Acute Salt Handling in Orthostatic Intolerance

This study is ongoing, but not recruiting participants.
National Institutes of Health (NIH)
Information provided by (Responsible Party):
Satish R. Raj, Vanderbilt University Identifier:
First received: December 22, 2007
Last updated: December 18, 2014
Last verified: December 2014
The investigators will test the hypothesis that patients with chronic orthostatic intolerance or postural orthostatic tachycardia syndrome (OI or POTS) will be unable to conserve urinary sodium as compared to healthy control subjects.

Condition Intervention
Postural Tachycardia Syndrome
Orthostatic Tachycardia
Orthostatic Intolerance
Other: normal saline (0.9%)

Study Type: Interventional
Study Design: Endpoint Classification: Pharmacokinetics Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Acute Renal Salt Handling in Orthostatic Intolerance

Resource links provided by NLM:

Further study details as provided by Vanderbilt University:

Primary Outcome Measures:
  • Urinary Na excretion [ Time Frame: 24h and then hourly post saline load ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Catecholamine levels [ Time Frame: 1 day ] [ Designated as safety issue: No ]

Estimated Enrollment: 30
Study Start Date: February 2007
Estimated Study Completion Date: December 2016
Estimated Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
saline infusion for sodium loading
Other: normal saline (0.9%)
liter normal saline over 30 minutes x 1 dose

Detailed Description:
Patients with chronic OI appear to be hypovolemic with abnormalities in hormones that regulate salt & water handling. Increases in dietary salt have salutary effects on orthostatic tolerance in a physiological laboratory. The infusion of intravenous saline acutely decreased heart rate in this patient population. Preliminary data from Vanderbilt suggests abnormal salt handling in patients with chronic OI in a few patients. These data need to be confirmed and a better understanding of sodium handling in response to acute salt loads is required in these patients.

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Diagnosed with orthostatic intolerance by Vanderbilt Autonomic Dysfunction Center (or healthy control subject)

Exclusion Criteria:

  • Overt or acute cause for orthostatic tachycardia
  • Hypertension (BP>145/95 or need for anti-hypertensive medications)
  • QRS duration > 120 msec on EKG
  • Pregnancy
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Please refer to this study by its identifier: NCT00581633

United States, Tennessee
Vanderbilt University
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
National Institutes of Health (NIH)
Principal Investigator: Satish R Raj, MD MSCI Vanderbilt University
  More Information

Additional Information:
No publications provided

Responsible Party: Satish R. Raj, Assistant Professor of Medicine & Pharmacology, Vanderbilt University Identifier: NCT00581633     History of Changes
Other Study ID Numbers: 061230, NIH 1 UL1 RR024975, NIH K23 RR020783, NIH P01 HL 56693
Study First Received: December 22, 2007
Last Updated: December 18, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Vanderbilt University:

Additional relevant MeSH terms:
Mitral Valve Prolapse
Neurocirculatory Asthenia
Orthostatic Intolerance
Postural Orthostatic Tachycardia Syndrome
Anxiety Disorders
Arrhythmias, Cardiac
Autonomic Nervous System Diseases
Cardiovascular Diseases
Heart Diseases
Heart Valve Diseases
Heart Valve Prolapse
Mental Disorders
Nervous System Diseases
Neurologic Manifestations
Pathologic Processes
Primary Dysautonomias
Signs and Symptoms processed this record on November 30, 2015