We updated the design of this site on December 18, 2017. Learn more.
ClinicalTrials.gov
ClinicalTrials.gov Menu

Pathophysiology of Orthostatic Intolerance

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00608725
Recruitment Status : Recruiting
First Posted : February 6, 2008
Last Update Posted : March 27, 2017
Sponsor:
Collaborator:
Information provided by (Responsible Party):

Study Description
Brief Summary:
The purpose of this study is to describe the mechanism of orthostatic intolerance, relying on cardiovascular physiological studies. The syndrome is of undetermined etiology, but the syndrome causes impairment of a number of young adults, females more than males, with symptoms of tachycardia, fatigue, lightheadedness, palpitations, blurred vision, chest discomfort, difficulty concentrating, and dizziness with the upright posture. It is believed that many different pathophysiological processes can give rise to this disorder.

Condition or disease Intervention/treatment
Tachycardia Postural Orthostatic Tachycardia Syndrome Radiation: DAXOR Procedure: QSweat Drug: Intrinsic Heart Rate

Study Design

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 100 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Official Title: Pathophysiology of Orthostatic Intolerance
Study Start Date : December 1996
Estimated Primary Completion Date : December 2018
Estimated Study Completion Date : December 2018
Arms and Interventions

Arm Intervention/treatment
Patients
Patients with orthostatic intolerance
Radiation: DAXOR
131-I-Human Serum Albumin Blood Volume Assessment Kit
Other Name: Volumex
Procedure: QSweat
Quantitative Sweat Testing
Other Names:
  • QSART
  • Quantitative Axonal Sudomotor Reflex Testing
Drug: Intrinsic Heart Rate
Atropine 0.04 mg/kg IV in divided doses Propranolol 0.2 mg/kg IV in divided doses
Other Names:
  • Inderal
  • IHR
Healthy Control Subjects
Healthy subjects to determine "normal" response
Radiation: DAXOR
131-I-Human Serum Albumin Blood Volume Assessment Kit
Other Name: Volumex
Procedure: QSweat
Quantitative Sweat Testing
Other Names:
  • QSART
  • Quantitative Axonal Sudomotor Reflex Testing
Drug: Intrinsic Heart Rate
Atropine 0.04 mg/kg IV in divided doses Propranolol 0.2 mg/kg IV in divided doses
Other Names:
  • Inderal
  • IHR


Outcome Measures

Primary Outcome Measures :
  1. Physiological abnormalities in orthostatic intolerance [ Time Frame: 1 day ]

Secondary Outcome Measures :
  1. blood volume [ Time Frame: 1 day ]
  2. intrinsic heart rate [ Time Frame: 1 hour ]
  3. quantitative sweat testing [ Time Frame: 2 hours ]
  4. residual sympathetic function after pharmacological autonomic blockade [ Time Frame: 3 hours ]
  5. norepinephrine spillover [ Time Frame: 3 hours ]

Eligibility Criteria

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Orthostatic intolerance

Exclusion Criteria:

  • Inability or unwillingness to give informed consent
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00608725


Contacts
Contact: Bonnie K Black, BSN CNP 615-343-6499 adc.research@vanderbilt.edu

Locations
United States, Tennessee
Vanderbilt University Recruiting
Nashville, Tennessee, United States, 37232
Principal Investigator: David Robertson, M.D.         
Sub-Investigator: Italo Biaggioni, MD         
Sub-Investigator: Satish R Raj, MD MSCI         
Sponsors and Collaborators
Satish R. Raj
National Institutes of Health (NIH)
Investigators
Principal Investigator: David Robertson, MD Vanderbilt University
More Information

Additional Information:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Satish R. Raj, Assistant Professor of Medicine & Pharmacology, Vanderbilt University Medical Center
ClinicalTrials.gov Identifier: NCT00608725     History of Changes
Other Study ID Numbers: 8398
NIH HL56693
First Posted: February 6, 2008    Key Record Dates
Last Update Posted: March 27, 2017
Last Verified: March 2017

Keywords provided by Satish R. Raj, Vanderbilt University Medical Center:
heart rate
blood pressure
blood volume
sympathetic nervous system
orthostatic tachycardia
orthostatic intolerance
POTS

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