Please use this identifier to cite or link to this item:
|Title:||The cerebro-cardiovascular response to periodic squat-stand maneuvers in healthy subjects: a time-domain analysis.|
|Authors:||Barnes, Sam C.|
Haunton, Victoria Joanna
Robinson, Thompson G.
Panerai, Ronney B.
|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.|
|Embargo on file until:||8-Sep-2018|
|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|
Files in This Item:
|Subcomponent R1 clean AJP_HCP2017.pdf||Post-review (final submitted author manuscript)||568.92 kB||Adobe PDF||View/Open|
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.