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(Stroke. 2000;31:1672.)
© 2000 American Heart Association, Inc.
Original Contributions |
From the Neurovascular Research Laboratory (J.M.S., P.A.P., J.K.S., R.L.B.), School of Kinesiology, and the Robarts Research Institute (B.K.R.), The University of Western Ontario, London, Ontario, Canada.
Correspondence to Dr Kevin Shoemaker, Neurovascular Research Laboratory, School of Kinesiology, The University of Western Ontario, London, Ontario, Canada N6A 3K7. E-mail kshoemak{at}julian.uwo.ca
Background and PurposeThe relationship between middle cerebral artery (MCA) flow velocity (CFV) and cerebral blood flow (CBF) is uncertain because of unknown vessel diameter response to physiological stimuli. The purpose of this study was to directly examine the effect of a simulated orthostatic stress (lower body negative pressure [LBNP]) as well as increased or decreased end-tidal carbon dioxide partial pressure (PETCO2) on MCA diameter and CFV.
MethodsTwelve subjects participated in a CO2
manipulation protocol and/or an LBNP protocol. In the CO2
manipulation protocol, subjects breathed room air (normocapnia) or 6%
inspired CO2 (hypercapnia), or they hyperventilated to
25 mm Hg PETCO2
(hypocapnia). In the LBNP protocol, subjects experienced 10
minutes each of -20 and -40 mm Hg lower body suction. CFV and
diameter of the MCA were measured by transcranial
Doppler and MRI, respectively, during the experimental
protocols.
ResultsCompared with normocapnia, hypercapnia produced increases in both PETCO2 (from 36±3 to 40±4 mm Hg, P<0.05) and CFV (from 63±4 to 80±6 cm/s, P<0.001) but did not change MCA diameters (from 2.9±0.3 to 2.8±0.3 mm). Hypocapnia produced decreases in both PETCO2 (24±2 mm Hg, P<0.005) and CFV (43±7 cm/s, P<0.001) compared with normocapnia, with no change in MCA diameters (from 2.9±0.3 to 2.9±0.4 mm). During -40 mm Hg LBNP, PETCO2 was not changed, but CFV (55±4 cm/s) was reduced from baseline (58±4 cm/s, P<0.05), with no change in MCA diameter.
ConclusionsUnder the conditions of this study, changes in MCA diameter were not detected. Therefore, we conclude that relative changes in CFV were representative of changes in CBF during the physiological stimuli of moderate LBNP or changes in PETCO2.
Key Words: cerebral blood flow hypotension, orthostatic middle cerebral artery ultrasonography, Doppler, transcranial
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||||
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||||
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