View clinical trials related to Orthostatic Intolerance.
Filter by:The purpose of Lunar OI (Orthostatic Intolerance) is to determine if there are differences between males and females in tolerance to and cardiovascular responses during different angles of head-up tilt simulating gravity levels less than or equal to Earth's gravity. Also, this study will determine if a gradient compression garment affects tolerance to tilting and the cardiovascular stress at different tilt angles. Males and females are being identified by biological sex. This will be a two-phased study design. In Phase I we will determine whether there are differences in the development of signs or symptoms of orthostatic intolerance between males and females when tilted head up on a table to different angles to simulate gravity levels that astronauts may experience when landing on or launching from the surface of the Moon. In Phase II, the tilt tests simulating the same gravity levels from Phase I will be repeated, but a custom-made lower-body compression garment will be worn to see if wearing the garment affects the development of orthostatic intolerance. For both study phases, before tilting, a drug will be administered to reduce the amount fluid in the blood (plasma) to levels similar to that experienced by astronauts during spaceflight.
Observational two phase, retrospective and prospective registry study to assess the prevalence of and characterize outcomes of autonomic dysfunction (AD) in patients who undergo bariatric surgery (BS) and to better define the underlying pathophysiology of AD following BS.
Background Orthostatic hypotension (OH) is a common cause of falls, and key source of morbidity and mortality due to injury (e.g. hip fracture). Current guidelines recommend increasing salt intake in patients with symptomatic orthostatic hypotension. However, the evidence underpinning this recommendation is poor, based primarily on small trials with very short-term follow-up (< 6 weeks). Clinical Equipoise (Overall) High salt intake might improve quality of life and reduce the risk of falls, but might also increase the risk of cardiovascular disease, in patients with OH. Specific Objective of Current Application (Aim) To determine feasibility (recruitment, retention and adherence) of conducting a randomized controlled trial evaluating high salt intake in older adults with symptomatic orthostatic hypotension. To determine preliminary estimates of the effect of high salt intake on disease-specific quality of life, orthostatic blood pressure (BP) parameters, and cardiac blood biomarkers. Design: Phase IIa, parallel, double-blind, randomised controlled, single centre clinical trial of 12 month follow-up duration. Population: Older adults (≥65 years of age) with an objective diagnosis of symptomatic orthostatic hypotension Intervention: The intervention will be 5g/day of salt supplementation in the form of encapsulated sodium chloride. Outcome measures: Primary outcome (Feasibility) recruitment and retention rates, adherence with intervention and study protocol, completeness of follow-up. Secondary Outcome (Efficacy): i) clinical: change in Orthostatic Hypotension Questionnaire score, modification/addition of OH pharmacotherapy, and falls events, ii) physiological measures of orthostasis: change in difference between supine and nadir systolic BP, standing BP at 1 minute, 24 hour mean BP measured by 24 hour ambulatory BP monitor, iii) cardiovascular biomarkers. Clinical Importance: A recommendation for long-term increases in salt intake may have adverse cardiovascular consequences, which necessitates the identification of the optimal range of salt intake associated with greatest reduction in falls risk and lowest cardiovascular risk. Our study will provide preliminary evidence of treatment effect and assess feasibility, to inform a definitive trial.
This is a pilot dose-finding study to test the hypothesis that mirabegron increases systolic blood pressure (BP), prevents syncope/presyncope, and improves the quality of life (QOL), functional capacity, chest pain, and overactive bladder (OAB) symptoms in patients with postural orthostatic tachycardia syndrome (POTS) who have a documented history of hypotension inadequately responsive to conventional treatments. The American Heart Association funds this study.
Pilot-case-control study on exertion and orthostatic intolerance of adolescents with myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS) compared to age-matched healthy controls (HC).
The goal of this clinical trial (pilot study) is to learn about the microcirculatory regulation of the lower extremity under orthostatic stress with and without RIC - Remote Ischemic Preconditioning in healthy participants. The main question it aims to answer are: Do the beneficial effects of RIC withstand orthostatic stress? / Does RIC benefit lower extremity microcirculation in ortho-statically stressed subjects? Is there a relationship/correlation between the variables of microcirculation and hemodynamics in the context of RIC and orthostatic loading?
