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Cerebral critical closing pressure and resistance-area product: the influence of dynamic cerebral autoregulation, age, and sex.

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journal contribution
posted on 04.05.2021, 09:36 by Ronney B Panerai, Victoria J Haunton, Osian Llwyd, Jatinder S Minhas, Emmanuel Katsogridakis, Angela Sm Salinet, Paola Maggio, Thompson G Robinson
Instantaneous arterial pressure-flow (or velocity) relationships indicate the existence of a cerebral critical closing pressure (CrCP), with the slope of the relationship expressed by the resistance-area product (RAP). In 194 healthy subjects (20-82 years, 90 female), cerebral blood flow velocity (CBFV, transcranial Doppler), arterial blood pressure (BP, Finapres) and end-tidal CO2 (EtCO2, capnography) were measured continuously for five minutes during spontaneous fluctuations of BP at rest. The dynamic cerebral autoregulation (CA) index (ARI) was extracted with transfer function analysis from the CBFV step response to the BP input and step responses were also obtained for the BP-CrCP and BP-RAP relationships. ARI was shown to decrease with age at a rate of -0.025 units/year in men (p = 0.022), but not in women (p = 0.40). The temporal patterns of the BP-CBFV, BP-CrCP and BP-RAP step responses were strongly influenced by the ARI (p < 0.0001), but not by sex. Age was also a significant determinant of the peak of the CBFV step response and the tail of the RAP response. Whilst the RAP step response pattern is consistent with a myogenic mechanism controlling dynamic CA, further work is needed to explore the potential association of the CrCP step response with the flow-mediated component of autoregulation.

History

Author affiliation

Department of Cardiovascular Sciences

Version

VoR (Version of Record)

Published in

Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism

Publisher

SAGE Publications

issn

0271-678X

eissn

1559-7016

Acceptance date

16/02/2021

Copyright date

2021

Available date

04/05/2021

Spatial coverage

United States

Language

eng