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Decreased orthostatic adrenergic reactivity in non-dipping postural tachycardia syndrome. Auton Neurosci 2014 Oct;185:107-11

Date

07/19/2014

Pubmed ID

25033770

Pubmed Central ID

PMC4165658

DOI

10.1016/j.autneu.2014.06.003

Scopus ID

2-s2.0-84908068922 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

Whether non-dipping - the loss of the physiologic nocturnal drop in blood pressure - among patients with postural tachycardia syndrome (POTS) is secondary to autonomic neuropathy, a hyperadrenergic state, or other factors remains to be determined. In 51 patients with POTS (44 females), we retrospectively analyzed 24-hour ambulatory blood pressure recordings, laboratory indices of autonomic function, orthostatic norepinephrine response, 24-hour natriuresis and peak exercise oxygen consumption. Non-dipping (<10% day-night drop in systolic blood pressure) was found in 55% (n=28). Dippers and non-dippers did not differ in: 1) baseline characteristics including demographic and clinical profile, sleep duration, daytime blood pressure, 24-hour natriuresis, and peak exercise oxygen consumption; 2) severity of laboratory autonomic deficits (sudomotor, cardiovagal and adrenergic); 3) frequency of autonomic neuropathy (7/23 vs. 8/28, P=0.885); 4) supine resting heart rate (75.3±14.0bpm vs. 74.0±13.8bpm, P=0.532); or 5) supine plasma norepinephrine level (250.0±94.9pg/ml vs. 207.0±86.8pg/ml, P=0.08). However, dippers differed significantly from non-dippers in that they had significantly greater orthostatic heart rate increment (43±16bpm vs. 35±10bpm, P=0.007) and significantly greater orthostatic plasma norepinephrine increase (293±136.6pg/ml vs. 209±91.1pg/ml, P=0.028). Our data indicate that in patients with POTS, a non-dipping blood pressure profile is associated with a reduced orthostatic sympathetic reactivity not accounted for by autonomic neuropathy.

Author List

Figueroa JJ, Bott-Kitslaar DM, Mercado JA, Basford JR, Sandroni P, Shen WK, Sletten DM, Gehrking TL, Gehrking JA, Low PA, Singer W

Author

Juan Jose Figueroa MD Assistant Professor in the Neurology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Adult
Blood Pressure
Blood Pressure Monitoring, Ambulatory
Circadian Rhythm
Female
Heart Rate
Humans
Male
Norepinephrine
Postural Orthostatic Tachycardia Syndrome
Posture
Retrospective Studies