Tilt Table With Suspected Postural Orthostatic Tachycardia Syndrome (POTS) Subjects
Dysautonomia, primarily defined as postural orthostatic tachycardia syndrome (POTS) can seriously disrupt a child's daily activities. It is most commonly associated with nausea or abdominal pain. In preliminary studies, when orthostatic intolerance was treated with fludrocortisone, a standard therapy for orthostatic intolerance (OI), symptomatic improvement in nausea was observed. However, children with POTS were also observed to have higher supine mean arterial pressure (MAP) (preliminary data) and greater suppression of the baroreceptor reflex sensitivity (BRS) occurred upon up-right tilt. While fludrocortisone alleviates nausea associated with OI, its long-term use may pose long term health risks to children including worsening hypertension. Therefore, it is the objective of this study to define the mechanism for OI as it relates to nausea. The investigators hypothesize that OI resulting from changes in the autonomic nervous system is the likely mechanism for the nausea observed in the patients in this study. The investigators further hypothesize that this is potentially an early marker for future cardiovascular problems such as early onset hypertension and cardiac hypertrophy. The general objective of this protocol is to address this gap in knowledge by determining the autonomic characteristics of children with OI as well as defining neurohumoral profiles for these subjects to better understand the cause of the elevated supine in these subjects. By better understanding the potential mechanism for this condition, it is the investigators future goal to develop a more focused and safer treatment strategy. The investigators will study subjects between 10 to 18 years of age utilizing the tilt table to mimic daily life stressors and also measure serum levels of epinephrine, norepinephrine, rennin, angiotensin II, aldosterone, and vasopressin at baseline and during tilt. This study will generate data with high impact in that more rational treatments for management of dysautonomia could be chosen on the basis of the profile of dysautonomia and neurohumoral markers.
Postural Orthostatic Tachycardia Syndrome
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Tilt Table and Autonomic Testing in Suspected POTS Subjects|
- Autonomic Testing in Suspected POTS Subjects [ Time Frame: Change in autonomic system 15 minute post baseline ] [ Designated as safety issue: No ]We will address the hypothesis that elevated supine MAP accompanies the CV dysautonomia in children presenting with symptoms of POTS.
- Change in Heart Rate and Blood Pressure in Suspected POTS Subjects [ Time Frame: Change in Heart rate and blood pressure 15 minutes after baseline ] [ Designated as safety issue: No ]We will identify neurohumoral characteristics for each group to establish the underlying mechanisms for the elevated supine MAP and the dysautonomia in these subjects leading to a more focused approach to treatment.
|Study Start Date:||March 2012|
|Estimated Study Completion Date:||March 2014|
|Estimated Primary Completion Date:||December 2013 (Final data collection date for primary outcome measure)|
Normal tilt test
Patients with normal tilt table testing (they may have symptoms which precipitated the tilt, but in the end did not qualify as POTS, NMH, ETC.)
confirmed POTS diagnosis
after review of tilt table results, this group will be the confirmed postural orthostatic tachycardic syndrome group patient
Neurocardiogenic syncope on tilt
This group is comprised of patients with confirmed diagnosis of neurocardiogenic syncope on tilt
Patients with confirmed diagnosis neurally mediated hypotension
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|United States, North Carolina|
|Wake Forest University Baptist Health Center|
|Winston Salem, North Carolina, United States, 27157|
|Principal Investigator:||John E Fortunato, MD||Wake Forest University Baptist Health Center|