Effect of Exercise in OI

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00770484
Recruitment Status : Completed
First Posted : October 10, 2008
Results First Posted : July 9, 2015
Last Update Posted : August 5, 2016
Information provided by (Responsible Party):
Italo Biaggioni, Vanderbilt University

Brief Summary:

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.

Condition or disease Intervention/treatment
Orthostatic Intolerance Postural Tachycardia Syndrome Drug: Propranolol then Placebo Drug: Placebo then Propranolol

Detailed Description:
  • 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.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 12 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Effects of Exercise in Orthostatic Intolerance
Study Start Date : November 2008
Primary Completion Date : May 2015
Study Completion Date : May 2015

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Experimental: Propranolol then placebo
Active treatment
Drug: Propranolol then Placebo
Propanolol 20 mg, given orally within 1 hour prior to exercising
Other Name: Active
Placebo Comparator: Placebo then propranolol
Placebo Treatment
Drug: Placebo then Propranolol
Placebo, matching pill given orally within 1 hour prior to exercising
Other Name: Inactive

Primary Outcome Measures :
  1. Maximal Oxygen Consumption Capacity (VO2 Max) [ Time Frame: Over approximately 30 minutes, within 2 hours of receiving each intervention. ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00770484

United States, Tennessee
Vanderbilt University Medical Center
Nashville, Tennessee, United States, 37232
Sponsors and Collaborators
Vanderbilt University
Principal Investigator: Italo Biaggioni, MD Vanderbilt University

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Italo Biaggioni, Professor of Medicine and Pharmacology, Vanderbilt University Identifier: NCT00770484     History of Changes
Other Study ID Numbers: 080722
First Posted: October 10, 2008    Key Record Dates
Results First Posted: July 9, 2015
Last Update Posted: August 5, 2016
Last Verified: July 2016

Keywords provided by Italo Biaggioni, Vanderbilt University:
Beta blockers

Additional relevant MeSH terms:
Postural Orthostatic Tachycardia Syndrome
Orthostatic Intolerance
Arrhythmias, Cardiac
Heart Diseases
Cardiovascular Diseases
Pathologic Processes
Primary Dysautonomias
Autonomic Nervous System Diseases
Nervous System Diseases
Neurologic Manifestations
Signs and Symptoms
Adrenergic beta-Antagonists
Adrenergic Antagonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Anti-Arrhythmia Agents
Antihypertensive Agents
Vasodilator Agents