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Acute Salt Handling in Orthostatic Intolerance

This study is ongoing, but not recruiting participants.
National Center for Research Resources (NCRR)
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Satish R. Raj, Vanderbilt University Identifier:
First received: December 22, 2007
Last updated: March 22, 2017
Last verified: March 2017
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: Intervention Model: Single Group Assignment
Masking: No masking
Primary Purpose: Diagnostic
Official Title: Acute Renal Salt Handling in Orthostatic Intolerance

Resource links provided by NLM:

Further study details as provided by Satish R. Raj, Vanderbilt University:

Primary Outcome Measures:
  • Urinary Na excretion [ Time Frame: 24h and then hourly post saline load ]

Secondary Outcome Measures:
  • Catecholamine levels [ Time Frame: 1 day ]

Estimated Enrollment: 30
Study Start Date: February 2007
Estimated Study Completion Date: December 2018
Estimated Primary Completion Date: December 2018 (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   (Adult)
Sexes Eligible for Study:   All
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
  Contacts and Locations
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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 Center for Research Resources (NCRR)
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Satish R Raj, MD MSCI Vanderbilt University
  More Information

Additional Information:
Responsible Party: Satish R. Raj, Assistant Professor of Medicine & Pharmacology, Vanderbilt University Identifier: NCT00581633     History of Changes
Other Study ID Numbers: 061230
UL1RR024975 ( US NIH Grant/Contract Award Number )
K23RR020783 ( US NIH Grant/Contract Award Number )
P01HL056693 ( US NIH Grant/Contract Award Number )
Study First Received: December 22, 2007
Last Updated: March 22, 2017

Keywords provided by Satish R. Raj, Vanderbilt University:

Additional relevant MeSH terms:
Postural Orthostatic Tachycardia Syndrome
Orthostatic Intolerance
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases
Neurologic Manifestations
Signs and Symptoms processed this record on June 23, 2017