Measurement of blood pressure and heart-rate variation while resting supine and standing for the evaluation of autonomic dysfunction.

Blood pressure and R-R interval variation were studied during postural changes using a tilting table. The subjects were 64 normal controls and 52 patients with various disorders. None of the normal controls showed postural falls of more than 15 mm Hg in mean blood pressure. The mean loge coefficient of variation of 100 R-R intervals was significantly reduced in groups with Parkinson's disease, spinocerebellar degeneration, Shy-Drager syndrome and diabetes mellitus, compared with a normal control group. Reduced heart-rate variation was frequently associated with sphincter disturbance and orthostatic hypotension.