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Aldosterone & Sodium Regulation in Postural Tachycardia Syndrome - Screening

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01783288
Recruitment Status : Active, not recruiting
First Posted : February 4, 2013
Last Update Posted : January 10, 2019
National Institutes of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Emily M. Garland, Vanderbilt University

Brief Summary:
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 or disease Intervention/treatment Phase
Postural Tachycardia Syndrome Other: Autonomic Function Testing Other: Posture Study Procedure: Measurement of Total Blood Volume Other: Exercise Capacity Test Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 110 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Screening
Official Title: Aldosterone and Sodium Regulation in Postural Tachycardia Syndrome - Screening Protocol
Study Start Date : February 2013
Estimated Primary Completion Date : December 2019
Estimated Study Completion Date : December 2019

Resource links provided by the National Library of Medicine

Drug Information available for: Aldosterone

Arm Intervention/treatment
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

Primary Outcome Measures :
  1. 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.

Information from the National Library of Medicine

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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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01783288

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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)
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Principal Investigator: Emily Garland, PhD, MSCI Vanderbilt University Medical Center

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Responsible Party: Emily M. Garland, Research Associate Professor, Vanderbilt University Identifier: NCT01783288     History of Changes
Other Study ID Numbers: IRB 121817
R01HL102387 ( U.S. NIH Grant/Contract )
First Posted: February 4, 2013    Key Record Dates
Last Update Posted: January 10, 2019
Last Verified: January 2019

Keywords provided by Emily M. Garland, Vanderbilt University:
Postural tachycardia syndrome
orthostatic intolerance
orthostatic tachycardia

Additional relevant MeSH terms:
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Postural Orthostatic Tachycardia Syndrome
Pathologic Processes
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Cardiac Conduction System Disease
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases