Pathophysiology of Orthostatic Intolerance

This study is currently recruiting participants. (see Contacts and Locations)
Verified January 2013 by Vanderbilt University
Sponsor:
Collaborator:
Information provided by (Responsible Party):
Satish R. Raj, Vanderbilt University
ClinicalTrials.gov Identifier:
NCT00608725
First received: January 22, 2008
Last updated: January 7, 2013
Last verified: January 2013
  Purpose

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 Intervention
Tachycardia
Postural Orthostatic Tachycardia Syndrome
Radiation: DAXOR
Procedure: QSweat
Drug: Intrinsic Heart Rate

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Pathophysiology of Orthostatic Intolerance

Resource links provided by NLM:


Further study details as provided by Vanderbilt University:

Primary Outcome Measures:
  • Physiological abnormalities in orthostatic intolerance [ Time Frame: 1 day ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • 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 ]

Estimated Enrollment: 100
Study Start Date: December 1996
Estimated Study Completion Date: December 2015
Estimated Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

  Eligibility

Ages Eligible for Study:   18 Years to 80 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Orthostatic intolerance

Exclusion Criteria:

  • Inability or unwillingness to give informed consent
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: 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
Investigators
Principal Investigator: David Robertson, MD Vanderbilt University
  More Information

Additional Information:
No publications provided by Vanderbilt University

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Satish R. Raj, Assistant Professor of Medicine & Pharmacology, Vanderbilt University
ClinicalTrials.gov Identifier: NCT00608725     History of Changes
Other Study ID Numbers: 8398, NIH HL56693
Study First Received: January 22, 2008
Last Updated: January 7, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Vanderbilt University:
heart rate
blood pressure
blood volume
sympathetic nervous system
orthostatic tachycardia
orthostatic intolerance
POTS

Additional relevant MeSH terms:
Orthostatic Intolerance
Mitral Valve Prolapse
Neurocirculatory Asthenia
Tachycardia
Postural Orthostatic Tachycardia Syndrome
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases
Neurologic Manifestations
Signs and Symptoms
Heart Valve Prolapse
Heart Valve Diseases
Heart Diseases
Cardiovascular Diseases
Anxiety Disorders
Mental Disorders
Arrhythmias, Cardiac
Pathologic Processes

ClinicalTrials.gov processed this record on July 22, 2014