Now Available for Public Comment: Notice of Proposed Rulemaking (NPRM) for FDAAA 801 and NIH Draft Reporting Policy for NIH-Funded Trials

Pathophysiology of Orthostatic Intolerance

This study is currently recruiting participants. (see Contacts and Locations)
Verified January 2013 by Vanderbilt University
Information provided by (Responsible Party):
Satish R. Raj, Vanderbilt University Identifier:
First received: January 22, 2008
Last updated: January 7, 2013
Last verified: January 2013

January 22, 2008
January 7, 2013
December 1996
December 2015   (final data collection date for primary outcome measure)
Physiological abnormalities in orthostatic intolerance [ Time Frame: 1 day ] [ Designated as safety issue: No ]
Same as current
Complete list of historical versions of study NCT00608725 on Archive Site
  • blood volume [ Time Frame: 1 day ] [ Designated as safety issue: No ]
  • intrinsic heart rate [ Time Frame: 1 hour ] [ Designated as safety issue: No ]
  • quantitative sweat testing [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
  • residual sympathetic function after pharmacological autonomic blockade [ Time Frame: 3 hours ] [ Designated as safety issue: No ]
  • norepinephrine spillover [ Time Frame: 3 hours ] [ Designated as safety issue: No ]
Same as current
Not Provided
Not Provided
Pathophysiology of Orthostatic Intolerance
Pathophysiology of Orthostatic Intolerance

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.

Not Provided
Not Provided
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
  • Tachycardia
  • Postural Orthostatic Tachycardia Syndrome
  • 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
  • Patients
    Patients with orthostatic intolerance
    • Radiation: DAXOR
    • Procedure: QSweat
    • Drug: Intrinsic Heart Rate
  • Healthy Control Subjects
    Healthy subjects to determine "normal" response
    • Radiation: DAXOR
    • Procedure: QSweat
    • Drug: Intrinsic Heart Rate
Mustafa HI, Garland EM, Biaggioni I, Black BK, Dupont WD, Robertson D, Raj SR. Abnormalities of angiotensin regulation in postural tachycardia syndrome. Heart Rhythm. 2011 Mar;8(3):422-8. doi: 10.1016/j.hrthm.2010.11.009. Epub 2011 Jan 22.

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
December 2015
December 2015   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • Orthostatic intolerance

Exclusion Criteria:

  • Inability or unwillingness to give informed consent
18 Years to 80 Years
Contact: Bonnie K Black, BSN CNP 615-343-6499
United States
8398, NIH HL56693
Satish R. Raj, Vanderbilt University
Satish R. Raj
National Institutes of Health (NIH)
Principal Investigator: David Robertson, MD Vanderbilt University
Vanderbilt University
January 2013

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP