Introduction:
The study was to assess the differences of cerebrovascular reactivity in healthy subjects during orthostasis.
Subjects and methods:
Twenty healthy volunteers (11 men and 9 women) with no atherosclerotic risk factors were evaluated by means of transcranial Doppler. A breath holding index (BHI) was obtained in supine and standing position using standardized procedure. Student's t-test was used for intergroup comparison of mean blood flow velocities (MBFV) and BHI values between supine and standing position and for left to right assessment.
Results:
Mean blood flow velocity (MBFV) in a middle cerebral artery in supine position was 66.6 cm/s on the right side and 68.5 cm/s on the left side, and in standing position 60.6 cm/s on the right side, 62.3 cm/s on the left side. There was no significant difference in values of MBFV comparing supine and standing position and also between males and females. Mean BHI in supine position was 1.59 on the right side, 1.65 on the left side, and in standing position 1.63 on the right side, 1.7 on the left side, without significant difference comparing males and females. There was no statistically significant differences in the BHI between supine and standing position (P = 0.81 for the right side, P = 0.68 for the left side) neither between sides in supine (P= 0.71) and standing position (P= 0.8).
Conclusion:
There was no significant difference in BHI values during orthostatic stress in evaluation ofcerebrovascular reactivity.
