantly less than those during hypovolemia, thus making the response more “square.” Systolic pressure hypervolemic vs. hypovolemic falls were −7.4 ± 2.1 vs. −30.7 ± 7 mmHg ( P = 0.005). Diastolic pressure hypervolemic vs. hypovolemic falls were −2.4 ± 1.6 vs. −15.2 ± 2.6 mmHg ( P = 0.05). A significant direct correlation was found between plasma volume and phase II systolic pressure falls, and a significant inverse correlation was found between plasma volume and phase III-IV systolic pressure overshoots. Heart rate responses to systolic pressure falls during phase II were significantly less during hypovolemia than during hypervolemia (0.7 ± 0.2 vs. 2.82 ± 0.2 beats ⋅ min−1 ⋅ mmHg−1; P = 0.05) but were not different during phase III-IV overshoots. We conclude that acute changes in intravascular volume from hypovolemia to hypervolemia affect cardiovascular responses, particularly arterial pressure changes, to the Valsalva maneuver and should be considered in both clinical and research applications of this maneuver.

Effects of Clonidine and Hydrochlorothiazide on the Cardiovascular Response to Mental Stress in Adolescent Hypertension

1982 ◽  
Vol 63 (s8) ◽  
pp. 455s-458s ◽  
Author(s):  
Bonita Falkner ◽  
Gaddo Onesti ◽  
Melton B. Affrime ◽  
David T. Lowenthal
Keyword(s):  
Heart Rate ◽  
Essential Hypertension ◽  
Mental Stress ◽  
Diastolic Pressure ◽  
Cardiovascular Response ◽  
Systolic Pressure ◽  
Cardiovascular Responses ◽  
Plasma Noradrenaline ◽  
Lower Plasma ◽  
Adrenergic Activity

1. The effects of clonidine and hydrochlorothiazide on the cardiovascular responses to mental stess were compared in 29 adolescents with essential hypertension. 2. Clonidine therapy was associated with lower diastolic pressures, heart rate and noradrenaline in response to mental stress. By contrast, hydrochlorothiazide resulted in the reduction of systolic pressure only. The mental stress testing produced a greater absolute diastolic pressure response and higher plasma noradrenaline on hydrochlorothiazide therapy. 3. Juveniles with essential hypertension may be more sensitive to central control of blood pressure and more resistant to diuretics. 4. The reduced diastolic pressure and heart rate response to central stimuli during clonidine therapy may be related to decreased adrenergic activity, as indicated by lower plasma noradrenaline.

Role of paraventricular and supraoptic nuclei in central cardiovascular regulation in the cat

1980 ◽  
Vol 239 (1) ◽  
pp. R137-R142 ◽  
Author(s):  
J. Ciriello ◽  
F. R. Calaresu
Keyword(s):  
Heart Rate ◽  
Cardiovascular Responses ◽  
Inhibitory Influence ◽  
Sympathetic Nervous Systems ◽  
Aortic Depressor Nerve ◽  
Bilateral Lesions ◽  
Alpha Chloralose ◽  
Supraoptic Nuclei ◽  
Stimulation Of

To investigate the role of the paraventricular (PAH) and supraoptic (SON) nuclei in regulation of the cardiovascular system experiments were done in 26 cats anesthetized with alpha-chloralose, paralyzed, and artificially ventilated. Electrical stimulation of histologically verified sites in the region of the PAH and SON elicited increases in arterial pressure in bilaterally vagotomized animals and increases in heart rate both in spinal (C2) animals and in animals bilaterally vagotomized, In addition, stimulation of either the PAH or SON inhibited the reflex vagal bradycardia elicited by stimulation of the carotid sinus nerve (CSN) and bilateral lesions of these areas increased the magnitude of the response. On the other hand, stimulation and lesions of these hypothalamic regions did not alter the magnitude of the cardiovascular responses to stimulation of the aortic depressor nerve. These results demonstrate that stimulation of the PAH and SON elicit cardiovascular responses due to reciprocal changes in activity of the parasympathetic and sympathetic nervous systems and that these structures maintain a tonic inhibitory influence on the heart rate component of the CSN reflex.

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.

