A comparison of non-invasive continuous finger blood pressure measurement (Finapres) with intra-arterial pressure during prolonged head-up tilt

Petersen, Mark E.V.; Williams, Timothy R.; Sutton, Richard

doi:10.1093/oxfordjournals.eurheartj.a060791

Cited by 86 publications

(51 citation statements)

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“…Although arterial pressure waveforms change with head-up tilt, noninvasive plethysmography correlates very well with intra-arterial pressure recordings during head-up tilt. 28 A direct measurement of MCA pressure is impossible without very invasive procedures that would, in themselves, affect the interpretation of our work. Because original work with the model 23,25 used MCA pressure derived by use of Finapres monitoring as the input parameter and assumed that fluctuations in perfusion pressure were reflected, in the main, by MCA pressure fluctuations, we believe that it is important that we use MCA pressure when calculating ARI values.…”

Section: Discussionmentioning

confidence: 97%

Cerebral Autoregulatory Responses to Head-Up Tilt in Normal Subjects and Patients With Recurrent Vasovagal Syncope

Carey

Manktelow²,

Panerai³

et al. 2001

Circulation

113

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Background-The effect of orthostatic stress on dynamic cerebral autoregulation (CA) in normal subjects and patients with recurrent vasovagal syncope (VVS) is unclear. This study assessed the dynamic CA responses of both groups to head-up tilt. Methods and Results-Seventeen patients with recurrent VVS and 17 pair-matched control subjects underwent 70°h ead-up tilt for up to 30 minutes. Bilateral middle cerebral artery blood flow velocities (CBFV) were measured with transcranial Doppler ultrasound along with noninvasive beat-to-beat blood pressure (BP), heart rate, and transcutaneous and end-tidal CO 2 concentrations. Indices of dynamic CA were derived for periods before, during, and after tilt. Eight normal subjects who developed VVS in an identical protocol but who had no previous clinical history of syncope were also studied. CBFV and transcutaneous and end-tidal CO 2 levels declined significantly during head-up tilt in all groups (PϽ0.0001). Dynamic CA indices were unchanged throughout tilt in nonsyncopal control subjects and were initially unchanged in patients but deteriorated significantly in patients and syncopal control subjects in the minutes before (Pϭ0.027 and Pϭ0.012, respectively) and after (Pϭ0.002 and Pϭ0.007, respectively) syncope. Conclusions-Dynamic CA is preserved in patients and control subjects initially after head-up tilt. Autoregulatory function remains intact in nonsyncopal control subjects during prolonged orthostasis but deteriorates in patients and syncopal control subjects immediately before and after VVS.

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Section: Discussionmentioning

confidence: 97%

Cerebral Autoregulatory Responses to Head-Up Tilt in Normal Subjects and Patients With Recurrent Vasovagal Syncope

Carey

Manktelow²,

Panerai³

et al. 2001

Circulation

113

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“…3) We measured AP wave changes during HUT by noninvasive photoplethysmography. Nevertheless, the photoplethysmographic pressure waveform correlated very well with invasive intra-arterial pressure during tilt (21). 4) Because the baroreflex transfer functions of total, neural, and peripheral arcs have not been determined in humans, we used the characteristics of transfer function derived from animal studies (rabbits) (10,12) in numerical simulations of AP, MSNA, and their oscillations.…”

Section: Discussionmentioning

confidence: 99%

Low-frequency oscillation of sympathetic nerve activity decreases during development of tilt-induced syncope preceding sympathetic withdrawal and bradycardia

