Cardiovascular Reflexes in Parkinsonism

1971 ◽  
Vol 41 (1) ◽  
pp. 63-67 ◽  
Author(s):  
J. L. Reid ◽  
D. B. Calne ◽  
C. F. George ◽  
C. Pallis ◽  
S. D. Vakil
Keyword(s):  
Blood Pressure ◽  
Pulse Rate ◽  
Reflex Activity ◽  
Cardiovascular Reflexes ◽  
Cardiovascular Reflex ◽  
Head Up Tilt ◽  
Valsalva's Manoeuvre

1. Cardiovascular reflex activity has been studied in thirty Parkinsonian patients, none of who had received levodopa or sympatholytic drugs. 2. Changes in blood pressure and pulse rate in response to Valsalva's manoeuvre and head-up tilt were investigated by intra-arterial recording. 3. Cardiovascular reflex function deteriorated with advancing age, but there was no correlation with either the duration or the severity of the Parkinsonism. 4. These results are discussed in relation to previous reports of hypotension in Parkinsonism.

Viscerosensory-cardiovascular reflexes: altered baroreflex sensitivity in irritable bowel syndrome

2005 ◽  
Vol 289 (4) ◽  
pp. R970-R976 ◽  
Author(s):  
Patrick P. J. van der Veek ◽  
Cees A. Swenne ◽  
Hedde van de Vooren ◽  
Annelies L. Schoneveld ◽  
Roberto Maestri ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Irritable Bowel Syndrome ◽  
Baroreflex Sensitivity ◽  
Cardiovascular Reflexes ◽  
Healthy Controls ◽  
Rectal Balloon ◽  
Arterial Blood ◽  
Cardiovascular Reflex ◽  
Irritable Bowel ◽  
Intense Stimulation

Animal studies have demonstrated that visceral afferent stimulation alters autonomic cardiovascular reflexes. This mechanism might play an important role in the pathophysiology of conditions associated with visceral hypersensitivity, such as irritable bowel syndrome (IBS). As such, studies in humans are lacking, we measured viscerosensory-cardiovascular reflex interactions in IBS patients and healthy controls. Systolic blood pressure (SBP), heart rate (HR), and arterial baroreflex sensitivity (BRS) were studied in 87 IBS patients and 36 healthy controls under baseline conditions and during mild (15 mmHg) and intense (35 mmHg) visceral stimulation by rectal balloon distension. BRS was computed from continuous ECG and arterial blood pressure signals (Finapres-method) during 5-min periods of 15-min metronome respiration. Baseline SBP and HR were not different between patients and controls. In both groups, SBP increased similarly during rectal stimulation, whereas HR decreased during mild and increased intense stimulation. BRS was significantly higher in patients compared with controls at baseline (7.9 ± 5.4 vs. 5.7 ± 3.7 ms/mmHg, P = 0.03) and increased significantly in both groups during mild stimulation. This increase persisted in controls during intense stimulation, but BRS returned to baseline in patients. BRS was not significantly different between groups during rectal distension. This study demonstrates the presence of a viscerosensory-cardiovascular reflex in healthy individuals and in IBS patients. The increased BRS in IBS patients at baseline may either be a training-effect (frequent challenging of the reflex) or reflects altered viscerosensory processing at the nucleus tractus solitarii.

Sympathetic Responses to Valsalva's Manoeuvre Following Bed Rest

2003 ◽  
Vol 28 (3) ◽  
pp. 342-355 ◽  
Author(s):  
J. Kevin Shoemaker ◽  
Cynthia S. Hogeman ◽  
Lawrence I. Sinoway
Keyword(s):  
Blood Pressure ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Bed Rest ◽  
Pressure Control ◽  
Burst Frequency ◽  
Nerve Activity ◽  
Head Up Tilt ◽  
Valsalva's Manoeuvre

The purpose of this study was to examine whether 14 days of head-down tilt bed rest (HDBR) alters autonomic regulation during Valsalva's manoeuvre (VM) and if this would predict blood pressure control during a 60° head-up tilt (HUT) test. To examine autonomic control of blood pressure, we measured the changes in systolic (ΔSBP) and diastolic (ΔDBP) blood pressure between baseline and the early straining (Phase IIE) period of VM (20 sec straining to 40 mmHg; N = 7) in conjunction with changes in muscle sympathetic nerve activity (MSNA; microneurography) burst frequency (B/min) and total activity (%Δ) from baseline over the 20-sec straining period. MSNA data were successfully recorded from 6 of the 7 individuals. The averaged responses from three repeated VMs performed in the supine position were compared between the pre- and post-HDBR tests. Compared with the pre-HDBR test, a greater reduction in SBP, DBP, and MAP was observed during Phase IIE following HDBR, p < 0.05. The increase in MSNA burst frequency during straining was augmented in the post- compared with the pre-HDBR test, p < 0.0001, as was the Phase IV blood pressure overshoot, p < 0.05. Although all subjects completed the 20-min pre-HDBR tilt test without evidence of hypotension or orthostatic intolerance, the post-HDBR test was stopped early in 5 of the 7 subjects due to systolic hypotension. The responses during the VM suggest that acute autonomic adjustments to rapid blood pressure changes are preserved after bed rest. Furthermore, MSNA and blood pressure responses during VM did not predict blood pressure control during orthostasis following HDBR. Key words: muscle sympathetic nerve activity, blood pressure, orthostatic tolerance, head-up tilt

