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Title: The cerebro-cardiovascular response to periodic squat-stand maneuvers in healthy subjects: a time-domain analysis.
Authors: Barnes, Sam C.
Ball, Naomi
Haunton, Victoria Joanna
Robinson, Thompson G.
Panerai, Ronney B.
First Published: 8-Sep-2017
Publisher: American Physiological Society
Citation: AJP - Heart and Circulatory Physiology, 2017, ajpheart.00331.2017
Abstract: BACKGROUND: Squat-stand maneuvers (SSMs) have been used to improve the coherence of transfer function analysis (TFA) estimates during the assessment of dynamic cerebral autoregulation (dCA). There is a need to understand the influence of peripheral changes resulting from SSMs on cerebral blood flow, which might confound estimates of dCA. METHODS: 29 healthy subjects underwent recordings at rest (5 min standing) and 15 SSMs (0.05Hz). Heart rate (3-lead ECG), end-tidal CO2 (capnography), blood pressure (Finometer), cerebral blood velocity (CBV, transcranial Doppler, MCA) and the angle of the thigh (tilt sensor) were measured continuously. The response of CBV to SSMs was decomposed into the relative contributions of mean arterial pressure (MAP), resistance area product (RAP) and critical closing pressure (CrCP). RESULTS: Upon squatting, a rise in MAP (83.6 ± 21.1 % contribution) is followed by increased CBV. A dCA response can be detected, determined by adjustments in RAP and CrCP (left hemisphere) with peak contributions of 24.8 ± 12.7 % and 27.4 ± 22.8 %, respectively, at different times during SSMs. No interhemispheric differences were detected. During standing, the contributions of MAP, RAP and CrCP change considerably. CONCLUSIONS: The changes of CBV subcomponents during repeated SSMs indicate a complex response of CBVms. to SSMs that can only be partially explained by myogenic mechanis More work is needed to clarify the potential contribution of other co-factors, such as breath-to-breath changes in pCO2, HR, stroke volume and the neurogenic component of dynamic CA.
DOI Link: 10.1152/ajpheart.00331.2017
ISSN: 0363-6135
eISSN: 1522-1539
Embargo on file until: 8-Sep-2018
Version: Post-print
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2017, American Physiological Society. Deposited with reference to the publisher’s open access archiving policy.
Description: The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.
Appears in Collections:Published Articles, Dept. of Cardiovascular Sciences

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