Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/17552
Title: Spontaneous fluctuations in cerebral blood flow regulation: contribution of PaCO2.
Authors: Panerai, RB
Dineen, NE
Brodie, FG
Robinson, TG
First Published: Dec-2010
Citation: J APPL PHYSIOL, 2010, 109 (6), pp. 1860-1868
Abstract: To investigate the temporal variability of dynamic cerebral autoregulation (CA), the transient response of cerebral blood flow to rapid changes in arterial blood pressure, a new approach was introduced to improve the temporal resolution of dynamic CA assessment. Continuous bilateral recordings of cerebral blood flow velocity (transcranial Doppler, middle cerebral artery), end-tidal Pco(2) (Pet(CO(2)), infrared capnograph), and blood pressure (Finapres) were obtained at rest and during breath hold in 30 young subjects (25 ± 6 yr old) and 30 older subjects (64 ± 4 yr old). Time-varying estimates of the autoregulation index [ARI(t)] were obtained with an autoregressive-moving average model with coefficients expanded by orthogonal decomposition. The temporal pattern of ARI(t) varied inversely with Pet(CO(2)), decreasing with hypercapnia. At rest, ARI(t) showed spontaneous fluctuations that were significantly different from noise and significantly correlated with spontaneous fluctuations in Pet(CO(2)) in the majority of recordings (young: 72% and old: 65%). No significant differences were found in ARI(t) due to aging. This new approach to improve the temporal resolution of dynamic CA parameters allows the identification of physiologically meaningful fluctuations in dynamic CA efficiency at rest and in response to changes in arterial CO(2).
DOI Link: 10.1152/japplphysiol.00857.2010
eISSN: 1522-1601
Links: http://hdl.handle.net/2381/17552
Type: Journal Article
Appears in Collections:Published Articles, Dept. of Cardiovascular Sciences

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