The Pathophysiology of Orthostatic Hypotension

The Pathophysiology of Orthostatic Hypotension

Sponsors

Lead Sponsor: Vanderbilt University Medical Center

Source Vanderbilt University Medical Center
Brief Summary

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.

Overall Status Active, not recruiting
Start Date December 1996
Completion Date December 2021
Primary Completion Date December 2021
Phase Phase 1
Study Type Interventional
Primary Outcome
Measure Time Frame
hemodynamic changes with standing following test
Secondary Outcome
Measure Time Frame
blood and urine hormones after test
blood volume during supine and/or upright postures
sympathetic nerve activity during stimulation of sympathetic nervous system
quantitative sweat testing 2 hours
Eye function once
Sleep efficiency once
Metabolic rate once
Pain response once
Responses on questionnaires and computer tasks designed to assess brain function once
Enrollment 25
Condition
Intervention

Intervention Type: Procedure

Intervention Name: Standing or upright tilt

Description: stand upright or tilt table test

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Microneurography

Description: Recording from sympathetic nerve

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: QSweat

Description: quantitative sweat testing

Arm Group Label: A

Intervention Type: Device

Intervention Name: neck cuff stimulation

Description: Blood pressure receptors in the neck arteries may be stimulated by applying suction through a collar around the neck.

Arm Group Label: A

Intervention Type: Drug

Intervention Name: phenylephrine,isoproterenol,nitroprusside,propranolol,edrophonium,atropine,tyramine

Description: 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

Arm Group Label: A

Intervention Type: Drug

Intervention Name: clonidine,yohimbine,metoclopramide,alpha-methyldopa

Description: Oral Pharmacological Testing clonidine 0.1-0.3 mg, yohimbine 5-10 mg, metoclopramide 10 mg, alpha-methyldopa 62.5 mg, placebo

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: BodPod

Description: Determination of body composition

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Eye exam

Description: Examination of pressure in the eye and eyelid fatiguability. The following eyedrops might be used: 0.5% proparacaine (Alcaine, Allergan, Inc) Fluress (0.4% benoxinate hydrochloride, fluorescein sodium, Akorn, Inc) 0.5%, 1% tropicamide (Mydriacyl, Alcon) Over-the-counter preservative-free artificial tears 0.25%, 2.5% and 10% phenylephrine (Bausch and Lomb) 1% cyclopentolate hydrochloride (Alcon)

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Sleep study

Description: Recording of sleep pattern overnight

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Pain response testing

Description: Subjects will rate the quality and intensity of 2 pain tasks.

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Metabolic chamber

Description: Determination of metabolic rate via 24hr stay in whole-room indirect calorimeter

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Brain function studies

Description: Questionnaires and computer tasks, an EEG and an MRI may be used to assess brain function.

Arm Group Label: A

Intervention Type: Procedure

Intervention Name: Bicycle Exercise Test

Description: Blood pressure and heart rate may be monitored while exercising on a stationary bicycle.

Arm Group Label: A

Eligibility

Criteria:

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

Gender: All

Minimum Age: 12 Years

Maximum Age: 70 Years

Healthy Volunteers: No

Overall Official
Last Name Role Affiliation
Emily M Garland, PhD Principal Investigator Vanderbilt University
Location
Facility: Vanderbilt University
Location Countries

United States

Verification Date

January 2021

Responsible Party

Type: Principal Investigator

Investigator Affiliation: Vanderbilt University Medical Center

Investigator Full Name: Emily M. Garland

Investigator Title: Research Associate Professor

Keywords
Has Expanded Access No
Condition Browse
Number Of Arms 1
Arm Group

Label: A

Type: Experimental

Description: Patients with Orthostatic Hypotension

Study Design Info

Allocation: N/A

Intervention Model: Single Group Assignment

Primary Purpose: Screening

Masking: None (Open Label)

Source: ClinicalTrials.gov

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