Pitfalls in the assessment of cardiovascular reflexes in patients with sympathetic failure but intact vagal control

1989 ◽  
Vol 76 (5) ◽  
pp. 523-528 ◽  
Author(s):  
J. J. van Lieshout ◽  
W. Wieling ◽  
K. H. Wesseling ◽  
J. M. Karemaker
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Time Course ◽  
Blood Pressure Response ◽  
Stress Test ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Valsalva Manoeuvre ◽  
Cardiovascular Reflexes ◽  
Vagal Control

1. Two patients are described who presented with orthostatic hypotension as the main symptom. The diagnosis was sympathetic failure with intact vagal control. 2. Unusual test result's were obtained. Assessment of the integrity of the total baroreflex arc by the Valsalva manoeuvre measuring only heart rate changes proved impossible, since the magnitude and time course of the heart rate response were normal notwithstanding the presence of a blood pressure response typical of sympathetic failure. 3. Sustained handgrip, cold pressor test and mental stress test all could induce a rise in blood pressure, despite the presence of sympathetic vasomotor lesions, but only when accompanied by a rise in heart rate. Efferent parasympathetic blockade by atropine, resulting in an increase in heart rate, was also accompanied by a substantial rise in blood pressure. These findings seem to result from a heart rate rise dependent increase in cardiac output unopposed by reflex vasodilatation. 4. In these patients the only baroreflex way to control blood pressure is by varying heart rate. This condition can be evaluated only if blood pressure and heart rate are measured on a beat-by-beat basis.

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.

Evidence of Parasympathetic Activity of the Angiotensin Converting Enzyme Inhibitor, Captopril, in Normotensive Man

1985 ◽  
Vol 68 (1) ◽  
pp. 49-56 ◽  
Author(s):  
B. C. Campbell ◽  
Alessandra Sturani ◽  
J. L. Reid
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Enzyme Inhibitor ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Pressure Change ◽  
Parasympathetic Activity ◽  
Valsalva Manoeuvre ◽  
The Difference ◽  
Normal Increase

1. Captopril (50 mg orally) produced a significant fall in systolic and diastolic blood pressure in six normotensive sodium replete subjects, without a rise in heart rate. 2. On captopril, there was no change in the expected normal increase in heart rate on standing. Supine plasma noradrenaline was not reduced by captopril and normal postural increases were maintained. 3. Atropine (0.04 mg/kg i.v.) reduced the difference in blood pressure change between captopril and placebo. 4. Facial immersion in water produced a bradycardia. This change was abolished by atropine and attenuated both by captopril and edrophonium (10 mg i.V.), a cholinesterase inhibitor. 5. Lying down after 6 min standing produced an immediate transient tachycardia, which was abolished by atropine and attenuated by captopril. 6. Blood pressure and heart rate rose after a cold pressor test on both captopril and placebo. 7. The tachycardia during the Valsalva manoeuvre was inhibited by edrophonium and to a lesser extent by captopril. The effects of captopril and edrophonium were additive. 8. Parasympathetic activity of captopril may contribute to its haemodynamic profile.

scholarly journals Heat stress attenuates the increase in arterial blood pressure during the cold pressor test

2010 ◽  
Vol 109 (5) ◽  
pp. 1354-1359 ◽  
Author(s):  
Jian Cui ◽  
Manabu Shibasaki ◽  
David A. Low ◽  
David M. Keller ◽  
Scott L. Davis ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heat Stress ◽  
Arterial Blood Pressure ◽  
Blood Pressure Response ◽  
Cold Pressor Test ◽  
Thermal Conditions ◽  
Cold Pressor ◽  
Pressor Test ◽  
Arterial Blood

