Decreased orthostatic adrenergic reactivity in non-dipping postural tachycardia syndrome.
Auton Neurosci
; 185: 107-11, 2014 Oct.
Article
en En
| MEDLINE
| ID: mdl-25033770
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.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Presión Sanguínea
/
Ritmo Circadiano
/
Síndrome de Taquicardia Postural Ortostática
Tipo de estudio:
Observational_studies
/
Risk_factors_studies
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Auton Neurosci
Asunto de la revista:
NEUROLOGIA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos