Iron Sucrose in Adolescents With Iron Deficiency and Postural Orthostatic Tachycardia Syndrome (POTS)...
Postural Orthostatic Tachycardia SyndromeThis study is designed to investigate whether the treatment of non-anemic iron deficiency with intervenous iron sucrose will result in decreased symptom reporting and improved cardiovascular indices in adolescents (age 12-21) with Postural Orthostatic Tachycardia Syndrome (POTS).
Hemodynamic Response of Neuropathic And Non-Neuropathic POTS Patients To Adrenoreceptor Agonist...
Postural Orthostatic Tachycardia SyndromeOrthostatic IntoleranceThe purpose of this study is to test the hypothesis that patients with non-neuropathic POTS will have different responsiveness than patients with neuropathic POTS to direct alpha-1 adrenoreceptor agonist therapy (droxidopa) and to non-selective beta-adrenoreceptor antagonist therapy (atenolol). The specific goal of this protocol is to investigate the effect of atenolol and droxidopa on cardiovascular autonomic functions such as cardiovagal control, sympathetic nerve activity, and sympathetic vascular transduction, systemic hemodynamic response to orthostatic stress and on the quality of life in neuropathic and non-neuropathic patients with postural tachycardia syndrome (POTS). Standardized tests are used to assess cardiovagal control function, sympathetic nerve activity, sympathetic vascular transduction, systemic hemodynamic response to head-up tilt test and standardized questionnaires to assess the quality of life in patients with POTS. The cardiovagal, sympathetic and hemodynamic measurements are performed after and during drug administration. To control the effect of medications placebo is used on separate testing visits. The order of drugs and placebo is randomized.
Assessment of Antibodies and Inflammatory Markers in Postural Tachycardia Syndrome
Postural Orthostatic Tachycardia SyndromeIn this pilot study, the investigators will test the hypothesis that patients with postural tachycardia syndrome will have an elevated percentage of functional antibodies to adrenergic receptors compared with control subjects without POTS. The investigators further hypothesize that the percentage of POTS patients with antibodies will be higher in those patients with a viral infection at the onset of their illness than in those patients with other or undefined illness onsets.
Hemodynamic Effects of Compression in POTS
Postural Tachycardia SyndromeWhen an individual with Postural Tachycardia Syndrome (POTS) stands up, their heart rate increases significantly (>30BPM) and they may experience symptoms such as lightheadedness, dizziness, shortness of breath, nausea and mental confusion. One commonly prescribed treatment for POTS is compression garments. Compression garments squeeze veins to help return blood back to the heart, which may decrease heart rate and symptoms on standing. However, there is little research about the effectiveness of compression in adults with POTS. In this study, the investigators will use the Lifewrap garment, which compresses the abdomen, pelvis and lower extremities, to evaluate the effectiveness of compression in POTS. The investigators will use a head up tilt (HUT) which will simulate standing. The study participant will participate in 4x 10 minute HUTs wearing 4 different compression configurations: full abdomen and lower extremity compression abdominal only compression leg only compression No compression The investigators hypothesize that with full compression, the participant's heart rate increase from lying down to upright will be lower than when they are not wearing any compression. The investigators will also ask the participant about their symptoms when they are upright. The results of this study could demonstrate the potential benefits of compression and what configuration is most effective. These findings could rapidly translate to the clinical setting, providing improved care.
The Impact of Improved Vagal Function on Periaqueductal Gray Connectivity
Postural Tachycardia SyndromeThis study is being to see if participating in breathing exercise training and practicing this training will help with Postural tachycardia syndrome (POTS). The information may help doctors to learn more about how the different parts of people's brains communicate.
Alterations of Attention in POTS Depending on Body Position and Hydration
Postural Tachycardia SyndromeThe Postural Tachycardia-Syndrome (POTS) is a form of autonomic dysregulation, typically accompanied by symptoms of orthostatic intolerance (OI). OI is defined by the inability to tolerate the upright position and is improved by lying down. POTS is considered a syndrome that may include a number of several disorders. Symptoms should be persistent for at least 6 months to reach a diagnosis. It is characterized by a sustained heart rate (HR) increment of 30 beats/min or more within 10 min of standing or head-up tilt (HUT) in adults, in the absence of orthostatic hypotension and with the presence of symptoms of OI. In children and adolescents a diagnosis requests a HR increment of at least 40 beats/min. The increment in HR when moving to an upright posture is often a response to a reduction in venous return, causing excessive blood pooling in the lower limbs. The symptoms present in POTS vary greatly. Typical symptoms are lightheadedness, dizziness, blurred vision, mental clouding ("brain fog") or cognitive dysfunction. Other symptoms may present as palpitations or chest pain. Additional symptoms consist of postural headaches, nausea, sleep disturbances, fatigue and gastrointestinal dysfunction. The manifestation of symptoms in POTS varies in severity, frequency and combination, resulting in POTS being a very heterogenous and subjective disorder. Symptoms can be severe and often make simple daily activities difficult to an extent that compromises the patients quality of life. Typically symptoms exacerbate in the mornings, after physical activity, after eating and during menstruation. This study objective is to examine the occurrence, mechanisms and causes of impaired attention in POTS as well as to test the effect of acute water ingestion for attention in POTS. The investigators therefore conduct a study including patients with POTS and healthy volunteers. All participants will receive a dossier of five self-assessment questionnaires after giving informed consent. Clinical examination includes 2 HUT-tests while standing for 15 minutes, conventional measuring of blood pressure, continuous recording of NIRS signals during testing, determination of pupil size, the diameter of the optic nerve and Neuropsychological testing (Test of Attentional Performance, mobility version" (TAP-M), Go/NoGo Test, Divided Attention Test)
The Exercise Response to Pharmacologic Cholinergic Stimulation in Myalgic Encephalomyelitis / Chronic...
Myalgic Encephalomyelitis/Chronic Fatigue SyndromeChronic Fatigue Syndrome7 moreMyalgic 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.
Gabapentin Treatment of Postural Tachycardia Syndrome (PoTS)
Postural Orthostatic Tachycardia SyndromeIn this pilot study, the investigator will test the usefulness of gabapentin in treating some of the symptoms associated with POTS. Gabapentin is FDA-approved to treat epilepsy and nerve pain and works by reducing excessive activity in the nervous system. This medication has also been shown to be effective in reducing bowel discomfort in patients with irritable bowel syndrome, sleeplessness, and possibly migraine headache. The investigator has observed positive results when prescribing gabapentin off-label to alleviate photosensitivity and headaches in POTS patients. The aim of this pilot study is to better quantify what the investigator has seen and evaluate whether it merits further study in a larger group.
Abdominal and Lower Extremity Compression During Tilt Table Testing in Adolescent POTS Patients...
Postural Orthostatic Tachycardia Syndrome (POTS)SyncopePostural orthostatic tachycardia syndrome (POTS) is a common cause of orthostatic intolerance in adolescents and adults. Compression stockings are commonly recommended as a treatment modality for POTS, but the effects of abdominal and lower extremity compression during tilt table testing have not been measured in adolescent patients. The aims of our study are to compare heart-rate changes and symptom onset during tilt table testing (a) with and without abdomen/lower extremity compression and (b) with abdominal compression only versus lower extremity compression only. During phase 1, 20 adolescents with POTS will undergo up to 10 minutes of tilt without compression (trial #1), a repeat study of up to 10 minutes with full compression (trial #2), and a third study without compression up to 10 minutes (trial #3). Compression will be performed using the non-inflatable Zoex anti-shock garment. During study phase 2, an additional 20 adolescent POTS patients will undergo up to 10 minutes of tilt without compression (trial #1), a repeat study of up to 10 minutes with abdominal compression only [n=10] or lower extremity compression only [n=10] (trial #2), and a third study repeated without compression up to 10 minutes (trial #3). To limit compression to the abdomen only, we will use the Zoex garment strap numbers 4 and 5 (thigh and abdomen) without straps 1-3 (lower extremities). For lower extremity-only compression, we will use Zoex garment straps 1-4 (lower extremity and thigh) without strap 5. Data collected will include mean and peak heart rates and timing of symptoms with each trial. A paired-samples t-test will be used to compare mean heart rates between trials for each study phase. Hazard analyses will be used to assess time-based endpoints.
Effect of Ivabradine on Patients With Postural Orthostatic Tachycardia Syndrome
Postural Orthostatic Tachycardia SyndromePostural orthostatic tachycardia syndrome (POTS) occurs in approximately 500,000 Americans, but predominates in women with a 5:1 ratio. Patients with POTS experience debilitating tachycardia upon postural changes such as standing that impairs their quality of life. Tachycardia is clinically defined as a heart rate greater than 100 beats/min; and in POTS patients, the prolonged heart rate increase is greater than 30 beats/min or increases to 120 beats/min within the first ten minutes of a diagnostic tilt table test without postural hypotension. There are currently no effective treatment methods for POTS. However, several studies suggest Ivabradine could be a main treatment option for POTS because Ivabradine specifically inhibits the f-channels (If) within the sinoatrial (SA) node, which slows the heart rate. Currently in the US, Ivabradine is mainly prescribed to treat chronic heart failure. It is well tolerated in patients, but it is not commonly prescribed for POTS. It has been also used for treatment of inappropriate sinus tachycardia with good benefit. The hypothesis for this experiment is that Ivabradine will reduce tachycardia and improve functional status in patients with POTS.