The mechanisms by which heat stress impairs the control of blood pressure leading to compromised orthostatic tolerance are not thoroughly understood. A possible mechanism may be an attenuated blood pressure response to a given increase in sympathetic activity. This study tested the hypothesis that whole body heating attenuates the blood pressure response to a non-baroreflex-mediated sympathoexcitatory stimulus. Ten healthy subjects were instrumented for the measurement of integrated muscle sympathetic nerve activity (MSNA), mean arterial blood pressure (MAP), heart rate, sweat rate, and forearm skin blood flow. Subjects were exposed to a cold pressor test (CPT) by immersing a hand in an ice water slurry for 3 min while otherwise normothermic and while heat stressed (i.e., increase core temperature ∼0.7°C via water-perfused suit). Mean responses from the final minute of the CPT were evaluated. In both thermal conditions CPT induced significant increases in MSNA and MAP without altering heart rate. Although the increase in MSNA to the CPT was similar between thermal conditions (normothermia: Δ14.0 ± 2.6; heat stress: Δ19.1 ± 2.6 bursts/min; P = 0.09), the accompanying increase in MAP was attenuated when subjects were heat stressed (normothermia: Δ25.6 ± 2.3, heat stress: Δ13.4 ± 3.0 mmHg; P < 0.001). The results demonstrate that heat stress can attenuate the pressor response to a sympathoexcitatory stimulus.

Defective Reflex Control of Heart Rate in Dialysis Patients: Evidence for an Afferent Autonomic Lesion

1982 ◽  
Vol 63 (3) ◽  
pp. 285-292 ◽  
Author(s):  
C. Zoccali ◽  
M. Ciccarelli ◽  
Q. Maggiore
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Autonomic Function ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Valsalva Manoeuvre ◽  
Dialysis Patients ◽  
Pressor Test ◽  
Reflex Control ◽  
Deep Breathing Test

1. To localize the site of autonomic abnormality in patients undergoing haemodialysis, tests of overall autonomic function based on either changes in blood pressure (posture, sustained handgrip) or heart rate (Valsalva manoeuvre, 30:15 ratio, deep breathing test) were used. Integrity of the sympathetic efferent arc was examined by using the cold pressor test and the parasympathetic efferent arc by the atropine test. Eighteen patients and 12 control subjects were studied. 2. Changes in blood pressure on standing, sustained handgrip and in the cold pressor test were the same in the two groups. 3. In contrast, 11 patients had abnormal results in at least two of the three heart-rate-based tests. 4. Three of the 11 dialysis patients with evidence of autonomic involvement showed abnormal responses to atropine, indicating an efferent parasympathetic lesion, whereas the majority had a normal response to the atropine test, suggesting an afferent lesion only. 5. Evidence of autonomic involvement was not associated with hypertension nor confined to patients with dialysis hypotension.

Effects of the cold pressor test on short-term fluctuations of finger arterial blood pressure and heart rate in normal subjects

1993 ◽  
Vol 3 (5) ◽  
pp. 303-310 ◽  
Author(s):  
Frank Weise ◽  
Dominique Laude ◽  
Arlette Girard ◽  
Philippe Zitoun ◽  
Jean-Philippe Siché ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Normal Subjects ◽  
Short Term ◽  
Pressor Test ◽  
Arterial Blood

Power Spectral Analysis of Heart Rate and Diastolic Blood Pressure Variability in Migraine with and Without Aura

Cephalalgia ◽  
1997 ◽  
Vol 17 (7) ◽  
pp. 756-760 ◽  
Author(s):  
G Pierangeli ◽  
P Parchi ◽  
G Barletta ◽  
M Chiogna ◽  
E Lugaresi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Spectral Analysis ◽  
Diastolic Blood Pressure ◽  
Blood Pressure Variability ◽  
Power Spectral Analysis ◽  
Cardiovascular Responses ◽  
Valsalva Manoeuvre ◽  
Cardiovascular Reflexes ◽  
Power Spectral

Autonomic function in migraineurs during headache-free periods was studied by means of cardiovascular reflexes and power spectral analysis of heart rate and diastolic blood pressure variability. We examined 56 patients: 37 suffering from migraine without aura and 19 from migraine with aura. Cardiovascular responses to the tilt test and Valsalva manoeuvre showed a normal function of the overall baroreceptor reflex arc. Normal heart rate responses to valsalva manoeuvre and deep breathing suggested an intact parasympathetic function. Power spectral analysis of both heart rate and diastolic blood pressure variability in basal conditions and during orthostatic test showed similar sympathovagal interactions modulating cardiovascular control in migraine patients and in controls.

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