Search results for "Orthostatic"

Measuring postural-related changes of spontaneous baroreflex sensitivity after repeated long-duration diving: Frequency domain approaches

2012

Sustained water immersion is thought to modulate orthostatic tolerance to an extent dependent on the duration and repetition over consecutive days of the diving sessions. We tested this hypothesis investigating in ten healthy subjects the potential changes in the cardiovascular response to head-up tilt induced by single and multiple resting air dives. Parametric cross-spectral analysis of spontaneous RR interval and systolic arterial pressure variability was performed in three experimental sessions: before diving (BD), after single 6-hour dive (ASD), and after multiple 6-hour dives (AMD, 5 consecutive days with 18-hour surface interval). From this analysis, baroreflex sensitivity (BRS) was …

Conditional Self-Entropy and Conditional Joint Transfer Entropy in Heart Period Variability during Graded Postural Challenge.

2015

Self-entropy (SE) and transfer entropy (TE) are widely utilized in biomedical signal processing to assess the information stored into a system and transferred from a source to a destination respectively. The study proposes a more specific definition of the SE, namely the conditional SE (CSE), and a more flexible definition of the TE based on joint TE (JTE), namely the conditional JTE (CJTE), for the analysis of information dynamics in multivariate time series. In a protocol evoking a gradual sympathetic activation and vagal withdrawal proportional to the magnitude of the orthostatic stimulus, such as the graded head-up tilt, we extracted the beat-to-beat spontaneous variability of heart per…

Balance control in aging: improvements in anticipatory postural adjustments and updating of internal models

2015

International audience; Postural stability of older subjects can be estimated during orthostatic equilibrium. However, dynamic equilibrium is also important to investigate risks of fall. It implies different interpretations of measures given by force plates. Same dependant variables (e.g. center of pressure displacement) cannot be interpreted the same ways depending of the type of equilibrium that is investigated. In particular, sways increases during dynamic equilibrium and before movement execution may reflect an improvement of feedforward control.

Ability of short-time Fourier transform method to detect transient changes in vagal effects on hearts: a pharmacological blocking study.

2006

Conventional spectral analyses of heart rate variability (HRV) have been limited to stationary signals and have not allowed the obtainment of information during transient autonomic cardiac responses. In the present study, we evaluated the ability of the short-time Fourier transform (STFT) method to detect transient changes in vagal effects on the heart. We derived high-frequency power (HFP, 0.20–0.40 Hz) as a function of time during active orthostatic task (AOT) from the sitting to standing posture before and after selective vagal (atropine sulfate 0.04 mg/kg) and sympathetic (metoprolol 0.20 mg/kg) blockades. The HFP minimum point during the first 30 s after standing up was calculated and…

PSYCHOBEHAVIORAL DISORDERS, ORTHOSTATIC HYPOTENSION, AND FALLS RELATED TO A PHEOCHROMOCYTOMA IN A VERY ELDERLY SUBJECT: A CASE REPORT

2010

Hipertensión arterial episódica asociada al síndrome de taquicardia postural ortostática

2006

Se presenta el caso clínico de una mujer de 17 años de edad que acude en reiteradas ocasiones a urgencias por palpitaciones, taquicardia, síncope, reacción vegetativa de escasa duración, con recuperación espontánea y completa y detección de cifras elevadas de presión arterial. Estudiada en diversas consultas de especialidades y tras múltiples exploraciones complementarias no se encontró patología que justificase el cuadro. Ante la sospecha de intolerancia ortostática o síndrome de taquicardia postural ortostática con hipertensión se realizó la prueba de estimulación con cama basculante a 60°, confirmándose el diagnóstico y comprobando la desaparición de los síntomas al iniciar tratamiento c…

Cardiovascular autonomic function and MCI in Parkinson's disease

2019

Abstract Introduction dysautonomic dysfunction and cognitive impairment represent the most disabling non-motor features of Parkinson's Disease (PD). Recent evidences suggest the association between Orthostatic Hypotension (OH) and PD-Dementia. However, little is known on the interactions between cardiovascular dysautonomia and Mild Cognitive Impairment (MCI). We aimed to evaluate the association between cardiovascular dysautonomia and MCI in patients with PD. Methods non-demented PD patients belonging to the PACOS cohort underwent a comprehensive instrumental neurovegetative assessment including the study of both parasympathetic and sympathetic function (30:15 ratio, Expiratory-Inspiratory …

Efficacy and tolerability of lercanidipine in monotherapy in elderly patients with isolated systolic hypertension

2000

To investigate the efficacy and tolerability of lercanidipine, used as monotherapy once a day, in elderly patients with isolated systolic hypertension (ISH), 83 patients were enrolled in this multicenter, double-blind, randomized, placebo-controlled study. All patients were older than 60 years, and their mean age was 66.7 +/- 5.4 years. ISH was defined as SBPor = 160 mmHg, and DBP95 mmHg. After wash-out and placebo run-in periods, patients were randomly assigned to placebo or lercanidipine (10 mg once a day) treatment for 4 weeks. Non-responding patients of the lercanidipine-treated group were later treated with 20 mg of lercanidipine once a day for 4 additional weeks. At the end of the stu…

Serum 25-Hydroxyvitamin D and Orthostatic Hypotension in Old People

2014

Interest in the association between serum 25-hydroxyvitamin D (25OHD) and blood pressure has increased because recent research showed a close relationship between them, but there is still little information on the possible association between 25OHD and orthostatic hypotension. The aim of this study was to explore the relationship of 25OHD levels with any presence of orthostatic hypotension in a large group of older people. This study was part of the Progetto Veneto Anziani (Pro.V.A.), an Italian population–based cohort study involving people aged >65 years. In this cross-sectional work, we considered 2640 (1081 men and 1559 women) with a mean age of 73.8±6.8 years. Orthostatic hypotensi…

Cardiovascular and ocular safety of α1-adrenoceptor antagonists in the treatment of male lower urinary tract symptoms

2014

α1-Adrenoceptor antagonists (α-blockers) represent first-line drug treatment for male lower urinary tract symptoms. Their adverse events (AEs) include asthenia, dizziness, nasal congestion, arterial (orthostatic) hypotension and intraoperative floppy iris syndrome (IFIS).This report focuses on cardiovascular and ocular AEs of α-blockers as related to their mechanism of action and subtype selectivity.The incidence of hypotension differs between α-blockers. It is greatest with doxazosin or terazosin, but others including tamsulosin can also lead to hypotension especially upon treatment initiation. Concomitant antihypertensive medication increases the incidence of hypotension with some α-block…