Postural Tachycardia Syndrome |
Postural Tachycardia Syndrome research study
What is the primary objective of this study?
The purpose of the study is to determine whether patients meet criteria for Postural Tachycardia Syndrome (or not) and have reduced blood volume (or not). Both of these are important screening elements to Aim 3 of a National Institutes of Health Grant. The purposes of Aim 3 are to determine 1. whether a high dietary sodium level appropriately expands plasma volume in Postural Orthostatic Tachycardia, 2. whether plasma renin activity and aldosterone are modified appropriately by changes in dietary sodium in Postural Tachycardia Syndrome and 3. whether patients with Postural Tachycardia Syndrome have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.
Who is eligible to participate?
Inclusion Criteria: - Age between 18-50 years old - Patients with suspected POTS and healthy volunteers - Sedentary healthy subjects of similar age and gender than patients will also be recruited. - Only female participants are eligible. - Able and willing to provide informed consent Exclusion Criteria: - Smokers - Overt cause for postural tachycardia, i.e., acute dehydration - Significant cardiovascular, pulmonary, hepatic, or hematological disease by history or prior testing - Highly trained athletes - Subjects with somatization or severe anxiety symptoms will be excluded - Pregnant (positive pregnancy test) or breastfeeding - Hypertension defined as supine resting BP>145/95 mmHg off medications or needing antihypertensive medication - Other factors which in the investigator's opinion would prevent the participant from completing the protocol, including poor compliance during previous studies or an unpredictable schedule - Unable to give informed consent
Which medical condition, disease, disorder, syndrome, illness, or injury is researched?
Postural Tachycardia Syndrome
Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.
Other:Autonomic Function Testingheart rate and blood pressure will be continuously monitored while participants undergo a variety of breathing techniques (deep breathing, rapid breathing, blowing against resistance) and during sustained handgrip and cold pressor (hand in ice water). All tests are meant to stimulate the autonomic nervous system to produce changes in blood pressure and heart rate of short duration that reflect how well the autonomic nervous system is functioning. Also during autonomic function testing, cardiac output will be measured to analyze the shift of fluids in the body (body impedance) and / or by analyzing the air that is breathed.
Procedure:Measurement of Total Blood VolumeTotal blood volume is measured by using iodinated I-131 tagged human serum albumin.
Other:Exercise Capacity TestParticipants will ride on a stationary recumbent bicycle and the resistance will be gradually increased while expired air is measured.
Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.
All participantsAll participants will be administered all procedures as described previously. Interventions: Autonomic Function Testing, Posture Study ,Measurement of Total Blood Volume ,Exercise Capacity Test
Active, not recruiting
Start Date: February 2013
Completed Date: February 2018
Primary Outcome: blood volume deviation (%) from individual predicted volumes
Study sponsors, principal investigator, and references
Principal Investigator: Emily Garland, PhD, MSCI
Lead Sponsor: Vanderbilt University
Collaborator: National Institutes of Health (NIH)