View clinical trials related to Orthostatic Hypotension.
Filter by:Myalgic encephalomyelitis/Chronic fatigue syndrome (ME/CFS), otherwise known as Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME), is an under-recognized disorder whose cause is not yet understood. Suggested theories behind the pathophysiology of this condition include autoimmune causes, an inciting viral illness, and a dysfunctional autonomic nervous system caused by a small fiber polyneuropathy. Symptoms include fatigue, cognitive impairments, gastrointestinal changes, exertional dyspnea, and post-exertional malaise. The latter two symptoms are caused in part by abnormal cardiopulmonary hemodynamics during exercise thought to be due to a small fiber polyneuropathy. This manifests as low biventricular filling pressures throughout exercise seen in patients undergoing an invasive cardiopulmonary exercise test (iCPET) along with small nerve fiber atrophy seen on skin biopsy. After diagnosis, patients are often treated with pyridostigmine (off-label use of this medication) to enhance cholinergic stimulation of norepinephrine release at the post-ganglionic synapse. This is thought to improve venoconstriction at the site of exercising muscles, leading to improved return of blood to the heart and increasing filling of the heart to more appropriate levels during peak exercise. Retrospective studies have shown that noninvasive measurements of exercise capacity, such as oxygen uptake, end-tidal carbon dioxide, and ventilatory efficiency, improve after treatment with pyridostigmine. To date, there are no studies that assess invasive hemodynamics after pyridostigmine administration. It is estimated that four million people suffer from ME/CFS worldwide, a number that is thought to be a gross underestimate of disease prevalence. However, despite its potential for debilitating symptoms, loss of productivity, and worldwide burden, the pathophysiology behind ME/CFS remains unknown and its treatment unclear. By evaluating the exercise response to cholinergic stimulation, this study will shed further light on the link between the autonomic nervous system and cardiopulmonary hemodynamics, potentially leading to new therapeutic targets.
The pilot study aims to evaluate a prototype system that enables military pilots to train under conditions of orthostatic hypotension and ischemic hypoxia. Both of these phenomena are experienced by aircraft crews of mainly highly maneuverable aircraft, and their syndromes include loss of color vision, loss of peripheral vision, blackout and finally G-induced loss of consciousness (G-LOC). A motorized tilt table to generate orthostatic (ORTHO) stress combined with an automatically controlled lower body negative pressure (LBNP) chamber to extort pooling of blood in the lower extremities has been developed in order to obtain new knowledge on counteracting the above-mentioned effects and minimizing the risk of their occurrence. This will help optimize the selection procedures of candidates with the best physiological predispositions to work as military pilots. The system is equipped with modules for monitoring biomedical parameters of a subject, including cerebral oxygenation, which ensures their safety and provides a source of data for performing advanced analyses. The ORTHO-LBNP system has been subjected to comprehensive laboratory tests and after a successful testing is ready for a pilot study involving pilots and/or cadets of the Polish Air Force Academy (PAFA). It is anticipated that new indicators will be proposed to enable an objective assessment of the predispositions to pursue a military pilot career. The prototype system can be easily adaptable to the needs of clinical and sports medicine as well as rehabilitation.
While treatment strategies for OH have been identified for use in persons with acute SCI, the field of SCI medicine lacks a gold standard for treatment thresholds and well-defined outcome parameters. Comprehensively documenting the impact of orthostatic hypotension (OH), regardless of symptoms, during acute rehabilitation and identifying the effects of two different treatment approaches on therapy participation and adherence to an intended rehabilitation plan could have a significant impact on clinical practice in the acute rehabilitation setting following SCI.
Suspension syndrome refers to a potentially life-threatening condition that can occur in unconscious persons after prolonged suspension in a harness. To date, our understanding of the pathophysiology and appropriate treatment is based primarily on case reports and expert opinion. The main pathophysiological hypothesis implicates blood pooling in the lower extremity and lack of return via muscle pumping. However, a recent French study could not support this hypothesis. Other mechanisms, such as a central vagal reflex may play a role in the pathophysiology of suspension syndrome. The aim of this study is to better understand the pathophysiological basis of suspension syndrome and to develop practical recommendations for prevention and treatment.
This multiple-center, 3-part, single-blind dose escalation (Part A), randomized, double-blind (Part B), and open-label multiple dose extension (Part C) study will be conducted in male and female subjects with neurogenic orthostatic hypotension to evaluate the effect of TD-9855 in improving symptoms of orthostatic intolerance.
