Accordingly, Dr. Norcliffe-Kaufmann and her colleagues conducted a study of consecutive adult patients referred for autonomic evaluation at sites of the U.S. Autonomic Consortium.
The analysis was based on 402 patients with orthostatic hypotension who had normal sinus rhythm at the time of evaluation. Of that group, 378 had neurogenic orthostatic hypotension and were diagnosed with Parkinson disease, dementia with Lewy bodies, pure autonomic failure, or multiple system atrophy.
Patients with neurogenic orthostatic hypotension had twice the fall in SBP versus those with nonneurogenic causes (–43 vs. –21 mm Hg; P less than .0001), yet only about a third of the HR increase (8 vs. 25 bpm; P less than .0001), researchers reported.
They found the cHR/cSBP ratio of 0.492 bpm/mm Hg had the best sensitivity (91.3%) and specificity (88.4%) to distinguish between patients with neurogenic and nonneurogenic orthostatic hypertension.