Background: The investigational device, "Task Force® CORE" (TFC, CNSystems Medizintechnik GmbH, Graz, Austria) together with the "Task Force® CARDIO" (TFCARDIO, CNSystems Medizintechnik GmbH, Graz, Austria) medical device software, is a new CE-marked medical device for continuous non-invasive determination of blood pressure (BP), cardiac output (CO) and derived parameters based on the well established CNAP® (continuous non-invasive arterial pressure) technology by CNSystems. Aim: The primary aim of this prospective, method comparison, open study is data acquisition for the performance evaluation of the TFC during autonomic function testing in comparison with an clinically accepted reference method. Setting: The setting of the clinical investigation will be the autonomic function testing laboratory at the Department of Neurology, the University Hospital Center Zagreb. Inclusion criteria: Patients who are over 18 years and who provide written informed consent. Sample size: The study has an calculated sample size of 70 patients. Considering a drop-out rate of 5%, a total of 75 patients will be included. Statistics: Descriptive statistics, values for the percentage error and correlation estimates will be derived. Furthermore, scatterplot, Bland-Altman analysis, concordance analysis of parameter changes and further comparative statistics will be performed.
The investigators are interested in whether discrete counterpressure maneuvers, or muscle movements in the lower body, will boost blood pressure and cardiovascular control in children who faint. We will record cardiovascular responses to maneuvers of exaggerated sway, leg crossing, crouching, and gluteal muscle tensing in children who faint (N=20), as well as their height, weight, muscularity, and pubertal (Tanner) stage. Autonomic cardiovascular control will be measured using a Valsalva manoeuvre (expiration against a closed airway for 20 seconds) and a supine-stand test. The primary outcomes are noninvasive measures of cardiovascular responses to the maneuvers (blood pressure, cerebral blood flow, and stroke volume (volume of blood pumped per heartbeat). Comparisons will be made across levels of sex, diagnosis, Tanner stage, muscularity, height, and degree of autonomic control.
The investigators will assess the efficacy of clinically recommended counterpressure maneuvers (CPM) in preventing syncope for paediatric patients. Participants presenting to the emergency department (ED) will first provide written informed consent. In stage I, they will be asked to complete a brief survey documenting the presentation of their syncopal episode, and any prodromal symptoms they experienced. Participants that consent to the second stage of the study will either receive usual care (control arm) or training in counter pressure maneuvers alongside usual care (intervention arm; leg crossing, bending, arm tensing). These patients will be followed for one years time, and will be asked to complete monthly surveys detailing their syncopal and presyncopal recurrence. Medical records will be accessed over the duration of the study to identify any changes in medical diagnosis.
Rationale: Systolic hypertension represents the leading risk for burden of disease among older adults (age >70 years), with an increasing prevalence due to the increase in lifespan. Antihypertensive drug treatment (AHT) is beneficial in fit (non-frail) older adults, with substantial (≈40 %) risk reductions for cardiovascular events and mortality. Scarce evidence exists on the risks of adverse effects related to AHT. It has been suggested in medical literature that AHT in frail elderly might cause cerebral hypoperfusion and/or orthostatic hypotension. Therefore, current guidelines advise clinicians to be more cautious regarding treatment targets in this population. However, the evidence for these adverse effects is limited to observational and cross-sectional data and opinion pieces. In contrast to the suggestion of potential adverse effects of AHT in elderly, recent experimental data and secondary analyses of clinical trials do not provide support for this statement. However, evidence in frail older patients remains scarce. Studies that directly examine the safety of AHT with regard to cerebral hemodynamics and orthostatic tolerance in frail elderly are needed to inform potential changes in current treatment guidelines and prevent undertreatment of hypertension in frail older patients. Objective: To examine the impact of medication induced systolic BP (SBP) reductions ≥10 mmHg, while reaching a treatment target of ≤140 mmHg, on cerebral blood flow (CBF) in frail elderly with untreated or uncontrolled systolic hypertension at baseline. We hypothesise that these blood pressure lowering targets (which are consistent with clinical guidelines for non-frail older patients) are not accompanied by detrimental reductions in CBF (i.e. >10% from baseline). Study design: An explorative observational study will be performed to examine the effects of medication induced SBP reductions ≥10 mmHg to office SBP ≤140 mmHg on CBF in frail elderly with untreated or uncontrolled hypertension. Participants will be treated as in usual patient care for older adults with hypertension. Participants will undergo one baseline assessment before exposure to (additional) AHT, followed by in duplo follow-up assessments 6-10 weeks after the start of AHT. The in duplo follow-up evaluations will be performed on separate days within 2 weeks while continuing treatment. Study population: Twelve frail (Clinical Frailty Scale 4-7) elderly (age ≥70 years) with untreated or uncontrolled systolic hypertension (office SBP ≥150 mmHg) that will be subjected to (additional) AHT as part of regular care. Main study parameters/endpoints: The change in resting CBF from baseline to follow-up (i.e. the average of the in duplo follow-up assessments). Secondary outcomes relate to cerebrovascular autoregulation (CA) and orthostatic tolerance. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Subjects will be subjected to AHT, essentially identical to what is considered 'guideline care', while their wellbeing will be monitored closely. Since all study procedures and used measurement techniques are non-invasive, the nature and extent of burden and risks associated with participation and measurements are negligible.