POWER (Pulse Width Optimized Waveform Evaluation Trial)

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: NCT00311181
Recruitment Status : Completed
First Posted : April 5, 2006
Results First Posted : August 30, 2012
Last Update Posted : August 30, 2012
Information provided by (Responsible Party):
St. Jude Medical

Brief Summary:
The objective of this study is to compare the ULV (Upper Limit of Vulnerability)/DFT (Defibrillation Threshold) efficacy between the 2.5, 3.5 and 4.5 ms membrane time constant based biphasic defibrillation waveforms. This comparison will result in identifying the optimal membrane time constant when programming the "tuned" defibrillation waveform.

Condition or disease Intervention/treatment Phase
Sudden Cardiac Death Device: Implantable Cardioverter Defibrillator (ICD), Cardiac Resynchronization Therapy (CRT-D) Phase 4

Detailed Description:

Sudden cardiac death (SCD) continues to be a significant cause of cardiac mortality with annual deaths ranging from 250,000 to 400,000 in the United States. Accordingly, implantable cardioverter-defibrillators (ICD's) have proven to be an important therapeutic option for patients susceptible to SCD. Successful therapy and generator longevity are greatly dependent on proper defibrillation threshold (DFT) determination.

All modern ICD's utilize a biphasic waveform for defibrillation. It has been clearly shown that biphasic waveforms reduce the energy required for internal defibrillation of the heart. However, there is no consensus on which pulse widths are best for defibrillation.

St. Jude Medical ICD's (implantable cardioverter defibrillators) have programmable pulse widths, which allow the physician multiple options in dealing with ICD patients. By implanting ICD's with programmable pulse widths, this study utilizes the Tissue RC Resistance/Capacitance) model to try to identify the optimal pulse widths.

To determine the efficacy of an optimal membrane time constant estimate for the "tuned" waveform, defibrillation testing must be performed. Upper limit of vulnerability (ULV) has been proposed as an alternative means of predicting the DFT and it has been shown that ULV guided DFT testing can achieve a defibrillation success rate of 95%.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 217 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
Official Title: Phase 4 Study That Compares the DFT (Defibrillation Threshold) Efficacy of 3 Different Membrane Time Constant Based Biphasic Defibrillation Waveforms
Study Start Date : August 2006
Actual Primary Completion Date : April 2008
Actual Study Completion Date : April 2008

Arm Intervention/treatment
Experimental: 2.5/3.5/4.5 ms defibrillation waveform Device: Implantable Cardioverter Defibrillator (ICD), Cardiac Resynchronization Therapy (CRT-D)
Patients that are indicated for an ICD or CRT-D receive one of these devices.

Primary Outcome Measures :
  1. Defibrillation Thresholds (DFTs) (3.5 ms Waveform) [ Time Frame: Implant ]
  2. DFT (2.5 ms Waveform) [ Time Frame: Implant ]
  3. DFT (4.5 ms Waveform) [ Time Frame: Implant ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Patient is a candidate for ICD/CRT-D implantation.
  • Patient has a compatible transvenous defibrillation lead system.
  • Patient has had an echocardiogram, MUGA, or cath procedure within 6 months of ICD/CRT-D implant.
  • Patient is able to tolerate ULV guided DFT testing.

Exclusion Criteria:

  • Patient has a mechanical valve in the tricuspid position.
  • Patient has epicardial defibrillation electrodes.
  • Patient is pregnant.
  • Patient is less than 18 years old.

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): NCT00311181

United States, Alabama
Baptist Medical Center Montclair
Birmingham, Alabama, United States, 35212
United States, California
Pacific Heart Institute
Santa Monica, California, United States, 90404
Sponsors and Collaborators
St. Jude Medical
Principal Investigator: Shephal Doshi, MD Pacific Heart Institute

Responsible Party: St. Jude Medical Identifier: NCT00311181     History of Changes
Other Study ID Numbers: CRD 324
First Posted: April 5, 2006    Key Record Dates
Results First Posted: August 30, 2012
Last Update Posted: August 30, 2012
Last Verified: July 2012

Keywords provided by St. Jude Medical:

Additional relevant MeSH terms:
Death, Sudden, Cardiac
Pathologic Processes
Heart Arrest
Heart Diseases
Cardiovascular Diseases
Death, Sudden