Cardiovascular Reflexes in Patients With Vascular Headache

Cephalalgia ◽  
1992 ◽  
Vol 12 (6) ◽  
pp. 360-364 ◽  
Author(s):  
Rosario Martín ◽  
Cristina Ribera ◽  
Jose Manuel Moltó ◽  
Carolina Ruiz ◽  
Luz Galiano ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Healthy Volunteers ◽  
Migraine Without Aura ◽  
Autonomic Function ◽  
Heart Rate Response ◽  
Cardiovascular Reflexes ◽  
Deep Breathing ◽  
Vascular Headache ◽  
Cardiovascular Reflex

We have investigated the autonomic function of 75 patients with migraine by examining cardiovascular reflex function. The results were compared with those of 78 healthy volunteers. Measurements were made between attacks. Patients with migraine showed a smaller heart-rate response to deep breathing but a greater heart-rate response and higher blood pressure to standing when compared to controls. Migraine patients had a higher percentage of established sympathetic lesions (51% vs 17%) and severe (25% vs 5%) or atypical (24% vs 11.5%) global autonomic dysfunction. No significant differences were found among patients with migraine with aura, migraine without aura, and migraine with prolonged aura. Our findings indicate that patients with migraine have sympathetic hypofunction.

Cardiovascular reflexes following lesions in medullary reticular formation

1965 ◽  
Vol 208 (2) ◽  
pp. 283-288 ◽  
Author(s):  
John W. Manning
Keyword(s):  
Blood Pressure ◽  
Reticular Formation ◽  
Tissue Injury ◽  
Cardiac Activity ◽  
Cardiovascular Reflexes ◽  
Medullary Reticular Formation ◽  
Cardiovascular Reflex ◽  
Vascular Reflex ◽  
Inferior Olivary ◽  
Stimulation Of

In 19 anesthetized cats acute destruction of large portions of the medullary reticular formation was achieved with the aid of a radio-frequency lesion maker. Midline structures were spared by confining the lesions to the dorsolateral medulla. Tissue injury extended from a level rostral to the inferior olivary complex to the obex. These lesions in the medullary vasomotor area did not alter significantly the cardiovascular reflex adjustments to bilateral occlusion of the carotid arteries or to the stimulation of the central end of the cut sciatic nerve. In addition, an increase in contractile force, heart rate, and blood pressure evoked by stimulation of pressor areas in the posterior hypothalamus could be obtained following the lesions. The preparations were critically dependent upon supramedullary connections to maintain vascular tone and circulatory reflex adjustments, for decerebration in the lesioned animal brought about a reduction in blood pressure and a loss of vascular reflex responses. These findings suggest that supramedullary centers exert tonic as well as phasic influences on vascular and cardiac activity that is independent of the medullary vasomotor area.

Vasopressin Secretion in Diabetic Subjects with and without Autonomic Neuropathy: Responses to Osmotic and Postural Stimulation

1989 ◽  
Vol 77 (6) ◽  
pp. 589-597 ◽  
Author(s):  
W. Reid ◽  
D. J. Ewing ◽  
S. L. Lightman ◽  
D. Eadington ◽  
T. D. M. Williams ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Weight ◽  
Autonomic Neuropathy ◽  
Plasma Osmolality ◽  
Normal Subjects ◽  
Cardiovascular Reflex ◽  
Head Up Tilt ◽  
Vasopressin Secretion ◽  
Osmotic Stimulus

1. The release of arginine vasopressin (AVP) after an osmotic stimulus and head-up tilt was assessed in diabetic subjects with and without autonomic neuropathy 2. Six diabetic subjects with (DAN +ve) and five without (DAN − ve) evidence of autonomic neuropathy and five normal subjects were infused with 5% (w/v) NaCl at a rate of 0.05 ml min−1 kg−1 body weight for 120 min. Blood pressure, heart rate and plasma AVP were measured over this period 3. Seven DAN +ve, six DAN −ve and six normal subjects were tilted head-up to 45° for 120 min. Blood pressure, heart rate and plasma AVP were measured during the study 4. Infusion of 5% (w/v) NaCl produced appropriate rises in plasma osmolality and plasma AVP levels which did not differ between the three groups, confirming the normal osmotic release of AVP in the diabetic subjects 5. During head-up tilt, there were no differences in AVP responses between the three groups, despite a major hypotensive stimulus in the DAN + ve group 6. We conclude that osmotic release of AVP is normal in diabetes, but that cardiovascular release of AVP is impaired in diabetic subjects with cardiovascular reflex evidence of autonomic neuropathy, reflecting an afferent defect.