Interactions between brain acetylcholine and prostaglandins in control of vasopressin release

1991 ◽  
Vol 261 (2) ◽  
pp. R420-R426
Author(s):  
M. Inoue ◽  
J. T. Crofton ◽  
L. Share
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Cardiovascular Responses ◽  
Vasopressin Release ◽  
Arterial Blood ◽  
Plasma Vasopressin ◽  
Vasopressin Secretion ◽  
Stimulation Of

We have examined in conscious rats the interaction between centrally acting prostanoids and acetylcholine in the stimulation of vasopressin secretion. The intracerebroventricular (icv) administration of carbachol (25 ng) resulted in marked transient increases in the plasma vasopressin concentration and mean arterial blood pressure and a transient reduction in heart rate. Central cyclooxygenase blockade by pretreatment icv with either meclofenamate (100 micrograms) or indomethacin (100 micrograms) virtually completely blocked these responses. Prostaglandin (PG) D2 (20 micrograms icv) caused transient increases in the plasma vasopressin concentration (much smaller than after carbachol) and heart rate, whereas mean arterial blood pressure rose gradually during the 15-min course of the experiment. Pretreatment with the muscarinic antagonist atropine (10 micrograms icv) decreased the peak vasopressin response to icv PGD2 by approximately one-third but had no effect on the cardiovascular responses. We conclude that the stimulation of vasopressin release by centrally acting acetylcholine is dependent on increased prostanoid biosynthesis. On the other hand, stimulation of vasopressin release by icv PGD2 is partially dependent on activation of a cholinergic pathway.

Reflex cardiovascular response to exercise is modulated by circulating vasopressin

1992 ◽  
Vol 263 (5) ◽  
pp. R1104-R1109 ◽  
Author(s):  
C. L. Stebbins
Keyword(s):  
Heart Rate ◽  
Receptor Antagonist ◽  
Cardiovascular Response ◽  
Regional Blood Flow ◽  
Plasma Concentrations ◽  
Cardiovascular Responses ◽  
Vascular Effect ◽  
Ganglionic Blockade ◽  
Hindlimb Muscles ◽  
Before And After

Peripheral vasopressin (AVP) can act centrally to sensitize the arterial baroreflex and/or peripherally to attenuate regional blood flow by a direct vascular effect. Because plasma concentrations of AVP increase during exercise, this study examined the possibility that AVP is capable of modulating the reflex cardiovascular response to static muscle contraction. Thus, in anesthetized cats, the pressor [mean arterial pressure (MAP)], myocardial contractile (dP/dt), and heart rate responses to 30-45 s of electrically induced static contraction of the hindlimb muscles were compared before and after intravenous injection of the V1 receptor antagonist d[CH2)5Tyr(Me)]-AVP (V1-x, n = 7), V1-x plus the V2 receptor antagonist [d(CH2)5,D-Phe2,Ile4,Arg8,Ala9]vasopressin (V2-x, n = 5), or the ganglionic blocker hexamethonium chloride (n = 5). In three additional cats, the contraction-induced cardiovascular response was monitored before and after injection of V1-x + V2-x and after hexamethonium. Subsequent to treatment with V1-x, the MAP and dP/dt responses to contraction were augmented by 18 +/- 5 and 22 +/- 10%, respectively (P < 0.05). After injection of V1-x + V2-x, the MAP and dP/dt responses were augmented to a similar extent (32 +/- 6 and 40 +/- 17%, respectively; P < 0.05). However, there was no difference in the magnitude of augmentation of these responses between the two conditions. The heart rate response was not altered by either treatment. Ganglionic blockade eliminated the cardiovascular responses to contraction. Last, when the pressor and contractile responses to contraction were initially augmented by administration of V1-x + V2-x, subsequent ganglionic blockade abolished the entire cardiovascular response.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Effect of regional myocardial ischemia on cardiac pump performance during exercise

1978 ◽  
Vol 234 (2) ◽  
pp. H157-H162
Author(s):  
L. D. Horwitz ◽  
D. F. Peterson ◽  
V. S. Bishop
Keyword(s):  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular Pressure ◽  
Left Ventricular ◽  
Adrenergic Stimulation ◽  
Circumflex Coronary Artery ◽  
Pump Performance ◽  
Regional Myocardial Ischemia ◽  
Exercise Hemodynamics ◽  
Stimulation Of

The effect of brief periods of regional ischemia upon left ventricular pump performance was studied in nine dogs standing quietly at rest and during running exercise on a treadmill. Transient occlusions of the left circumflex coronary artery resulted in increase in heart rate at rest (+30 beats/min) but not during exercise. Other changes due to occlusion were similar at rest and during exercise and included decreases in stroke volume (-25% standing, -23% running); in dP/dt max, the maximum first derivative of the left ventricular pressure (-20% standing or running); and in left ventricular peak systolic pressure (-13% standing, -21% running); and rises in left ventricular end-diastolic pressure (+4.5 mmHg standing, +6.3 mmHg running). Cardiac output was unchanged by occlusions at rest but fell (-18%) during occlusions while the dogs were running. Propranolol reduced absolute levels of cardiac performance during exercise occlusions but had no effect at rest. Inotropic agents with ischemia had some effects at rest but did not alter exercise hemodynamics. It is concluded that integrated left ventricular function during ischemia is not impaired by exercise, probably because of beta-adrenergic stimulation of nonischemic myocardium.

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).

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