Carotid duplex ultrasonography during head-up tilt in patients with orthostatic hypotension.

Orthostatic hypotension (OH) is defined by evaluating postural blood pressure (BP) change, but the correlation between postural BP decreases and OH-associated symptoms is poor. We examined carotid duplex ultrasonography during HUT in 27 patients with various neurological disorders. Nine patients were diagnosed to have OH, and 4 of them had symptoms associated with OH. Decreased end-diastolic velocity of common carotid artery in symptomatic OH patients (-24.5 +/- 4.2 cm/s) was significantly larger than that in asymptomatic OH patients (-11.0 +/- 8.0 cm/s; p = 0.0143), despite no significant differences in values and changes of BP between them. This may be useful for predicting the development of OH symptoms.