Kamiya¹,

Hayano²,

Kawada³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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. Low-frequency oscillation of sympathetic nerve activity decreases during development of tiltinduced syncope preceding sympathetic withdrawal and bradycardia. Am J Physiol Heart Circ Physiol 289: H1758 -H1769, 2005. First published June 2, 2005; doi:10.1152/ajpheart.01027.2004.-Sympathetic activation during orthostatic stress is accompanied by a marked increase in low-frequency (LF, ϳ0.1-Hz) oscillation of sympathetic nerve activity (SNA) when arterial pressure (AP) is well maintained. However, LF oscillation of SNA during development of orthostatic neurally mediated syncope remains unknown. Ten healthy subjects who developed head-up tilt (HUT)-induced syncope and 10 agematched nonsyncopal controls were studied. Nonstationary timedependent changes in calf muscle SNA (MSNA, microneurography), R-R interval, and AP (finger photoplethysmography) variability during a 15-min 60°HUT test were assessed using complex demodulation. In both groups, HUT during the first 5 min increased heart rate, magnitude of MSNA, LF and respiratory high-frequency (HF) amplitudes of MSNA variability, and LF and HF amplitudes of AP variability but decreased HF amplitude of R-R interval variability (index of cardiac vagal nerve activity). In the nonsyncopal group, these changes were sustained throughout HUT. In the syncopal group, systolic AP decreased from 100 to 60 s before onset of syncope; LF amplitude of MSNA variability decreased, whereas magnitude of MSNA and LF amplitude of AP variability remained elevated. From 60 s before onset of syncope, MSNA and heart rate decreased, index of cardiac vagal nerve activity increased, and AP further decreased to the level at syncope. LF oscillation of MSNA variability decreased during development of orthostatic neurally mediated syncope, preceding sympathetic withdrawal, bradycardia, and severe hypotension, to the level at syncope. autonomic nervous system; baroreflex; blood pressure; heart rate variability; hemodynamics HUMANS HAVE BEEN SUBJECTED to ceaseless orthostatic stresses since they first evolved and assume an orthostatic posture for most of their lives. During standing, gravitational fluid shift toward the lower part of body (i.e., abdominal vascular bed and lower limbs) would cause severe orthostatic hypotension if it were not countered by compensatory mechanisms (23). Orthostatic sympathetic activation has a crucial role in preventing orthostatic hypotension and maintaining arterial blood pressure (AP) (23). Recent studies have reported that orthostatic sympathetic activation is accompanied by an increase in lowfrequency (LF, ϳ0.1-Hz) oscillation of sympathetic nerve activity (SNA) (1, 5). Tilt maneuvers of 75°and 80°greatly increase the LF oscillatory patterns of muscle SNA (MSNA), which mirrored similar changes in LF oscillation of AP (1, 5). However, LF oscillation of SNA has been investigated only in the steady-state orthostatic condition, when AP remains well maintained. It remains unclear whether LF oscillation of SNA changes during development of orthostatic neurally mediated s...

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“…Although arterial pressure waveforms change with head-up tilt, noninvasive plethysmography correlates very well with intra-arterial pressure recordings during head-up tilt. 21 These methods have previously been used when assessing dynamic CA during head-up tilt and have been found to be reliable and consistent 8 . A direct measurement of MCA pressure is impossible without very invasive procedures that, in themselves, would affect the interpretation of our work.…”

Section: Discussionmentioning

confidence: 99%

Effect of Aging on Dynamic Cerebral Autoregulation During Head-Up Tilt

Carey

Panerai

Potter

2003

Stroke

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Background and Purpose-Physiological aging is associated with many changes in the cardiovascular and cerebrovascular systems, but dynamic cerebral autoregulation (CA) during supine rest shows no age-related changes. Because syncopal syndromes usually occur during orthostatic stress and their prevalence increases with age, it is important to define the effect of aging on dynamic CA during orthostatic stress. Methods-Twenty-five younger subjects (Յ40 years) and 25 sex-matched older subjects (Ն60 years) underwent 70°h ead-up tilt for 30 minutes. Bilateral middle cerebral artery blood flow velocities were measured with transcranial Doppler ultrasound, along with noninvasive continuous measurements of arterial blood pressure, heart rate, and transcutaneous and end-tidal carbon dioxide concentrations. By comparing actual changes in cerebral blood flow velocity to changes predicted by a model based on arterial blood pressure changes, we derived dynamic autoregulatory indexes for each subject for periods before, during, and after tilt. Results-Younger subjects were a mean of 40 years younger than older subjects (28Ϯ8 versus 69Ϯ10 years). Although cerebral blood flow velocity (PϽ0.001) and baroreceptor sensitivity (PϽ0.001) were significantly lower at rest in older subjects, autoregulatory indexes were similar in younger and older subjects at all times before, during, and after tilt (Pϭ0.62). Conclusions-Although increasing age is associated with lower cardiac baroreceptor sensitivity and cerebral blood flow velocity, dynamic CA during orthostatic stress is unaffected by physiological aging.

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A comparison of non-invasive continuous finger blood pressure measurement (Finapres) with intra-arterial pressure during prolonged head-up tilt

Cited by 86 publications

References 0 publications

Cerebral Autoregulatory Responses to Head-Up Tilt in Normal Subjects and Patients With Recurrent Vasovagal Syncope

Cerebral Autoregulatory Responses to Head-Up Tilt in Normal Subjects and Patients With Recurrent Vasovagal Syncope

Low-frequency oscillation of sympathetic nerve activity decreases during development of tilt-induced syncope preceding sympathetic withdrawal and bradycardia

Effect of Aging on Dynamic Cerebral Autoregulation During Head-Up Tilt

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