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Evaluation of Chronic Orthostatic Intolerance

NCT00069693 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 200

Last updated 2017-07-02

No results posted yet for this study

Summary

This study will conduct tests with patients with primary chronic orthostatic intolerance (COI) to learn more about this disorder of the autonomic nervous system.

Healthy normal volunteers and patients 18 years of age and older with COI may be eligible for this study. Participants undergo one or more of the following tests and procedures:

* Blood studies, including arterial catheter insertion to measure blood pressure and collect arterial blood samples, blood flow studies using sensors applied to the skin and a pressure cuff around a limb, blood volume studies using injection of radioactively labeled human serum albumin and gene studies to look for genetic abnormalities associated with certain proteins.
* Imaging studies, including CT scan of the adrenal glands, heart ultrasound, and PET scanning.
* Electrocardiogram
* Microdialysis to measures levels of chemicals in the body fluid of certain tissues. A thin tube is inserted into the skin and a solution is passed through it. Chemicals in the body tissues enter the solution in the tube. The solution is collected and the chemical levels are measured.
* Neck suction. Neck suction is applied to test a reflex the brain uses to regulate blood pressure.
* Perometry. Limb volume is measured using an infrared light that moves up the limb.
* Quantitative sudomotor axon reflex test to evaluate an aspect of autonomic nervous system function. A small amount of a brain chemical (acetylcholine) is applied to the skin with a tiny amount of electricity, and the sweat in a nearby patch of skin is measured.
* Skin electrical conduction test using sensors on the skin to measure sweat production.
* Skin and core temperature measurements using sensors on the skin and in the ear canal.
* Tilt table test. The subject lies on a table, secured with straps around the chest and legs. Sensors are placed on the arms and chest to monitor blood pressure, pulse rate, and heart rhythm. A catheter is placed in a vein in each arm to collect blood samples and give drugs. Another catheter is placed in an artery to draw blood and monitor blood pressure. The subject is given an infusion of norepinephrine and epinephrine, and baseline measures and blood samples are taken. The table is tilted upright and more measurements and blood samples are taken at intervals for up to 30 minutes. The table is returned to a horizontal position and additional measurements and samples may be taken.

Drugs may be administered during the tests, including acetylcholine, epinephrine, and norepinephrine, radioactive chemicals used in imaging studies, and drugs that affect blood vessels, heart rate, and force of heart contractions.

Conditions

  • Syncope

Sponsors & Collaborators

  • National Institute of Neurological Disorders and Stroke (NINDS)

    lead NIH

Eligibility

Min Age
10 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2003-09-26
Completion
2008-08-05

Countries

  • United States
  • Canada

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00069693 on ClinicalTrials.gov