Pathophysiology of Orthostatic Intolerance | NCT00608725

Studies
Pathophysiology of Orthostatic Intolerance

NCT00608725

Sponsor

Satish R. Raj

Status

Active, not recruiting

Last Update Posted

Oct 8, 2025Actual

Enrollment

260Actual

Phase

Not Applicable

Conditions

Tachycardia
Postural Orthostatic Tachycardia Syndrome

Interventions

DAXOR
QSweat
Intrinsic Heart Rate

Countries

United States

Protocol Section

Identification Module Status Module Sponsor/Collaborators Module Oversight Module Description Module Conditions Module Design Module Arms/Interventions Module Outcomes Module Eligibility Module Contacts/Locations Module References Module IPD Sharing Statement Module

Results Section

Participant Flow Module Baseline Characteristics Module Outcome Measures Module Adverse Events Module More Info Module

Annotation Section

Annotation Module

Document Section

Large Document Module

Derived Section

Miscellaneous Info Module Condition Browse Module Intervention Browse Module

Protocol Section

Identification Module

NCT ID

Results Section

No data available

No data is available for this block.

Annotation Section

No data available

No data is available for this block.

Document Section

No data available

No data is available for this block.

Derived Section

Miscellaneous Info Module

Version Holder

Status Module

Record Verification Date

Oct 2025

Overall Recruitment Status or Expanded Access Status

Active, not recruiting

Last Known Status

Not provided

Delayed Posting

Not provided

Why Stopped

Not provided

Expanded Access Info

Start Date

Dec 1996

Primary Completion Date

Dec 2029Estimated

Completion Date

Dec 2029Estimated

First Submitted Date

Jan 22, 2008

First Submission Date that Met QC Criteria

Feb 5, 2008

First Posted Date

Feb 6, 2008Estimated

Results Waived

Not provided

Results First Submitted Date

Not provided

Results First Submitted that Met QC Criteria

Not provided

Results First Posted Date

Not provided

Certification/Extension (aka Delayed Results) First Submitted Date

Not provided

Certification/Extension First Submitted that Passed QC Review

Not provided

Certification/Extension First Posted Date

Not provided

Last Update Submitted Date

Oct 3, 2025

Last Update Posted Date

Oct 8, 2025Actual

Sponsor/Collaborators Module

Responsible Party, by Official Title

Satish R. Raj, Assistant Professor of Medicine & Pharmacology, Vanderbilt University Medical CenterSponsor-Investigator

Lead Sponsor

Satish R. RajOTHER

Collaborators

Not provided

Oversight Module

Has Data Monitoring Committee (DMC)

Is FDA Regulated Drug

Not provided

Is FDA Regulated Device

Not provided

Is Unapproved Device

Not provided

Pediatric Postmarket Surveillance of a Device Product

Not provided

Product Exported from US

Not provided

FDAAA801 Violation

Not provided

Description Module

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.

Detailed Description

This is not a clinical trial in the classical sense, but an omnibus protocol to allow for disntinct and personalized pathophysiological testing.

Design Module

Study Type

Interventional

Number of References to an Expanded Access Study

Not provided

Expanded Access Types

Not provided

Patient Registry

Not provided

Target Follow-Up Duration

Not provided

Phases

Not Applicable

Interventional Study Design

Allocation

Biospecimen

No data available

No data is available for this block.

Enrollment

260Actual

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
Patients	Other	Patients with orthostatic intolerance	Radiation: DAXOR Procedure: QSweat Drug: Intrinsic Heart Rate
Healthy Control Subjects	Other	Healthy subjects to determine "normal" response	Radiation: DAXOR Procedure: QSweat Drug: Intrinsic Heart Rate

Interventions

Name	Type	Description	Arm Group Labels	Other Names
DAXOR	Radiation	131-I-Human Serum Albumin Blood Volume Assessment Kit	Healthy Control Subjects Patients

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Physiological abnormalities in orthostatic intolerance	varied metrics used here	1 day

Secondary Outcomes

Measure	Description	Time Frame
blood volume	Blood volume as measured by DAXOR technique	1 day
intrinsic heart rate	Heart rate after IV propranolol and IV atropine

Other Outcomes

Not provided

Eligibility Module

Eligibility Criteria

Inclusion Criteria:

Orthostatic intolerance

Exclusion Criteria:

Inability or unwillingness to give informed consent

Accepts Healthy Volunteers

Yes

Sex

All

Sex/Gender Based

Not provided

Sex/Gender Description

Not provided

Minimum Age

18 Years

Maximum Age

80 Years

Standard Ages

AdultOlder Adult

Study Population

Not provided

Sampling Method

Not provided

Contacts/Locations Module

Central Contacts

Not provided

Overall Officials

Name	Affiliation	Role
David Robertson, MD	Vanderbilt University	Principal Investigator

Locations

Facility	Status	City	State	ZIP	Country	Contacts
Vanderbilt University		Nashville	Tennessee	37232	United States

References Module

Citations

PubMed Identifier	Type	Citation	Retractions
21266211	Derived	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.

ID	Term
D001145	Arrhythmias, Cardiac
D006331	Heart Diseases
D002318	Cardiovascular Diseases
D000075224	Cardiac Conduction System Disease

ID	Term
D050198	Phenoxypropanolamines
D011412	Propanolamines
D000605	Amino Alcohols
D000438	Alcohols

ID	Term
D013610	Tachycardia
D054972	Postural Orthostatic Tachycardia Syndrome
D054971	Orthostatic Intolerance