scholarly journals Blood pressure after bilateral carotid surgery

1996 ◽  
Vol 12 (4) ◽  
pp. 513-514 ◽  
Author(s):  
R. Harper ◽  
A.B. Atkinson ◽  
A.A.B. Barros D'Sa
Keyword(s):  
Blood Pressure ◽  
Carotid Surgery ◽  
Bilateral Carotid

Arterial baroreflex sensitivity and blood pressure variabilities before and after carotid surgery

1991 ◽  
Vol 69 (16) ◽  
pp. 763-768 ◽  
Author(s):  
M. Hirschl ◽  
M. M. Hirschl ◽  
D. Magometschnigg ◽  
B. Liebisch ◽  
O. Wagner ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Baroreflex Sensitivity ◽  
Carotid Surgery ◽  
Arterial Baroreflex ◽  
Before And After ◽  
Arterial Baroreflex Sensitivity

Ascending pathways mediating somatoautonomic reflexes in exercising dogs

1987 ◽  
Vol 62 (3) ◽  
pp. 1186-1191 ◽  
Author(s):  
J. W. Kozelka ◽  
G. W. Christy ◽  
R. D. Wurster
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Surgical Techniques ◽  
Arterial Occlusion ◽  
Cardiovascular Responses ◽  
Spinal Pathways ◽  
Arterial Blood ◽  
Bilateral Carotid ◽  
Dorsolateral Funiculus ◽  
Carotid Arterial

The ascending spinal pathways mediating somatocardiovascular reflexes during exercise were studied in unanesthetized dogs by placing lesions in the lumbar spinal cord. After training to run on a treadmill with hindlimbs only, 20 dogs were anesthetized and instrumented using sterile surgical techniques. To chronically record heart rate and arterial blood pressure, the aorta was cannulated via the omocervical artery. To test the intactness of descending spinal sympathetic pathways, reflex pressor responses to baroreceptor hypotension were produced by bilateral carotid arterial occlusion using pneumatic vessel occluders placed around the common carotid arteries. To generate transient ischemic exercise (120 s), a pneumatic occluder was placed around the left iliac artery. Eight to 10 days after instrumentation, blood pressure and heart rate were monitored at rest and during hindlimb running with and without simultaneous iliac arterial occlusion. The modest pressor response and tachycardia elicited by hindlimb exercise were markedly augmented by simultaneous hindlimb ischemia (i.e., iliac arterial occlusion). Lesion placement in the dorsolateral sulcus area and the dorsolateral funiculus at L2 significantly reduced the blood pressure and heart rate responses to simultaneous exercise occlusion. The cardiovascular responses to nonischemic exercise and bilateral carotid arterial occlusion were not altered by such spinal sections. It is concluded that in the dog the ascending spinal pathways mediating cardiovascular responses to ischemic exercise are located in the lateral funiculus, including the dorsolateral sulcus area and dorsolateral funiculus.

Differential effect of behavior on cardiac and vasomotor baroreflex responses

1986 ◽  
Vol 251 (1) ◽  
pp. R126-R136 ◽  
Author(s):  
C. A. Combs ◽  
O. A. Smith ◽  
C. A. Astley ◽  
E. O. Feigl
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Peripheral Circulation ◽  
Baroreceptor Reflex ◽  
Aortic Blood Flow ◽  
Renal Vasoconstriction ◽  
Bilateral Carotid Occlusion ◽  
Bilateral Carotid ◽  
Carotid Sinus Baroreflex

Bilateral carotid occlusion was performed in seven baboons during dynamic leg exercise, static arm exercise, feeding, rest, and sleep. The baroreceptor reflex effects on blood pressure, heart rate and interval, renal blood flow, and terminal aortic blood flow were determined during each behavior. The carotid sinus baroreflex increase in blood pressure and heart rate was greatest during sleep and least during exercise. The hindlimb and renal vasomotor responses followed different patterns. The baroreceptor reflex sensitivity for renal vasoconstriction was greatest during rest and least during sleep. The reflex sensitivity in the hindlimb was unaltered by behavior. Thus behavior modifies baroreceptor reflex responses in the heart and peripheral circulation in different patterns.

