An interventional study of Nominal T shock setting and Educated T shock setting in Cardiomyopathy, sponsored by James Merrill. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2018-05-22.
Sponsored by James Merrill · Not applicable, Interventional, and Treatment
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.
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.
1,176 studies on the registry are indexed under Cardiomyopathies; 287 are open to participants now.
This study's enrollment of 100 is above the median of 51 across 609 interventional studies indexed under Cardiomyopathies.
Browse Cardiomyopathies studies →This is the only study on the registry with James Merrill as lead sponsor.
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Exclusion Criteria:
Nominal T shock setting
Device: Nominal T shock setting
Educated T shock setting
Device: Educated T shock setting
Nominal Parameter Set 1 Programming Values for EnTrust
Also known as: Medtronic ICDs
Experimental Parameter Set 2 Programming Values
Also known as: Medtronic ICDs
Sustained Ventricular Fibrillation
The primary endpoint is the successful induction of sustained ventricular fibrillation.
Time frame: 2 hours
Factors
Determine if any pre-implant patient demographics are factors impacting T-shock success according to parameter settings.
Time frame: 2 hours
Safety Monitoring
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.
Time frame: 2 hours
| Milestone | Nominal Parameter | Experimental Parameter |
|---|---|---|
| Started | 50 | 50 |
| Completed | 50 | 50 |
| Not completed | 0 | 0 |
The primary endpoint is the successful induction of sustained ventricular fibrillation.
| participants | Nominal Parameter | Experimental Parameter |
|---|---|---|
| Sustained Ventricular Fibrillation | 38 | 35 |
Determine if any pre-implant patient demographics are factors impacting T-shock success according to parameter settings.
| participants | Nominal Parameter | Experimental Parameter |
|---|---|---|
| Successful Male Participants | 30 | 28 |
| Successful Female participants | 8 | 7 |
| Unsuccessful Male Participants | 8 | 12 |
| Unsuccessful Female Participants | 4 | 3 |
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.
| participants | Nominal Parameter | Experimental Parameter |
|---|---|---|
| Safety Monitoring | 50 | 50 |
Collected over The patient's were observed for adverse events from the time of consent to the time they met the primary endpoint.. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Nominal Parameter | — | 0/50 (0%) | 0/50 (0%) |
| Experimental Parameter | — | 0/50 (0%) | 0/50 (0%) |
| Age, Categorical(Participants) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 27 | 18 | 45 |
| >=65 years | 23 | 32 | 55 |
| Age, Continuous(years) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| Mean | 61.82 ± 13.68403 | 66.68 ± 10.51809 | 64.25 ± 12.38554 |
| Sex: Female, Male(Participants) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| Female | 12 | 10 | 22 |
| Male | 38 | 40 | 78 |
| Ethnicity (NIH/OMB)(Participants) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| Hispanic or Latino | 0 | 0 | 0 |
| Not Hispanic or Latino | 50 | 50 | 100 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 0 | 0 | 0 |
| White | 50 | 50 | 100 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Region of Enrollment(participants) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| United States | 50 | 50 | 100 |
| VF Induction amount of participants(participants) | Nominal Parameter | Experimental Parameter | Total |
|---|---|---|---|
| Number | 50 | 50 | 100 |
Plan to share: No
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