We recorded the change of blood flow velocity before, during and after hyperventilation (HV) in bilateral Internal Carotid Arteries (ICA) and Vertebral Arteries (VA) simultaneously and continuously of 4 healthy males.
The MULTI-DOPPLER-SYSTEM (HAYASHI ELECTRIC, Inc. Kawasaki, JAPAN) and four ultrasonic probes fixed by a cervical brace (KAWAMURA ARTIFICIAL LIMB, Inc.Osaka, JAPAN) were used to obtain data.
We calculated Averaged Maximum Velocity (AMV) for every heart beat as the Index of blood flow and visualized them in 4 subjects.
AMV repeatedly increased and decreased every several seconds. HV induced a statistically significant AMY decrease. The AMY interrelations between any two vessels in each subject were all statistically significant. The coefficients of correlation were largest during HV and smallest before HV.