The Effect of the Methionine Enkephalin Analogue DAMME on the Vasopressin Response to Tilt in Man

1980 ◽  
Vol 59 (6) ◽  
pp. 501-503 ◽  
Author(s):  
S. L. Lightman ◽  
Mary L. Forsling
Keyword(s):  
Blood Pressure ◽  
Pulse Rate ◽  
Plasma Volume ◽  
Arginine Vasopressin ◽  
Pressure Pulse ◽  
Volume Changes ◽  
Methionine Enkephalin ◽  
Head Up Tilt ◽  
Plasma Arginine

1. Infusion of the methionine enkephalin analogue DAMME (Sandoz) inhibits the rise in plasma arginine vasopressin after a 65° head-up tilt. 2. DAMME does not significantly affect the blood pressure, pulse rate or plasma volume changes produced by tilt.

The Action of L(-)-Dopa on Baroreflexes in Parkinsonism

1972 ◽  
Vol 43 (6) ◽  
pp. 851-859 ◽  
Author(s):  
J. L. Reid ◽  
D. B. Calne ◽  
C. F. George ◽  
S. D. Vakil
Keyword(s):  
Blood Pressure ◽  
Pressor Response ◽  
Horizontal Position ◽  
Postural Change ◽  
Arterial Blood ◽  
Cardiovascular Reflex ◽  
Significant Impairment ◽  
The Central Nervous System ◽  
Valsalva's Manoeuvre ◽  
Blood Pressure Responses

1. The intra-arterial blood pressure responses to Valsalva's manoeuvre and postural change were investigated as indices of cardiovascular reflex activity in seventeen Parkinsonian patients on maximally tolerated doses of l(-)-dopa (levodopa) and repeated in nine patients on levodopa with an extracerebral decarboxylase inhibitor, l-alpha methyldopahydrazine. The results were compared with control pretreatment responses. 2. There was significant impairment of the pressor response to Valsalva's manoeuvre on levodopa, which returned to control values after the addition of l-alpha methyldopahydrazine. 3. The systolic, diastolic and mean arterial pressures measured in a horizontal position during treatment with levodopa, with and without l-alpha methyldopahydrazine, were significantly lower than pretreatment values. 4. It is concluded that the impairment of baroreflex function by levodopa is mediated, at least in part, at the periphery. In contrast, mechanisms operating within the central nervous system contribute to the lowering of blood pressure recorded in the horizontal position in patients receiving levodopa.

Anatomical and Morphological study of the Heart's Chambers and valves in Iraqi ducks Anser platyrhuncha

2019 ◽  
Vol 43 (1) ◽  
pp. 21-25
Author(s):  
Mohammed Senna Hassan
Keyword(s):  
Blood Pressure ◽  
Anterior Chamber ◽  
High Blood Pressure ◽  
Pulse Rate ◽  
Morphological Study ◽  
Heart Valves ◽  
Simple Manner ◽  
High Pulse ◽  
The Right ◽  
High Pulse Rate

   Twenty Iraqi ducks hearts ( 10 male and 10 female ) have been  used for   demonstration  and illustration of heart's valves  and chambers  as well as  anatomical   and morphological site of view to explain what modifications had been take place for ducks heart  to perform  his normal life at the  circumstances  of  high  blood  pressure  and  pulse  rate. The heart  which has distinctly pointed  apex  was  built   in simple  manner located  in a transparent  taught  heart  pericardial  sac. It   was pyramidal in shape  externally  and  has a longitudinal  salcus  passing  to the  right  side, the  anterior of  the   heart  is  divided  into two  unequal  anterior  chamber  similar  to  those of mammalian  hear  .The heart valves are modified  in  order to  minimize  the  fraction  that occur as a result of  high  blood  pressure  and  pulse  rate  of  the  duck  heart , also  the  muscular  trabeculae   replace  the  chordate  tendineae  , which  were  present in the  mammalian    heart  in order to  minimize  the  fraction  resulting  from high  pulse  rate..    

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