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Aldosterone & Sodium Regulation in Postural Tachycardia Syndrome - Screening

This study is ongoing, but not recruiting participants.
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Emily M. Garland, Vanderbilt University Identifier:
First received: January 25, 2013
Last updated: April 3, 2017
Last verified: March 2017
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.

Condition Intervention
Postural Tachycardia Syndrome
Other: Autonomic Function Testing
Other: Posture Study
Procedure: Measurement of Total Blood Volume
Other: Exercise Capacity Test

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: No masking
Primary Purpose: Screening
Official Title: Aldosterone and Sodium Regulation in Postural Tachycardia Syndrome - Screening Protocol

Resource links provided by NLM:

Further study details as provided by Vanderbilt University Medical Center:

Primary Outcome Measures:
  • blood volume deviation (%) from individual predicted volumes [ Time Frame: 2 days ]
    Compare blood volume deviations using the 131-I-Albumin method. Deviations will be reported as a percentage deviation from an individual's predicted value. These values will be compared between POTS patients and healthy control groups.

Estimated Enrollment: 110
Study Start Date: February 2013
Estimated Study Completion Date: February 2018
Estimated Primary Completion Date: February 2018 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
All participants

All participants will be administered all procedures as described previously.


Autonomic Function Testing, Posture Study ,Measurement of Total Blood Volume ,Exercise Capacity Test

Other: Autonomic Function Testing

heart 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.

Other: Posture Study
Blood pressure, heart rate and blood samples (for catecholamines and hormones) will be measured & collected in the supine (lying) and upright position for each participant.
Other Name: Supine & standing blood pressure, heart rate & blood draws.
Procedure: Measurement of Total Blood Volume
Total blood volume is measured by using iodinated I-131 tagged human serum albumin.
Other Names:
  • blood sample at baseline and at 12 minutes
  • I-131 is administered.
Other: Exercise Capacity Test
Participants will ride on a stationary recumbent bicycle and the resistance will be gradually increased while expired air is measured.
Other Name: Masimal Oxygen Consumption Test

  Show Detailed Description


Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01783288

United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Emily Garland, PhD, MSCI Vanderbilt University Medical Center
  More Information

Responsible Party: Emily M. Garland, Research Associate Professor, Vanderbilt University Identifier: NCT01783288     History of Changes
Other Study ID Numbers: IRB 121817
R01HL102387 ( US NIH Grant/Contract Award Number )
Study First Received: January 25, 2013
Last Updated: April 3, 2017

Keywords provided by Vanderbilt University Medical Center:
Postural tachycardia syndrome
orthostatic intolerance
orthostatic tachycardia

Additional relevant MeSH terms:
Postural Orthostatic Tachycardia Syndrome
Pathologic Processes
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases processed this record on April 24, 2017