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Acute Salt Handling in Orthostatic Intolerance

Not Applicable
Active, not recruiting
Conditions
Orthostatic Intolerance
Postural Tachycardia Syndrome
Orthostatic Tachycardia
Interventions
Other: normal saline (0.9%)
Registration Number
NCT00581633
Lead Sponsor
Vanderbilt University
Brief Summary

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.

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.

Recruitment & Eligibility

Status
ACTIVE_NOT_RECRUITING
Sex
All
Target Recruitment
30
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
1normal saline (0.9%)saline infusion for sodium loading
Primary Outcome Measures
NameTimeMethod
Urinary Na excretion24h and then hourly post saline load
Secondary Outcome Measures
NameTimeMethod
Catecholamine levels1 day

Trial Locations

Locations (1)

Vanderbilt University

🇺🇸

Nashville, Tennessee, United States

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