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Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects

Primary Purpose

Long QT Syndrome, Cardiac Repolarization

Status
Completed
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Placebo
Propranolol LA
Sponsored by
MetroHealth Medical Center
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Long QT Syndrome focused on measuring QT interval, beta-blocker, exercise, electrocardiogram, repolarizaton

Eligibility Criteria

18 Years - 55 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • Healthy normal adults, age- and gender-matched to previously studied LQT1 subjects

Exclusion Criteria:

  • Cardiac disease
  • Diabetes
  • Hypertension
  • Severe allergic reaction
  • Asthma requiring treatment
  • Use of medications other than oral contraceptives, acetaminophen, nonsteroidal anti-inflammatory drugs, or synthroid or other thyroid medications
  • Pregnancy (subjects will be asked if they are pregnant)
  • Inability to sign informed consent

Sites / Locations

    Arms of the Study

    Arm 1

    Arm 2

    Arm Type

    Placebo Comparator

    Active Comparator

    Arm Label

    1

    2

    Arm Description

    Subjects are assigned to placebo.

    Subjects will take propranolol LA 80 mg daily for one week then 160 mg for one week followed by the exercise test.

    Outcomes

    Primary Outcome Measures

    QTc Response to Exercise on Versus Off Beta-blocker.
    To minimize the effect of heart rate on QT, QT was measured at heart rates between 100 and 110 beats per minute during exercise (on and off beta-blocker) and during recovery (on and off beta-blocker).

    Secondary Outcome Measures

    Tpeak-end Interval (Tpe)
    Tpeak-end interval was measured at rest, exercise, and recovery on placebo and on propranolol.

    Full Information

    First Posted
    December 26, 2007
    Last Updated
    July 29, 2013
    Sponsor
    MetroHealth Medical Center
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    1. Study Identification

    Unique Protocol Identification Number
    NCT00588965
    Brief Title
    Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects
    Official Title
    Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects
    Study Type
    Interventional

    2. Study Status

    Record Verification Date
    July 2013
    Overall Recruitment Status
    Completed
    Study Start Date
    August 2007 (undefined)
    Primary Completion Date
    December 2008 (Actual)
    Study Completion Date
    December 2008 (Actual)

    3. Sponsor/Collaborators

    Responsible Party, by Official Title
    Principal Investigator
    Name of the Sponsor
    MetroHealth Medical Center

    4. Oversight

    Data Monitoring Committee
    No

    5. Study Description

    Brief Summary
    Background. In congenital long QT syndrome type 1 (LQT1), episodes of ventricular tachycardia are usually triggered by exercise and can be prevented in most patients by beta-blocker therapy. In addition, LQT1 associated with a normal resting QT interval can be unmasked by the abnormal QT response to exercise testing (failure of the QT interval to shorten normally). Preliminary data from our laboratory show that the exercise QT intervals of patients with LQT1 are partially normalized by beta-blocker therapy. It is still currently not known if beta-blockers modify the QT/heart rate relationship (a primary effect on repolarization) or if the "normalizing" effect is due to the inability of subjects on beta-blockers to attain sufficiently high workloads (due to reduced heart rate) for prolongation to occur. Moreover, the physiologic response of the exercise QT interval to beta-blockers in healthy control subjects is not known. Objective. The objective of this study is to define the impact of beta-blocker therapy on the QT response to exercise and recovery in normal subjects. Methods. Approximately 36 healthy adult subjects age-matched to previously studied LQT1 subjects will undergo 1) screening history, 2) two weeks of beta-blocker therapy ending in an exercise test, and 3) two weeks of placebo therapy ending in an exercise test. Beta blocker and placebo will be given in random order in a double-blind fashion. The QT response to exercise and recovery will be compared between drug-free and beta-blocker-treated states. These data will be compared to those previously collected for LQT1 subjects. Implications. These results will provide new information about the effect of beta-blocker therapy on repolarization parameters in normal subjects, and will provide a context in which to interpret the previous findings that beta-blocker administration modifies the QT response to exercise in LQT1 subjects.

    6. Conditions and Keywords

    Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
    Long QT Syndrome, Cardiac Repolarization
    Keywords
    QT interval, beta-blocker, exercise, electrocardiogram, repolarizaton

    7. Study Design

    Primary Purpose
    Basic Science
    Study Phase
    Not Applicable
    Interventional Study Model
    Crossover Assignment
    Masking
    ParticipantInvestigator
    Allocation
    Randomized
    Enrollment
    36 (Actual)

    8. Arms, Groups, and Interventions

    Arm Title
    1
    Arm Type
    Placebo Comparator
    Arm Description
    Subjects are assigned to placebo.
    Arm Title
    2
    Arm Type
    Active Comparator
    Arm Description
    Subjects will take propranolol LA 80 mg daily for one week then 160 mg for one week followed by the exercise test.
    Intervention Type
    Drug
    Intervention Name(s)
    Placebo
    Intervention Description
    Placebo will be given 1 pill daily for a week, then 2 pills daily, followed by the exercise test.
    Intervention Type
    Drug
    Intervention Name(s)
    Propranolol LA
    Intervention Description
    Subjects will receive propranolol LA 80 mg one pill daily for 1 week then 2 pills daily for 1 week followed by exercise test.
    Primary Outcome Measure Information:
    Title
    QTc Response to Exercise on Versus Off Beta-blocker.
    Description
    To minimize the effect of heart rate on QT, QT was measured at heart rates between 100 and 110 beats per minute during exercise (on and off beta-blocker) and during recovery (on and off beta-blocker).
    Time Frame
    2 weeks on each treatment then exercise test
    Secondary Outcome Measure Information:
    Title
    Tpeak-end Interval (Tpe)
    Description
    Tpeak-end interval was measured at rest, exercise, and recovery on placebo and on propranolol.
    Time Frame
    Measured after 2 weeks on each intervention

    10. Eligibility

    Sex
    All
    Minimum Age & Unit of Time
    18 Years
    Maximum Age & Unit of Time
    55 Years
    Accepts Healthy Volunteers
    Accepts Healthy Volunteers
    Eligibility Criteria
    Inclusion Criteria: Healthy normal adults, age- and gender-matched to previously studied LQT1 subjects Exclusion Criteria: Cardiac disease Diabetes Hypertension Severe allergic reaction Asthma requiring treatment Use of medications other than oral contraceptives, acetaminophen, nonsteroidal anti-inflammatory drugs, or synthroid or other thyroid medications Pregnancy (subjects will be asked if they are pregnant) Inability to sign informed consent
    Overall Study Officials:
    First Name & Middle Initial & Last Name & Degree
    Elizabeth S Kaufman, MD
    Organizational Affiliation
    MetroHealth Medical Center
    Official's Role
    Principal Investigator

    12. IPD Sharing Statement

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    Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects

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