Aldosterone & Sodium Regulation in Postural Tachycardia Syndrome - Screening

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.

Conditions

• Postural Tachycardia Syndrome

Interventions

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.

PROCEDURE

Measurement of Total Blood Volume

Total blood volume is measured by using iodinated I-131 tagged human serum albumin.

OTHER

Exercise Capacity Test

Participants will ride on a stationary recumbent bicycle and the resistance will be gradually increased while expired air is measured.

Sponsors & Collaborators

• National Institutes of Health (NIH)

  collaborator NIH

• National Heart, Lung, and Blood Institute (NHLBI)

  collaborator NIH

• Vanderbilt University

  lead OTHER

Principal Investigators

• Alfredo J Gamboa, MD · Vanderbilt University Medical Center

Study Design

Allocation

NA

Purpose

SCREENING

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

50 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-02-28

Primary Completion

2026-12-31

Completion

2026-12-31

Countries

• United States

Study Locations