title: Transcranial Doppler-determined change in posterior cerebral artery blood flow velocity does not reflect vertebral artery blood flow during exercise.
abstract: We examined whether a change in posterior cerebral artery flow velocity (PCAv) reflected the posterior cerebral blood flow in healthy subjects during both static and dynamic exercise. PCAv and vertebral artery (VA) blood flow, as an index of posterior cerebral blood flow, were continuously measured during an exercise trial using transcranial Doppler (TCD) ultrasonography and Doppler ultrasound, respectively. Static handgrip exercise significantly increased both PCAv and VA blood flow. Increasing intensity of dynamic exercise further increased VA blood flow from moderate exercise, while PCAv decreased to almost resting level. During both static and dynamic exercise, the PCA cerebrovascular conductance (CVC) index significantly decreased from rest (static and high-intensity dynamic exercise, -11.5 ± 12.2% and -18.0 ± 16.8%, means ± SD, respectively) despite no change in the CVC of VA. These results indicate that vasoconstriction occurred at PCA but not VA during exercise-induced hypertension. This discrepancy in vascular response to exercise between PCA and VA may be due to different cerebral arterial characteristics. Therefore, to determine the effect of exercise on posterior cerebral circulation, at least, we need to carefully consider which cerebral artery to measure, regardless of exercise mode.NEW & NOTEWORTHYWe examined whether transcranial Doppler-determined flow velocity in the posterior cerebral artery can be used as an index of cerebral blood flow during exercise. However, the changes in posterior cerebral artery flow velocity during exercise do not reflect vertebral artery blood flow.
authors.affiliation: Department of Biomedical Engineering, Toyo University, Kawagoe-shi, Japan.
authors.forename: Takuro
authors.initials: T
authors.lastname: Washio
authors.affiliation: Department of Biomedical Engineering, Toyo University, Kawagoe-shi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Department of Biomedical Engineering, Toyo University, Kawagoe-shi, Japan ogoh@toyo.jp.
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Ogoh
mesh_terms: D001642:Bicycling / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D010100:Oxygen / Q000097:blood; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D012146:Rest / Q000502:physiology; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D014661:Vasoconstriction / Q000502:physiology; D014711:Vertebral Artery / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Doppler ultrasound; cerebral blood flow velocity; posterior cerebral circulation; transcranial Doppler ultrasonography; vertebral artery