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Completed

NCT Number: NCT00770484

Effect of Exercise in OI

The main limitation patients with orthostatic intolerance (OI, or postural tachycardia syndrome, POTS) have to exercise is related to their increase in heart rate when standing. Main pharmacological treatment today is aimed at reducing heart rate with the use of betablockers (propanolol), this theoretically could also improve their exercise capacity; if their heart rate do not increase as much with the medication, they could exercise more. In addition, it has been suggested that in healthy volunteers subjected to head down tilt for 2 weeks (situation that produces a "simulated" transient POTS-like state) a single bout of intense exercise can improve orthostatic tolerance the day after exercising. The mechanisms involved in such response are not that clear but could be an increase in plasma volume already diminished in POTS patients. It seems likely that the same could be true for POTS patients.

The purpose of the present study are to pharmacologically improve the amount of exercise POTS patients can perform by reducing their baseline heart rate (specific aim 1) and to evaluate next day heart responses to an acute bout of intense exercise.

Therefore, the specific aims of this study are:

1. To test the hypothesis that lowering heart rate response with propanolol will result in an increase in exercise capacity. 2. To test the hypothesis that a single bout of exercise will result in an improvement in orthostatic tolerance the day after exercising.

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Key information

Conditions

Orthostatic Intolerance Autonomic Nervous System Diseases Behavior Motor Activity Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Postural Orthostatic Tachycardia Syndrome Postural Tachycardia Syndrome Primary Dysautonomias Signs and Symptoms

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Vanderbilt University Medical Center

Nashville, Tennessee, 37232, United States

About this study

  • Subjects will be studied twice, once after receiving placebo and in a second occasion after receiving propanolol.
  • An exercise capacity test with estimation of maximal oxygen consumption (VO2 max) will be done within 1 hour of receiving a pill containing placebo and that will be in appearance identical to the one for propanolol. This test will be conducted on a stationary bicycle and the effort will be gradually increased while expired air is measured during exhaustive physical work. The test will last approximately 30 minutes and be conducted in Vanderbilt's Clinical Trial Center.
  • The day before and the day after the exercise test subjects will be asked to collect urine for 12 hours each time and to keep a record of how much liquid they ingest.
  • Posture study tests (measurements of heart rate and blood pressure taken while lying down and at intervals for up to 30 minutes while standing) will be done the day before and the day after the exercise test.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Meet diagnostic criteria of POTS (Raj, et al., 2005)
  • Age between 18-65 years
  • Male and female are eligible (although the majority of patients POTS are female).
  • Able and willing to provide informed consent

Exclusion criteria

  • Presence of medical conditions that can explain postural tachycardia (e.g., dehydration, medications)
  • Pregnancy
  • Other factors which in the investigator's opinion would prevent the subject from completing the protocol.
  • Patients who are bedridden or chair-ridden.

Treatment and study plan

Propranolol then Placebo

Drug

Propanolol 20 mg, given orally within 1 hour prior to exercising

Other names: Active

Placebo then Propranolol

Drug

Placebo, matching pill given orally within 1 hour prior to exercising

Other names: Inactive

Primary outcomes

  1. Maximal Oxygen Consumption Capacity (VO2 Max)

    Time frame: Over approximately 30 minutes, within 2 hours of receiving each intervention.

Sponsors and collaborators

Lead sponsor

Vanderbilt University

Other

Registry information

Official study title

Effects of Exercise in Orthostatic Intolerance

Important dates

Study start
2008
Primary completion
2015
Study completion
2015
First posted
Oct 10, 2008
Registry last updated
Aug 5, 2016

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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