Cardiovascular and neuroendocrine responses to baroreceptor denervation in baboons

1990 ◽  
Vol 258 (4) ◽  
pp. R930-R938 ◽  
Author(s):  
R. E. Shade ◽  
V. S. Bishop ◽  
J. R. Haywood ◽  
C. K. Hamm
Keyword(s):  
Blood Pressure ◽  
Aortic Arch ◽  
Carotid Sinus ◽  
Cardiovascular Effects ◽  
Plasma Renin ◽  
Plasma Norepinephrine ◽  
Arterial Blood ◽  
Bilateral Carotid ◽  
Vasopressin Secretion ◽  
Blood Pressure Responses

The purpose of this study was to describe the hormonal and blood pressure responses to partial (carotid sinus) and complete (carotid sinus + aortic arch) baroreceptor denervation in baboons. Experiments were performed in eight adult male baboons maintained on a tether system for the continuous measurement of mean arterial blood pressure (MAP) and heart rate (HR). Bilateral carotid sinus denervation (CSD) immediately increased MAP from 83 +/- 2.2 to 124 +/- 7.3 mmHg. MAP gradually decreased over the next 14 days to intact levels. There were also transient decreases in HR variability and increases in blood pressure variability after CSD. Subsequent denervation of the aortic arch to produce sinoaortic denervation (SAD) resulted in another abrupt large increase in MAP followed by a small but significant increase in MAP of 11 mmHg that was maintained for up to 4 wk after SAD. The short-term variability of HR and blood pressure was chronically decreased and increased, respectively, after SAD. Plasma renin activity, vasopressin, and epinephrine were not changed from intact levels either after CSD or SAD. Plasma norepinephrine was only transiently increased by CSD and chronically elevated by 72% over intact levels after SAD. Thus CSD in the baboon does not produce a sustained increase in MAP. SAD chronically increases MAP and is associated with evidence for an increased sympathetic tone. There is no indication that either increased renin secretion or vasopressin secretion contributes to the chronic cardiovascular effects of SAD in baboons.

Pressure natriuresis during saline expansion in newborn and adult dogs

1984 ◽  
Vol 246 (6) ◽  
pp. F828-F834 ◽  
Author(s):  
L. I. Kleinman ◽  
R. O. Banks
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Perfusion Pressure ◽  
Renal Perfusion ◽  
Sodium Reabsorption ◽  
Renal Perfusion Pressure ◽  
Arterial Blood ◽  
Bilateral Carotid ◽  
Glomerular Filtrate ◽  
Pressure Natriuresis

Pressure natriuresis was studied in anesthetized saline-expanded adult (n = 10) and neonatal (n = 23) dogs. One group (protocol B) received ethacrynic acid and amiloride to block distal nephron function. Studies in the other group (protocol A) were done without diuretics. Renal arterial blood pressure was raised by bilateral carotid artery occlusion. Renal perfusion pressure was then lowered in steps by partially occluding the aorta proximal to the renal arteries. In protocol B carotid occlusion was associated with an increase in both absolute and fractional sodium excretion by adult and newborn dogs. Moreover, there was significant negative correlation (P less than 0.01) between absolute change in renal arterial pressure and change in tubular reabsorption of sodium per milliliter glomerular filtrate for both age groups. For each mmHg increase in blood pressure there was greater inhibition of sodium reabsorption in the puppy (0.55 mueq/ml glomerular filtrate) than in the adult (0.18 mueq/ml, P less than 0.05). In protocol A puppies, the inhibition of sodium reabsorption due to increases in renal perfusion pressure was less than that occurring in protocol B, indicating that some of the sodium escaping proximal nephron reabsorption was reabsorbed distally. Results of these studies indicate that during saline expansion pressure natriuresis is primarily a proximal tubular event, and the sensitivity of the proximal tubule to changes in renal arterial blood pressure is greater in the newborn than the adult kidney.

