Assessment of Vascular Endothelial Function in Postural Tachycardia Syndrome

Vanderbilt University Medical Center

Status: Completed

Conditions: Postural Tachycardia Syndrome

Treatments: Device: Blood Pressure and Blood Flow

Study type: Observational

Funder types: Other

Identifiers

NCT01308099

091332

Details and patient eligibility

About

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.

Enrollment: 26 patients

Sex: All

Ages: 18 to 60 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

26 participants in 1 patient group

POTS & Controls

Description:

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 for five minutes. The blood pressure and forearm blood flow will be recorded. 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 brachial artery diameter and flow will be measured at baseline, during cuff inflation and for 3 minutes after deflation. The study lasts about 2 hours.

Treatment:

Device: Blood Pressure and Blood Flow