One of the most physiologically demanding things that older people do every day is to get up in the morning. After spending a night laying flat, where the blood distributes evenly across the body, when they stand in the morning (and the blood rushes to their feet), their cardiovascular system may not be able to compensate and maintain blood flow to the brain. This phenomenon is known as orthostatic or postural hypotension. The investigators have found in a group of young individuals that use of a dawn-simulation light that gradually wakes the brain is able to increase cardiovascular tone prior to arising. The goal of this experiment is to determine whether this dawn simulation light is able to increase cardiovascular tone in older adults such that they would have reduced or absent postural hypotension when they awaken in the morning. This would greatly reduce the risks of falls and their associated morbidities in older adults.
Postural hypotension is common in older people, leading to falls, decline in function, and dependence. Available treatments have limited efficacy and tolerability; novel approaches to treatment are therefore needed. Decreased vascular health, stiffening of the arteries and consequent decreased vascular reactivity are thought to contribute to postural hypotension and are therefore therapeutic targets. Recent trial evidence has suggested that vitamin K may exert beneficial effects on vascular health particularly in respect to inhibiting calcification. Calcification increases vascular stiffness, decreases compliance and thus decreases the ability of blood vessels to autoregulate blood pressure and flow - which could contribute to postural drops in blood pressure. Worsened vascular health could also impact adversely on baroceptor function, which is needed for blood pressure autoregulation and which is disrupted in patients with orthostatic hypotension. Vitamin K intake is below recommended daily intake in 60% of adults in the UK. In animals, vitamin K supplementation may be able to reverse calcification of arteries, and in humans Vitamin K has been shown to arrest decline in carotid artery elasticity compared to placebo. High levels of circulating vitamin K were also associated with lower levels of CRP in the Framingham cohort, suggesting a possible role in the suppression of chronic inflammation that is known to accompany vascular disease. The recent ECKO study suggested that vitamin K may reduce falls and fractures; an intriguing question that follows on from this is whether this could be due to beneficial effects on vascular health and postural hypotension, leading to less dizziness and reduced falls. This cross-sectional comparative study aims to find whether there is a difference in the vitamin K status of patients with postural hypotension compared to those without postural hypotension and whether differences in vitamin K status are associated with other markers of vascular function in patients with and without postural hypotension. This could potentially lead to new treatments for the condition for which there is currently little of proven benefit.
Background: The presence of orthostatic hypotension (OH) as a consequence of blood volume redistribution during verticalisation in persons with spinal cord injury (SCI) is a common condition. Aims: To investigate the impact of three different types of electric stimulation (ES) (ES of the abdominal muscles versus ES of lower limb muscles versus simultaneously ES of abdominal and lower limb muscles versus control) on blood pressure stabilization and verticalisation-degrees between 0° and 70°. The hypothesis is, that the ES-induced contractions of the muscles cause a stabilisation respectively an increase of the blood pressure during the tilt-table test. Subjects: 20 Women and men, at least 18 years of age, following an acute and traumatic SCI, with a lesion level above T6, an American Spinal Injury Association (AIS) Impairment Scale A,B or C and a diagnosis of OH (by tilt table test) were eligible for the study. Methods: Each patient underwent randomly three different types of ES sessions while being positioned on a tilt-table. The following sessions were planned: A) ES of the abdominal muscles B) ES of the lower limb muscles C) Combination of A and B D) Control session (=diagnostic session) Study type: Intervention Design: Prospective interventional study
Individuals with acute cervical spinal cord injury (SCI) can suffer from an excessive and prolonged fall in blood pressure when assuming an upright position, such as transitioning from lying to sitting or standing, a condition also known as orthostatic hypotension (OH). Due to a decrease in cerebral oxygenation, affected individuals can develop debilitating symptoms including lightheadedness, blurred vision, fatigue and even loss of consciousness. Recent evidence suggests that OH has a negative impact on cognition in individuals with SCI. Clinical observations suggest that OH can lead to neurological deterioration in individuals who may otherwise have a stable SCI. The presence of symptomatic OH prevented participation in 43% of physical therapy treatment sessions in a study of individuals with acute SCI despite the use of current treatment options. OH is known to adversely affect health, delay rehabilitation and prolong hospitalization in the acute phase of management of individuals who display it. Our team found OH was present in 41 of 55 (75%) patients with acute cervical SCI at our center in 2004. We plan to research the efficacy of a low-cost, non-invasive device known as transcranial electrical stimulation (TES) to manage OH in individuals with acute cervical SCI. Previous studies have shown that this device is safe to use in individuals with SCI, and has improved blood pressure control in non-SCI individuals. We hypothesize that in individuals with acute cervical SCI and OH, TES intervention will elicit an attenuation of the drop in systolic BP (SBP)in response to orthostatic stress. TES-induced differences will be most pronounced in those individuals with sparing of spinal autonomic pathways
An International, multicenter, epidemiological observational study investigating the prevalence of Transthyretin-Related Familial Amyloidotic Polyneuropathy (TTR-FAP) in participants with small fiber polyneuropathy of no obvious etiology.