Role of the descending pressor pathway in the conscious and pentobarbital-anesthetized dog

1978 ◽  
Vol 234 (2) ◽  
pp. H152-H156
Author(s):  
G. S. Geis ◽  
G. Barratt ◽  
R. D. Wurster
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiovascular Control ◽  
Conscious Dogs ◽  
Cardiovascular Parameters ◽  
Bilateral Carotid ◽  
Before And After ◽  
Anesthetized Dogs ◽  
Conscious Animals

Resting cardiovascular parameters and the responses to bilateral carotid occlusions (BCO) were monitored in pentobarbital-anesthetized and conscious dogs before and after placing lesions in the dorsolateral funiculi at C7-C8 and after spinal transections at C7. Pre- and postlesion blood pressure (BP) and heart rate (HR) responses to exercise were also monitored. The lesions significantly attenuated the responses to BCO and decreased resting BP in anesthetized dogs. Yet neither resting HR in anesthetized or conscious dogs nor the resting BP in conscious dogs was affected by the lesions. Subsequent spinal transections significantly decreased resting HR and BP and the responses to BCO but did not affect the BP response to BCO in anesthetized dogs as compared with corresponding postlesion parameters. BP responses to exercise were significantly attenuated by the lesions, but HR responses were not affected. Since stimulation and BP studies indicated that the descending pressor pathway had been ablated, the data suggest that the pathway mediates BP and HR responses to BCO in pentobarbital-anesthetized and conscious dogs. It does not maintain resting HR in anesthetized or conscious animals, and the resting BP in conscious dogs. This pathway is important for BP responses to exercise but is not necessary for HR responses. Finally, other spinal pathways are involved in cardiovascular control.

Angiotensin II infusion increases vasopressin, ACTH, and 11-hydroxycorticosteroid secretion

1978 ◽  
Vol 234 (1) ◽  
pp. R66-R71 ◽  
Author(s):  
D. J. Ramsay ◽  
L. C. Keil ◽  
M. C. Sharpe ◽  
J. Shinsako
Keyword(s):  
Blood Pressure ◽  
Angiotensin Ii ◽  
Plasma Concentration ◽  
Plasma Renin Activity ◽  
Plasma Levels ◽  
Intravenous Infusion ◽  
Plasma Renin ◽  
Acth Secretion ◽  
Plasma Vasopressin ◽  
Bilateral Carotid

The effects of intravenous infusion of Asp1. Ile5-angiotensin II on blood pressure, plasma vasopressin, ACTH and 11-hydroxycorticosteroid levels and on plasma renin activity were studied in five trained, conscious dogs. The dogs were prepared with bilateral carotid loops. Infusion of angiotensin II at rates of 5, 10, and 20 ng/kg.min raised its plasma concentration from 23 +/- 7 to 48 +/- 8, 125 +/- 8, and 187 +/- 21 pg/ml, respectively. The lowest rate of infusion was mildly pressor, the two higher rates more so. All rates of infusion promptly increased vasopressin levels and depressed renin levels. The two higher rates also stimulated ACTH, although with a latency of 30-45 min. Since the rates of infusion of angiotensin II employed produced plasma levels within the physiological range, it is suggested that peripherally generated angiotensin II may play an important role in the regulation of vasopressin, and ACTH secretion.

Acute Device-Based Blood Pressure Reduction: Electrical Activation of the Carotid Baroreflex in Patients Undergoing Elective Carotid Surgery

Vascular ◽  
2007 ◽  
Vol 15 (2) ◽  
pp. 63-69 ◽  
Author(s):  
Jürg Schmidli ◽  
Hannu Savolainen ◽  
Friedrich Eckstein ◽  
Eric Irwin ◽  
Tim K. Peters ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Carotid Sinus ◽  
Blood Pressure Reduction ◽  
Acute Effect ◽  
Carotid Surgery ◽  
Proof Of Concept ◽  
Sinus Wall ◽  
Carotid Baroreflex ◽  
Voltage Dependent ◽  
Stimulation Of

