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Exercise After an ICD

This study has been completed.
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Cindy Dougherty, University of Washington Identifier:
First received: August 27, 2007
Last updated: November 7, 2014
Last verified: November 2014
An implantable cardioverter-defibrillator (ICD) is a small device that is surgically implanted in the chest or abdomen and uses electrical pulses or shocks to help control life-threatening, irregular heartbeats. Increasing aerobic exercise may provide health benefits to people with ICDs. This study will examine the effects of an exercise program on heart and lung function in people who have an ICD.

Condition Intervention Phase
Defibrillators, Implantable
Heart Failure, Congestive
Behavioral: Aerobic Exercise Program
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Anti-Arrhythmic Effects of Exercise After an Implantable Cardioverter Defibrillator (ICD)

Resource links provided by NLM:

Further study details as provided by University of Washington:

Primary Outcome Measures:
  • Cardiopulmonary function [ Time Frame: Measured at Week 8 ]

Secondary Outcome Measures:
  • Heart rate variability [ Time Frame: Measured at Week 8 ]
  • Quality of life [ Time Frame: Measured at Weeks 8 and 24 ]
  • Anxiety [ Time Frame: Measured at Weeks 8 and 24 ]
  • Depression [ Time Frame: Measured at Weeks 8 and 24 ]
  • Interleukin-6 (IL-6) [ Time Frame: Measured at Weeks 8 and 24 ]
  • B-type natriuretic peptide (BNP) [ Time Frame: Measured at Weeks 8 and 24 ]
  • ICD shocks [ Time Frame: Measured at Weeks 8 and 24 ]
  • Tissue necrosis factor-alpha (TNF-alpha) [ Time Frame: Measured at Weeks 8 and 24 ]

Enrollment: 160
Study Start Date: November 2007
Study Completion Date: June 2014
Primary Completion Date: June 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Aerobic Exercise Program Behavioral: Aerobic Exercise Program
Home walking 1 hour a day for 5 days/week for 8 weeks. Then 30 minutes a day on all or most days of the week.
No Intervention: Usual Care

Detailed Description:

An ICD is a device designed to quickly detect a life-threatening, rapid heartbeat. Through a process called defibrillation, the ICD tries to convert an abnormal heart rhythm back to normal by delivering an electrical shock to the heart. The ICD continuously monitors heartbeats to ensure that they are normal, and it only delivers a shock to the heart when it senses a life-threatening rhythm. People who have experienced ventricular fibrillation, which is a severely abnormal heart rhythm, or ventricular tachycardia, which is a rapid heart beat that begins in the bottom chambers of the heart, are common recipients of an ICD. Other potential ICD recipients include people who have survived a heart attack, but have weak hearts; people with heart muscle problems; and people with reduced pumping function in their heart. People who have ICDs may benefit from aerobic exercise to improve their physical fitness and overall health. The purpose of this study is to evaluate the effectiveness of an exercise program at improving heart and lung function in people who have an ICD.

In this 6-month study, participants will be randomly assigned to either take part in the exercise program or receive usual care. At a baseline study visit, all participants will complete an exercise treadmill test, wear a Holter monitor to record heart activity for 24 hours, undergo blood collection, and complete questionnaires to assess quality of life, anxiety, and depression. Participants taking part in the exercise program will receive 1 hour of exercise education over the telephone. During Weeks 1 through 8, participants will stretch for 10 minutes and walk 1 hour daily for 5 days a week; during Weeks 9 through 24, participants will walk 30 minutes daily for 5 days a week. Participants will wear a Polar Heart Rate monitor to record their heart rate and a pedometer to keep track of the number of steps walked. They will also record details of their exercise in a daily activity log. Throughout the entire study, a study nurse will call participants on a weekly basis to check on their progress and to help resolve any exercise-related problems. At Weeks 8 and 24, all participants including those receiving usual care, will attend a study visit for repeat baseline evaluations. Study researchers will review medical records to collect various information, including the reason for needing an ICD, the type and settings of the ICD, medication use, medical history, current health problems, lab test results, echocardiogram images of the heart, and electrocardiogram (EKG) results.


Ages Eligible for Study:   21 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • ICD implanted in the 12 months prior to study entry
  • Currently taking beta blocker medication
  • Speaks and reads English

Exclusion Criteria:

  • Unstable angina, heart attack, or percutaneous coronary intervention (PCI) in the 3 months prior to study entry
  • Experienced an ICD shock in the 3 months prior to study entry
  • Currently exercises 3 times a week for 20 minutes a day
  • Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) score for alcohol consumption greater than 4
  • Shore Blessed score for cognitive dysfunction greater than 6
  Contacts and Locations
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Please refer to this study by its identifier: NCT00522340

United States, Washington
University of Washington
Seattle, Washington, United States, 98195
Sponsors and Collaborators
University of Washington
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Cynthia Dougherty, ARNP, PhD University of Washington
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Cindy Dougherty, Professor, Biobehavioral Nursing and Health Systems, University of Washington Identifier: NCT00522340     History of Changes
Other Study ID Numbers: 31202-B
R01HL084550-01A1 ( US NIH Grant/Contract Award Number )
Study First Received: August 27, 2007
Last Updated: November 7, 2014

Keywords provided by University of Washington:
Implantable Cardioverter Defibrillators

Additional relevant MeSH terms:
Heart Failure
Heart Diseases
Cardiovascular Diseases processed this record on April 26, 2017