Precise Measurement of Pediatric Defibrillation Thresholds

Boston Children's Hospital

Status: Completed

Conditions: Defibrillators, Implantable; Pediatrics

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

Study type: Observational

Funder types: Other

Identifiers

NCT01043562

09-04-0209

Details and patient eligibility

About

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.

Enrollment: 20 patients

Sex: All

Volunteers: No Healthy Volunteers

Inclusion criteria

• 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

Exclusion criteria

• 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

Trial design

20 participants in 1 patient group

Pediatric ICD pts

Description:

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).

Treatment:

Diagnostic Test: Defibrillator threshold testing

Other: Observation of post-shock intrinsic cardiac rhythm