Carotid sinus baroreceptors are involved in controlling blood pressure (BP) by providing input to the cardiovascular regulatory centers of the medulla. The acute effect of temporarily placing an electrode on the carotid sinus wall to electrically activate the baroreflex was investigated. We studied 11 patients undergoing elective carotid surgery. Baseline BP was 146+30/66±17 mm Hg and heart rate (HR) 72±7 bpm (mean ± standard deviation). An electrode was placed upon the carotid sinus and after obtaining a steady state baseline of BP and HR, an electric current was applied and increased in 1-volt increments. A voltage dependent and highly significant reduction in BP was observed which averaged 18±26* and 8.0±12 mm Hg for systolic BP and diastolic BP, respectively. Maximal reductions occurred at 4.4±1.2 V: 23±24 mm Hg*, 16±10 mm Hg* and 7±12 bpm* for systolic BP, diastolic BP and HR, respectively (= p <.05). Thus, electrical stimulation of the carotid sinus activates the carotid baroreflex resulting in a reduction in BP and HR. This presents a proof of concept for device based baroreflex modulation in acute BP regulation and adds to the available data which provide a rationale for evaluating this system in the context of chronic BP reduction in hypertensive patients.

Abnormal regulation of the sympathoadrenal system in deoxycorticosterone acetate – salt hypertensive rats

1987 ◽  
Vol 65 (8) ◽  
pp. 1605-1614 ◽  
Author(s):  
J. de Champlain ◽  
M. Bouvier ◽  
G. Drolet
Keyword(s):  
Blood Pressure ◽  
Adrenal Medulla ◽  
Close Correlation ◽  
Carotid Occlusion ◽  
Sympathoadrenal System ◽  
Hypertensive Rats ◽  
Functional Balance ◽  
Bilateral Carotid ◽  
Β Receptor ◽  
Conscious Animals

With the use of circulating norepinephrine (NE) and epinephrine (E) levels, the sympathoadrenal activity as well as its local modulation by adrenoceptors were studied in normotensive (NT) and DOCA–salt hypertensive (HT) rats. In anesthetized hypertensive rats, plasma NE levels were higher, whereas in conscious animals both NE and E levels were found to be increased, suggesting an increased basal sympathoadrenal tone in these animals. The finding of a close correlation between blood pressure levels and NE levels suggests that the elevation of blood pressure may be linked to sympathetic system activity in this experimental model of hypertension. The reactivity of the sympathoadrenal system was also found to be increased in DOCA HT rats. Following a bilateral carotid occlusion of 1 min, which specifically activates the adrenal medulla, the elevation of E levels was found to be potentiated in intact or vagotomized HT rats. Moreover, in response to prolonged or acute hypotension in anesthetized and conscious animals, the elevation in plasma NE and E levels was found to be markedly potentiated in DOCA HT rats. The local modulating adrenoceptor-mediated mechanisms of the sympathoadrenal system appeared to be altered in this model of hypertension. Although it was possible to demonstrate that the E response to carotid occlusion can be greatly potentiated by administration of an α2-antagonist (yohimbine) and completely abolished by an α2-agonist (clonidine) in NT rats, the E response was found to be unaffected by the same treatments in HT rats, suggesting a reduced sensitivity in the α2-mediated inhibitory modulation of the adrenal medulla. Moreover, the acute treatment with a β-blocker (sotalol) lowered circulating NE levels and blood pressure only in HT rats, suggesting the possibility of a more sensitive β-receptor-mediated presynaptic facilitatory mechanism on sympathetic fibers of these animals. Finally, it was observed that the functional balance which exists between the activities of sympathetic fibers and the adrenal medulla in normotensive animals appears to be impaired in DOCA HT rats. In conclusion, the present studies suggest that the increased sympathoadrenal tone and reactivity may be due, in part, to a variety of dysfunctions in local adrenoceptor modulatory mechanisms of the sympathoadrenal system in DOCA hypertensive rats.

Sign in / Sign up

Export Citation Format

Share Document