TY - JOUR
T1 - Minimal defibrillation thresholds and the correlation with implant position in subcutaneous implantable-defibrillator patients
AU - Quast, Anne-Floor B. E.
AU - Baalman, Sarah W. E.
AU - van der Stuijt, Willeke
AU - Wilde, Arthur A. M.
AU - Knops, Reinoud E.
PY - 2019/11
Y1 - 2019/11
N2 - Background: Since the introduction of the subcutaneous implantable-defibrillator (S-ICD) knowledge of factors elevating the defibrillation threshold (DFT), have increased. Optimal device positioning most likely results in a decrease in DFT. The PRAETORIAN score is a tool to systematically evaluate S-ICD implant position and predict conversion success by estimating the DFT on a chest X-ray. The objective of this study is to determine DFT in de novo S-ICD patients. Methods: De novo S-ICD patients were enrolled with DFT testing using a single 30 J shock or a prespecified step-down protocol. Chest X-rays were obtained and implant position was evaluated using the PRAETORIAN score. Results: Fifteen patients, age 47 (±18) years and body mass index (BMI) 25(±3) kg/m2, underwent conversion testing with a single 30 J shock. Fourteen patients (93%) converted successfully. Implant position was optimal in all patients, PRAETORIAN score of 30 (100%). Twelve patients were available for analysis in the step-down DFT cohort, age 46 years (±15), left ventricular ejection fraction 50% (±15%) and a median BMI of 25.7 kg/m2 (range 23.8-29.1 kg/m2). No complications occurred during DFT testing. Mean DFT was 29 J (±12 J). Time to shock was 11 seconds (±2 seconds) for a 20 J shock compared with 17 seconds in case of a 70 J shock output. Nearly all patients were implanted with optimal device positioning with the lowest possible PRAETORIAN score of 30 (92%). Conclusion: DFT in S-ICD patients with optimal device positioning is lower than previously reported. Conversion testing using a low shock output reduced time to therapy by 6 seconds on average.
AB - Background: Since the introduction of the subcutaneous implantable-defibrillator (S-ICD) knowledge of factors elevating the defibrillation threshold (DFT), have increased. Optimal device positioning most likely results in a decrease in DFT. The PRAETORIAN score is a tool to systematically evaluate S-ICD implant position and predict conversion success by estimating the DFT on a chest X-ray. The objective of this study is to determine DFT in de novo S-ICD patients. Methods: De novo S-ICD patients were enrolled with DFT testing using a single 30 J shock or a prespecified step-down protocol. Chest X-rays were obtained and implant position was evaluated using the PRAETORIAN score. Results: Fifteen patients, age 47 (±18) years and body mass index (BMI) 25(±3) kg/m2, underwent conversion testing with a single 30 J shock. Fourteen patients (93%) converted successfully. Implant position was optimal in all patients, PRAETORIAN score of 30 (100%). Twelve patients were available for analysis in the step-down DFT cohort, age 46 years (±15), left ventricular ejection fraction 50% (±15%) and a median BMI of 25.7 kg/m2 (range 23.8-29.1 kg/m2). No complications occurred during DFT testing. Mean DFT was 29 J (±12 J). Time to shock was 11 seconds (±2 seconds) for a 20 J shock compared with 17 seconds in case of a 70 J shock output. Nearly all patients were implanted with optimal device positioning with the lowest possible PRAETORIAN score of 30 (92%). Conclusion: DFT in S-ICD patients with optimal device positioning is lower than previously reported. Conversion testing using a low shock output reduced time to therapy by 6 seconds on average.
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85073953868&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/31512339
U2 - https://doi.org/10.1111/jce.14171
DO - https://doi.org/10.1111/jce.14171
M3 - Article
C2 - 31512339
SN - 1045-3873
VL - 30
SP - 2441
EP - 2447
JO - Journal of cardiovascular electrophysiology
JF - Journal of cardiovascular electrophysiology
IS - 11
ER -