CardiomyopathyVFNCT02027883
Comparison of VF Induction Techniques During Medtronic ICD Implant (VF) (ICD)
A study testing Nominal T shock setting and Educated T shock setting in people with Cardiomyopathy, run by James Merrill at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Cardiomyopathy
- What is being tested?
- Nominal T shock setting and Educated T shock setting
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- Jan 2011to Aug 2012
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- All patients undergoing Medtronic ICD or Cardiac Resynchronization Therapy-Defibrillator implant (initial implant or generator replacement) will be included.
Who cannot join
- Any patient who is medically unstable and testing is deemed unsafe by physician will be excluded from this study.
Trial locations and contacts
1 site in 1 country.
United States1 site
Wellmont CVA Heart Institute
Kingsport, Tennessee, 37660
About this study
Official title: Comparison of Ventricular Fibrillation Induction Techniques During Medtronic Implantable Cardioverter Defibrillator Implant
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.
Read the 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.
- Conditions
- Cardiomyopathy
- Being tested
- Nominal T shock setting, Educated T shock setting
- Keywords
- Defibrillators, Ventricular Fibrillation Induction Testing
- Medical subject headings
- Cardiomyopathies
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nominal T shock settingDevice
Also called Medtronic ICDs
Nominal Parameter Set 1 Programming Values for EnTrust
Educated T shock settingDevice
Also called Medtronic ICDs
Experimental Parameter Set 2 Programming Values
| Study group | Role | What they receive |
|---|---|---|
| Nominal Parameter | Active comparator | Nominal T shock setting Receives: Device: Nominal T shock setting |
| Experimental Parameter | Experimental | Educated T shock setting Receives: Device: Educated T shock setting |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sustained Ventricular Fibrillation
The primary endpoint is the successful induction of sustained ventricular fibrillation.
Measured: 2 hours
Secondary outcomes (1)
Factors
Determine if any pre-implant patient demographics are factors impacting T-shock success according to parameter settings.
Measured: 2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Jan 2014 (estimated)
- Study startJan 2011
- Primary completionAug 2012
- Study completionAug 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for CardiomyopathyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 100 participants (actual)
Sponsor and investigators
- Lead sponsor
- James Merrill
- Sponsor type
- University, hospital or other
- Collaborators
- Medtronic
- Responsible party
- Sponsor-investigator, James Merrill, Wellmont CVA Heart Institute
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02027883
- Sponsor's protocol ID
- VF Induction
- Acronym
- VF
- Status last verified
- Apr 2018
- First submitted
- 31 Dec 2013
- Last updated
- 22 May 2018
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
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.
Bhandari AK, Isber N, Estioko M, Ziccardi T, Cannom DS, Park Y, Lerman RD, Prejean C, Sun GW. Efficacy of low-energy T wave shocks for induction of ventricular fibrillation in patients with implantable cardioverter defibrillators. J Electrocardiol. 1998 Jan;31(1):31-7. doi: 10.1016/s0022-0736(98)90004-8.
PubMed 9533375Marquis 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.
Study at a glance
From the registry record, last updated by the sponsor on 22 May 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Ventricular Fibrillation Induction Techniques During Medtronic Implantable Cardioverter Defibrillator Implant
- ClinicalTrials.gov ID
- NCT02027883
- Acronym / sponsor ID
- VF / VF Induction
- Conditions
- Cardiomyopathy
- Keywords
- Defibrillators, Ventricular Fibrillation Induction Testing
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 100 participants (actual)
- Lead sponsor
- James MerrillUniversity, hospital or other
- Collaborators
- Medtronic
- Study start
- Jan 2011
- Primary completion
- Aug 2012 (actual)
- Study completion
- Aug 2012 (actual)
- First posted
- 6 Jan 2014 (estimated)
- Results
- Posted 30 Dec 2014
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Nominal Parameter | Active comparator | Device: Nominal T shock settingNominal T shock setting |
| Experimental Parameter | Experimental | Device: Educated T shock settingEducated T shock setting |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- All patients undergoing Medtronic ICD or Cardiac Resynchronization Therapy-Defibrillator implant (initial implant or generator replacement) will be included.
Key exclusion criteria (1 listed)
- Any patient who is medically unstable and testing is deemed unsafe by physician will be excluded from this study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nominal T shock settingAlso: Medtronic ICDsNominal Parameter Set 1 Programming Values for EnTrust | Device | Nominal Parameter |
| Educated T shock settingAlso: Medtronic ICDsExperimental Parameter Set 2 Programming Values | Device | Experimental Parameter |
Primary outcome
Sustained Ventricular Fibrillation
Time frame: 2 hours
The primary endpoint is the successful induction of sustained ventricular fibrillation.
1 secondary outcome
Factors
Time frame: 2 hours
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 May 2018.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- BackgroundBardy 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.
- Background: PubMed 9533375Bhandari AK, Isber N, Estioko M, Ziccardi T, Cannom DS, Park Y, Lerman RD, Prejean C, Sun GW. Efficacy of low-energy T wave shocks for induction of ventricular fibrillation in patients with implantable cardioverter defibrillators. J Electrocardiol. 1998 Jan;31(1):31-7. doi: 10.1016/s0022-0736(98)90004-8.
- BackgroundMarquis DR Reference Manual, Medtronic, Inc.
- BackgroundMitchell 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.
- BackgroundSwartz 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nominal T shock setting and Educated T shock setting in people with Cardiomyopathy, run by James Merrill at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 May 2018. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 30 Dec 2014). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sustained Ventricular Fibrillation (time frame: 2 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02027883, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 May 2018; AzTrials last refreshed its copy on 31 Oct 2026.