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Trial record 38 of 132 for:    "Paroxysmal Ventricular Fibrillation"

Comparison of VF Induction Techniques During Medtronic ICD Implant (VF) (ICD) (VF)

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: NCT02027883
Recruitment Status : Completed
First Posted : January 6, 2014
Results First Posted : December 30, 2014
Last Update Posted : May 22, 2018
Information provided by (Responsible Party):
James Merrill, Wellmont CVA Heart Institute

Brief Summary:

As the indications for Implantable Cardioverter Defibrillator implantation expand, minimizing implant time is critical. Also, patients receiving biventricular ICDs are sometimes more unstable and minimization of sedation time is crucial. Multiple induction attempts, with a 1-Joule shock, can cause disruption in lead position. Therefore limiting the number of attempts will allow for better lead stability throughout the procedure and a more straightforward implant process.

Investigator proposes a detailed documentation of success rates from various Ventriculart Fibrillation induction methods during implant of Medtronic defibrillation capable devices.

Condition or disease Intervention/treatment Phase
Cardiomyopathy Device: Nominal T shock setting Device: Educated T shock setting Not Applicable

Detailed Description:

Our clinical experience has found that attempts to induce patients receiving ICDs at implant using the nominal Medtronic T-shock settings are not always effective at inducing ventricular fibrillation. When this results, a change to the parameters for T-shock is made before reattempting to induce ventricular fibrillation in patients undergoing ICD implantation.

Another available induction method is 50 Hz Burst. "The 50 Hz Burst induction is designed to induce VF by delivering a rapid burst of pacing pulses. The amplitude and pulse width of these pulses are selectable, but the pacing interval is fixed at 20 ms."2 If multiple attempts using the T-shock method are unsuccessful, 50 Hz Burst provides an additional method for inducing ventricular fibrillation. It is a less desirable method since it can result in very fine VF that is difficult to identify the initiation of possibly resulting in longer times in VF causing higher defibrillation threshold or in undersensing due to the fine nature of the rhythm.

T-shock has been found to be a fast and reliable method for inducing ventricular fibrillation in ICD implants. Greater success of inducing ventricular fibrillation using the T-shock method has been found when the energy of the T-shock was higher and the coupling interval was shorter. In addition, increasing the shock strength increases the window of vulnerability. For the T-shock method to be most efficient, initial success at inducing ventricular fibrillation, and therefore a reduced number of attempts, is important. This requires a better understanding of the optimal programmed settings for the initial T-shock induction attempt.

Moreover, in recent years, ICD indications have grown to include primary prevention patients. These patients may have different vulnerable periods than patients previously evaluated to develop Medtronic nominal settings.

Our clinical experience has found that the nominal T-shock settings are only effective at inducing ventricular fibrillation approximately seventy-five percent of the time. However, a detailed collection of success rates has not been performed.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 100 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Comparison of Ventricular Fibrillation Induction Techniques During Medtronic Implantable Cardioverter Defibrillator Implant
Study Start Date : January 2011
Actual Primary Completion Date : August 2012
Actual Study Completion Date : August 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Shock

Arm Intervention/treatment
Active Comparator: Nominal Parameter
Nominal T shock setting
Device: Nominal T shock setting
Nominal Parameter Set 1 Programming Values for EnTrust
Other Name: Medtronic ICDs

Experimental: Experimental Parameter
Educated T shock setting
Device: Educated T shock setting
Experimental Parameter Set 2 Programming Values
Other Name: Medtronic ICDs

Primary Outcome Measures :
  1. Sustained Ventricular Fibrillation [ Time Frame: 2 hours ]
    The primary endpoint is the successful induction of sustained ventricular fibrillation.

Secondary Outcome Measures :
  1. Factors [ Time Frame: 2 hours ]
    Determine if any pre-implant patient demographics are factors impacting T-shock success according to parameter settings.

Other Outcome Measures:
  1. Safety Monitoring [ Time Frame: 2 hours ]
    Number of participants that were monitored for safety issues, including increased heart rate, blood pressure, decreased oximetry levels, and stable rhythm during the entire procedure.

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:

  • All patients undergoing Medtronic ICD or Cardiac Resynchronization Therapy-Defibrillator implant (initial implant or generator replacement) will be included.

Exclusion Criteria:

  • Any patient who is medically unstable and testing is deemed unsafe by physician will be excluded from this study.

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): NCT02027883

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United States, Tennessee
Wellmont CVA Heart Institute
Kingsport, Tennessee, United States, 37660
Sponsors and Collaborators
James Merrill

Bardy G, Mehra R, Johnson G, Kudenchuk P, Dolack G, Poole J, Hofer B: Low energy pulsing on the T-wave: A new programming method for intentional, device mediated induction of ventricular fibrillation for defibrillation testing. PACE 15(4, Pt II): 562, 1992.
Marquis DR Reference Manual, Medtronic, Inc.
Mitchell L, Yee R, Talajic M, Newman D, Sheldon R, Kerr C, Kus T, Boyle A, Canadian Jewel PCD Investigators: Low-energy, T-wave synchronous, interval shock for rapid, reliable ventricular fibrillation induction by an implantable cardioverter defibrllattor. PACE, 17(4, Pt II): 851, 1994.
Swartz J, Stanton M, DeGroot P, Mehra R: Influence of T-wave shock energy on ventricular fibrillation vulnerability in humans. JACC 1995 Conference Abstracts: 214A, 1995.

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Responsible Party: James Merrill, James Merrill, MD, FACC, Wellmont CVA Heart Institute Identifier: NCT02027883     History of Changes
Other Study ID Numbers: VF Induction
First Posted: January 6, 2014    Key Record Dates
Results First Posted: December 30, 2014
Last Update Posted: May 22, 2018
Last Verified: April 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by James Merrill, Wellmont CVA Heart Institute:
Ventricular Fibrillation Induction Testing

Additional relevant MeSH terms:
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Ventricular Fibrillation
Heart Diseases
Cardiovascular Diseases
Arrhythmias, Cardiac
Pathologic Processes