The Pathophysiology of Orthostatic Hypotension

May 7, 2021 updated by: Emily M. Garland, Vanderbilt University Medical Center
The purpose of this study is to determine the cause of low blood pressure in selective patients who have problems with their involuntary (autonomic) nervous system. These patients frequently have had symptoms throughout their life, and their disorder might have a genetic basis. The biochemical, physiological and pharmacological procedures in this study should help us define the problem and perhaps lead to more effective treatment.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

10

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Tennessee
      • Nashville, Tennessee, United States, 37232
        • Vanderbilt University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

12 years to 70 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • severe orthostatic hypotension and other autonomic symptoms but do not meet criteria for standard diagnosis
  • non-smokers
  • drug-free
  • able to give informed consent
  • free of pulmonary, renal, hematopoietic, hepatic and cardiac disease

Exclusion Criteria:

  • medications affecting the autonomic nervous system
  • any chronic illness
  • anemia (Hct<30)
  • women of childbearing age who are pregnant or nursing
  • smokers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: A
Patients with Orthostatic Hypotension
Procedure: Standing or upright tilt
stand upright or tilt table test
Procedure: Microneurography
Recording from sympathetic nerve
Procedure: QSweat
quantitative sweat testing
Device: neck cuff stimulation
Blood pressure receptors in the neck arteries may be stimulated by applying suction through a collar around the neck.
Drug: phenylephrine,isoproterenol,nitroprusside,propranolol,edrophonium,atropine,tyramine

IV Pharmacological Testing

phenylephrine 12.5 - 400 ug, isoproterenol 0.1 - 0.4 ug or higher until desired effect, nitroprusside 0.1 - 1.6 ug/kg, propranolol 1.1 mg/min, edrophonium maximum of 10 mg, atropine .01 mg/kg, tyramine 250-4000 ug or higher until desired effect

Drug: clonidine,yohimbine,metoclopramide,alpha-methyldopa

Oral Pharmacological Testing

clonidine 0.1-0.3 mg, yohimbine 5-10 mg, metoclopramide 10 mg, alpha-methyldopa 62.5 mg, placebo

Procedure: BodPod
Determination of body composition
Procedure: Eye exam

Examination of pressure in the eye and eyelid fatiguability. The following eyedrops might be used:

  1. 0.5% proparacaine (Alcaine, Allergan, Inc)
  2. Fluress (0.4% benoxinate hydrochloride, fluorescein sodium, Akorn, Inc)
  3. 0.5%, 1% tropicamide (Mydriacyl, Alcon)
  4. Over-the-counter preservative-free artificial tears
  5. 0.25%, 2.5% and 10% phenylephrine (Bausch and Lomb)
  6. 1% cyclopentolate hydrochloride (Alcon)
Procedure: Sleep study
Recording of sleep pattern overnight
Procedure: Pain response testing
Subjects will rate the quality and intensity of 2 pain tasks.
Procedure: Metabolic chamber
Determination of metabolic rate via 24hr stay in whole-room indirect calorimeter
Procedure: Brain function studies
Questionnaires and computer tasks, an EEG and an MRI may be used to assess brain function.
Procedure: Bicycle Exercise Test
Blood pressure and heart rate may be monitored while exercising on a stationary bicycle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
hemodynamic changes with standing
Time Frame: following test
following test

Secondary Outcome Measures

Outcome Measure
Time Frame
blood and urine hormones
Time Frame: after test
after test
blood volume
Time Frame: during supine and/or upright postures
during supine and/or upright postures
sympathetic nerve activity
Time Frame: during stimulation of sympathetic nervous system
during stimulation of sympathetic nervous system
quantitative sweat testing
Time Frame: 2 hours
2 hours
Eye function
Time Frame: once
once
Sleep efficiency
Time Frame: once
once
Metabolic rate
Time Frame: once
once
Pain response
Time Frame: once
once
Responses on questionnaires and computer tasks designed to assess brain function
Time Frame: once
once

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vanderbilt University Medical Center

Investigators

  • Principal Investigator: Emily M Garland, PhD, Vanderbilt University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 1996

Primary Completion (Actual)

December 1, 2020

Study Completion (Actual)

December 1, 2020

Study Registration Dates

First Submitted

September 5, 2008

First Submitted That Met QC Criteria

September 5, 2008

First Posted (Estimate)

September 8, 2008

Study Record Updates

Last Update Posted (Actual)

May 12, 2021

Last Update Submitted That Met QC Criteria

May 7, 2021

Last Verified

May 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 030752
  • HL056693

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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