Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome - Full Text View

Purpose

The purpose of this study is to see if people with Postural Tachycardia Syndrome (POTS) have different levels of certain chemicals in their blood than people who don't have POTS. This study will test whether the blood vessels of people with POTS will react differently to certain tests than people without POTS.

The hypothesis of the study is:

Patients with POTS will have vascular endothelial dysfunction compared with control subjects.

Condition	Intervention
Postural Tachycardia Syndrome	Device: Blood Pressure and Blood Flow

Study Type:	Observational
Study Design:	Time Perspective: Cross-Sectional
Official Title:	Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome (POTS)

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Further study details as provided by Vanderbilt University:

Primary Outcome Measures:

RH-PAT index [ Time Frame: The study will be complete in approximately 2 hours. There is no follow-up to this study. ] [ Designated as safety issue: No ]
The primary analysis of RH-PAT will involve a non-parametric, Mann Whitney U test of RH-PAT between POTS patients and Control subjects.

Secondary Outcome Measures:

Comparison of continuous outcome measures between POTS patients and controls [ Time Frame: The study will be complete in approximately 2 hours. there is no follow-up to this study. ] [ Designated as safety issue: No ]
Secondary analysis will include non-parametric between group (POTS vs Controls) comparisons of continuous outcome measures. RH-PAT, CBF-RH, Framingham Risk Score, Homeostasis Model Assessment (HOMA) insulin resistance, Oxidative Stress, Inflammatory markers, and Other blood paramters.

Estimated Enrollment:	57
Study Start Date:	February 2011
Estimated Study Completion Date:	February 2015
Estimated Primary Completion Date:	February 2015 (Final data collection date for primary outcome measure)

Groups/Cohorts	Assigned Interventions
POTS & Controls Participants will have a physical prior to the study day and collect urine for 24 hours. On the study day the following procedures take place: After blood samples taken (about 2 tbsp), the subject will lie down. A blood pressure cuff will be placed on one arm and small probes on one finger on both hands. The arm blood pressure cuff will be inflated 60 points above the highest number on your normal blood pressure. A cuff will be place above the left calf and knee. The blood pressure and calf blood flow will be measured for one minute. the lower leg cuff will be inflated after 1 minute, then the cuff will be deflated. The blood pressure and forearm blood flow will be recorded. Next, the cuff on the upper leg will be inflated for 5 minutes. At the end of 5 minutes, the cuff will be released and the measurements of blood pressure and calf blood flow will be repeated. The study lasts about 2 hours.	Device: Blood Pressure and Blood Flow A blood pressure cuff will be placed on one arm and small probes on one finger on both hands. The probes also measure blood pressure. After 10 minutes, the arm blood pressure cuff will be inflated. The cuff will stay inflated for 5 minutes, then the air will be let out. A cuff will be place above the left calf and the left knee. The subject will lie quietly for 9 minutes, then blood pressure and calf blood flow will be measured for one minute. the lower leg cuff will be inflated after 1 minute, then the cuff will be deflated. The blood pressure and forearm blood flow will be recorded. Next, the cuff on the upper leg will be inflated for 5 minutes then, it will be released and the measurements of blood pressure and calf blood flow will be repeated. The study lasts about 2 hours. Other Name: Pulsitile Arterial Tonometry Protocol (PAT)

Groups/Cohorts

Assigned Interventions

POTS & Controls

Participants will have a physical prior to the study day and collect urine for 24 hours.

On the study day the following procedures take place:

After blood samples taken (about 2 tbsp), the subject will lie down. A blood pressure cuff will be placed on one arm and small probes on one finger on both hands. The arm blood pressure cuff will be inflated 60 points above the highest number on your normal blood pressure. A cuff will be place above the left calf and knee. The blood pressure and calf blood flow will be measured for one minute. the lower leg cuff will be inflated after 1 minute, then the cuff will be deflated. The blood pressure and forearm blood flow will be recorded. Next, the cuff on the upper leg will be inflated for 5 minutes. At the end of 5 minutes, the cuff will be released and the measurements of blood pressure and calf blood flow will be repeated.

The study lasts about 2 hours.

