Precise Measurement of Pediatric Defibrillation Thresholds

NCT01043562 | Completed Results

• 1 other identifier: 09-04-0209
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Patients who receive an implantable cardioverter-defibrillator (ICD) usually undergo testing at the end of the ICD procedure to measure the amount of energy able to successfully defibrillate the heart (defibrillation threshold testing, or DFT). This study proposes to perform that measurement in pediatric patients already undergoing clinically necessary ICD procedures, with the measurement performed using a binary search method that has been previously validated in adult cohorts. We hypothesize that pediatric DFTs, when precisely measured, may be lower than previously assumed from extrapolation of adult data.

Conditions

Pediatrics; Defibrillators, Implantable

Outcome Measures

Primary Outcomes (1)

• Defibrillation Threshold

  The defibrillation threshold is a measure of the minimum amount of energy (in Joules) that is able to successfully defibrillate an episode of ventricular fibrillation. This measurement is specific to each individual patient with his/her specific defibrillator configuration. There are several different strategies to measuring this in an individual patient; this study utilized the binary search protocol.

  During clinical ICD procedure, as a single event

Secondary Outcomes (2)

• Do DFTs Vary by Type of ICD Systems Implanted?

  During clinical ICD procedure, as a single event

• Intrinsic Heart Rate in the Immediate Post-defibrillation Period

  During clinical ICD procedure, as a single event

Study Arms (1)

Pediatric ICD pts

Inclusion criteria for study participants included: 1) weight ≤60 kg, 2) new or existing ICD system, and 3) clinically necessary assessment of the defibrillation efficacy of the ICD system. Transvenous systems utilized a high-voltage ICD coil with active-fixation lead attached to the right ventricular endocardial surface, whereas non-transvenous systems depended upon a high-voltage shocking coil placed within the pericardial, subcutaneous or pleural space. To be included in the post-shock pacing portion of the study, adequate sinus and AV node function had to be present at baseline. Exclusion criteria included 1) tenuous hemodynamic status felt to warrant abbreviation of the defibrillation efficacy testing or 2) inability to induce fibrillation during defibrillation threshold testing (DFT).

Diagnostic Test: Defibrillator threshold testing; Other: Observation of post-shock intrinsic cardiac rhythm

Interventions

Defibrillator threshold testing DIAGNOSTIC_TEST

Measurement of the defibrillation threshold was performed using a modified binary search protocol. This protocol specified three distinct inductions of ventricular fibrillation (VF) for all subjects, with a 3-5 minute observation/waiting period between inductions. The initial shock energy was programmed at 9 joules (J) for all patients, with internal rescue shocks at 31J followed by device-specific maximum deliverable energy. The outcome of the initial induction determined the programmed energies for both the initial and internal rescue shocks for the second induction, and likewise for the third induction. All shocks were biphasic and delivered at manufacturers' default tilt, polarity and duration, and all final programmed shock vectors included an active can. External defibrillation pads were in place for delivery of external rescue shock should the internal shocks fail.

Pediatric ICD pts

Observation of post-shock intrinsic cardiac rhythm OTHER

Prior to each of the three ventricular fibrillation inductions performed as part of the binary search protocol, post-shock pacing was re-programmed using a pre-determined, stepwise protocol that progressively decreased the lower rate limit. For the purpose of this protocol, post-shock pacing was considered necessary if 1) ≥7 ventricular-paced beats or 2) asystole \>4 seconds was observed in the first 20 seconds after defibrillation, or if the systolic blood pressure demonstrated a \>10% decrease from pre-induction baseline at follow-up measurement 1 minute post-defibrillation. Rescue ventricular pacing via the programmer was available for all subjects.

Pediatric ICD pts

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

All patients seen by the electrophysiology service at Children's Hospital Boston who are identified to be at very high risk of sudden cardiac death and in need of an ICD

You may qualify if:

• Current follow-up at Children's Hospital Boston
• Children with current or planned ICDs who are scheduled by their primary electrophysiologist for clinically necessary assessment/re-assessment of defibrillation threshold
• If the patient has an ICD system with a non-transvenous shock coil: weight ≤35kg at time of initial implant, with current weight \<50kg
• If the patient has an ICD system with a conventional transvenous shock coil: current weight ≤60kg

You may not qualify if:

• Clinical failure of any system component not able to be addressed by hardware repair or exchange
• Hemodynamic instability that in the judgment of the primary electrophysiologist warrants abbreviation of DFT assessment
• Unsuccessful induction of fibrillation during DFT testing

Sponsors & Collaborators

• Boston Children's Hospital: lead

Study Sites (1)

Children's Hospital Boston

Boston, Massachusetts, 02115, United States

Location

Results Point of Contact

• Title: Dr. Andrew E. Radbill
• Organization: Vanderbilt University (current institution)

andrew.radbill@vanderbilt.edu

615-322-7447

Study Officials

• Andrew E Radbill, MD

  Boston Children's Hospital

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor of Pediatrics

Study Record Dates

• First Submitted: January 6, 2010
• First Posted: January 7, 2010
• Study Start: June 4, 2009
• Primary Completion: May 26, 2010
• Study Completion: May 10, 2012
• Last Updated: February 5, 2018
• Results First Posted: February 5, 2018

Record last verified: 2017-07

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)