Equal contribution of first two authors.
Vasomotor reactivity as a predictor for syncope in patients with orthostatism
Version of Record online: 14 SEP 2011
© 2011 John Wiley & Sons A/S
Acta Neurologica Scandinavica
Volume 126, Issue 1, pages 32–36, July 2012
How to Cite
Gur, A. Y., Auriel, E., Korczyn, A. D., Gadoth, A., Shopin, L., Giladi, N., Bornstein, N. M. and Gurevich, T. (2012), Vasomotor reactivity as a predictor for syncope in patients with orthostatism. Acta Neurologica Scandinavica, 126: 32–36. doi: 10.1111/j.1600-0404.2011.01591.x
- Issue online: 6 JUN 2012
- Version of Record online: 14 SEP 2011
- Accepted for publication August 16, 2011.
- cerebrovascular reactivity;
- cerebral autoregulation;
- Doppler ultrasonography;
- orthostatic hypotension;
Gur AY, Auriel E, Korczyn AD, Gadoth A, Shopin L, Giladi N, Bornstein NM, Gurevich T. Vasomotor reactivity as a predictor for syncope in patients with orthostatism. Acta Neurol Scand: 2012: 126: 32–36. © 2011 John Wiley & Sons A/S.
Objectives – Syncope in patients with orthostatic hypotension (OH) may be the result of impaired cerebral autoregulation. Cerebral autoregulation status can be determined by assessing cerebral vasomotor reactivity (VMR). We assessed and compared VMR in patients with OH with and without syncope.
Material and methods – Twenty-nine patients with OH underwent transcranial Doppler (TCD) and the Diamox test (1 g acetazolamide IV) for assessing VMR during elaboration of their OH syndrome. The percent difference between cerebral blood flow velocities (BFV) in the middle cerebral (MCA) and vertebral (VA) arteries before and after acetazolamide was defined as VMR%. We considered increases of BFV of ≥40% as being indicative of good VMR and classified our study patients as having good or impaired VMRs accordingly.
Results – Mean VMR% values of the MCA and VA in patients with OH with syncope (n = 12) were significantly lower as compared with patients with OH without syncope (n = 17): 25.2 ± 20.5% and 42.5 ± 18.6%; 20.9 ± 15.5% and 40.8 ± 28.5%, respectively (P < 0.05).
Conclusions – Among patients with OH, we found an association between the presence of syncope and impaired VMR. Assessment of VMR among patients with OH may predict those who are at higher risk to faint and fall and to support more aggressive intervention.