Device: Blood Pressure and Blood Flow

A blood pressure cuff will be placed on one arm and small probes on one finger on both hands. The probes also measure blood pressure. After 10 minutes, the arm blood pressure cuff will be inflated. The cuff will stay inflated for 5 minutes, then the air will be let out. A cuff will be place above the left calf and the left knee. The subject will lie quietly for 9 minutes, then blood pressure and calf blood flow will be measured for one minute. the lower leg cuff will be inflated after 1 minute, then the cuff will be deflated. The blood pressure and forearm blood flow will be recorded. Next, the cuff on the upper leg will be inflated for 5 minutes then, it will be released and the measurements of blood pressure and calf blood flow will be repeated.

The study lasts about 2 hours.

Other Name: Pulsitile Arterial Tonometry Protocol (PAT)

Eligibility

Ages Eligible for Study:	18 Years to 60 Years
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes
Sampling Method:	Probability Sample

Study Population

Patients with Postural Tachycardia Syndrome

Controls will be age & sex matched to the patients with POTS

Criteria

Inclusion Criteria:

ALL:

Ages between 18-60 years old
Male and female subjects are eligible
Able and willing to give informed consent

Additional criteria for POTS:

Diagnosed with postural tachycardia syndrome by the Vanderbilt Autonomic - Dysfunction Center (1. increase in heart rate >/= 30 beats/minute with position change from supine to standing for 10 minutes and/or 2. Chronic symptoms consistent with POTS that are worse when upright and get better with recumbence.

Additional criteria for Control subjects:

Healthy, non-obese, non-smokers without orthostatic tachycardia
Selected to match profiles of POTS patients (gender, age)
Not using vasoactive medications

Exclusion Criteria:

Overt cause for postural tachycardia (such as acute dehydration)
Inability to give, or withdraw informed consent
Pregnancy
Other factors in the investigator's opinion would prevent the subject from completing the study

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT01308099

Contacts

Contact: Satish Raj, MD, MSCI	615-322-2931	adcresearch@vanderbilt.edu
Contact: Alfredo Gamboa, MD	615-322-2931	adcresearch@vanderbilt.edu

Locations

United States, Tennessee
Vanderbilt University	Recruiting
Nashville, Tennessee, United States, 37232
Principal Investigator: Satish Raj, MD, MSCI

Sponsors and Collaborators

Vanderbilt University

More Information

Additional Information:

Vanderbilt Autonomic Dysfunction Center List of Current Research Projects This link exits the ClinicalTrials.gov site

Publications:

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Higashi Y, Sasaki S, Nakagawa K, Matsuura H, Kajiyama G, Oshima T. A noninvasive measurement of reactive hyperemia that can be used to assess resistance artery endothelial function in humans. Am J Cardiol. 2001 Jan 1;87(1):121-5, A9.

Wilkinson IB, Qasem A, McEniery CM, Webb DJ, Avolio AP, Cockcroft JR. Nitric oxide regulates local arterial distensibility in vivo. Circulation. 2002 Jan 15;105(2):213-7.

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Nohria A, Gerhard-Herman M, Creager MA, Hurley S, Mitra D, Ganz P. Role of nitric oxide in the regulation of digital pulse volume amplitude in humans. J Appl Physiol. 2006 Aug;101(2):545-8. Epub 2006 Apr 13.

Bonetti PO, Pumper GM, Higano ST, Holmes DR Jr, Kuvin JT, Lerman A. Noninvasive identification of patients with early coronary atherosclerosis by assessment of digital reactive hyperemia. J Am Coll Cardiol. 2004 Dec 7;44(11):2137-41.

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Responsible Party:	Satish R. Raj, Assistant Professor of Medicine, Vanderbilt University
ClinicalTrials.gov Identifier:	NCT01308099 History of Changes
Other Study ID Numbers:	091332
Study First Received:	February 18, 2011
Last Updated:	January 7, 2013
Health Authority:	United States: Institutional Review Board

Keywords provided by Vanderbilt University:

POTS
Vascular Endothelial Function

Additional relevant MeSH terms:

Tachycardia
Postural Orthostatic Tachycardia Syndrome
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases

Pathologic Processes
Orthostatic Intolerance
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases

ClinicalTrials.gov processed this record on May 23, 2013