Abstract：
BACKGROUND: Guidelines recommend defibrillation testing (DFT) during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. Implant position, patient characteristics and device factors, such as shock impedance, influence defibrillation success. To evaluate the shock impedance, a manual synchronous 10J shock (low energy synchronous shock [LESS]) can be delivered, without the need to induce ventricular fibrillation (VF).
OBJECTIVE: To compare LESS and DFT impedance values and to evaluate the diagnostic accuracy of LESS impedance for predicting a successful DFT during S-ICD implantation.
METHODS: Consecutive S-ICD implantations were included. Shock impedances were compared by paired t-tests. Univariate analysis was performed to investigate factors associated with successful DFT. A prediction model of successful DFT based on LESS impedance was assessed by logistic regression. Receiver operating characteristic (ROC) curve, area under the ROC curve and the Hosmer-Lemeshow tests were used to evaluate the accuracy of LESS impedance.
RESULTS: Sixty patients were included (52 ± 14 years; 69% male). LESS and DFT impedance values were highly correlated (r2 = 0.97, p < .01). Patients with a failed first shock had higher body mass index (BMI) (30 ± 3 vs. 25.7 ± 4.3, p = .014), higher mean LESS (120 ± 35Ω vs. 86. ± 23Ω, p = .0013) and DFT impedance (122 ± 33Ω vs. 87 ± 24Ω, p = .0013). ROC analysis showed that LESS impedance had a good diagnostic performance in predicting a successful conversion test (AUC 84% [95% CI: 0.72-0.92]) with a cutoff value of <94Ω to identify a successful DFT (sensitivity 71%, specificity 73%).
CONCLUSIONS: LESS impedance values without the need to induce VF can intraoperatively predict a successful DFT.
OBJECTIVE: To compare LESS and DFT impedance values and to evaluate the diagnostic accuracy of LESS impedance for predicting a successful DFT during S-ICD implantation.
METHODS: Consecutive S-ICD implantations were included. Shock impedances were compared by paired t-tests. Univariate analysis was performed to investigate factors associated with successful DFT. A prediction model of successful DFT based on LESS impedance was assessed by logistic regression. Receiver operating characteristic (ROC) curve, area under the ROC curve and the Hosmer-Lemeshow tests were used to evaluate the accuracy of LESS impedance.
RESULTS: Sixty patients were included (52 ± 14 years; 69% male). LESS and DFT impedance values were highly correlated (r2 = 0.97, p < .01). Patients with a failed first shock had higher body mass index (BMI) (30 ± 3 vs. 25.7 ± 4.3, p = .014), higher mean LESS (120 ± 35Ω vs. 86. ± 23Ω, p = .0013) and DFT impedance (122 ± 33Ω vs. 87 ± 24Ω, p = .0013). ROC analysis showed that LESS impedance had a good diagnostic performance in predicting a successful conversion test (AUC 84% [95% CI: 0.72-0.92]) with a cutoff value of <94Ω to identify a successful DFT (sensitivity 71%, specificity 73%).
CONCLUSIONS: LESS impedance values without the need to induce VF can intraoperatively predict a successful DFT.
摘要：
背景：指南建议在皮下植入式心脏复律除颤器（S-ICD）植入过程中进行除颤测试（DFT）。植入位置,患者特征和设备因素，如冲击阻抗，影响除颤成功。要评估冲击阻抗，可以提供手动同步10J冲击（低能同步冲击[LESS]），无需诱发心室纤颤（VF）。
目的：比较LESS和DFT阻抗值，并评估LESS阻抗在S-ICD植入过程中预测成功DFT的诊断准确性。
方法：包括连续的S-ICD植入。通过配对t检验比较冲击阻抗。进行单因素分析以调查与成功DFT相关的因素。通过逻辑回归评估基于LESS阻抗的成功DFT预测模型。接收机工作特性(ROC)曲线,ROC曲线下面积和Hosmer-Lemeshow试验用于评估LESS阻抗的准确性。
结果：纳入60例患者（52±14岁；69%为男性）。LESS和DFT阻抗值高度相关(r2=0.97,p<0.01)。首次休克失败的患者体重指数（BMI）较高（30±3vs.25.7±4.3，p=.014），较高的平均值较低(120±35Ωvs.86.±23Ω,p=.0013)和DFT阻抗(122±33Ωvs.87±24Ω,p=.0013）。ROC分析表明，LESS阻抗在预测成功的转换测试（AUC84％[95％CI：0.72-0.92]）方面具有良好的诊断性能，其截止值<94Ω以识别成功的DFT（灵敏度71％，特异性73%)。
结论：不需要诱导VF的低阻抗值可以在术中预测成功的DFT。
目的：比较LESS和DFT阻抗值，并评估LESS阻抗在S-ICD植入过程中预测成功DFT的诊断准确性。
方法：包括连续的S-ICD植入。通过配对t检验比较冲击阻抗。进行单因素分析以调查与成功DFT相关的因素。通过逻辑回归评估基于LESS阻抗的成功DFT预测模型。接收机工作特性(ROC)曲线,ROC曲线下面积和Hosmer-Lemeshow试验用于评估LESS阻抗的准确性。
结果：纳入60例患者（52±14岁；69%为男性）。LESS和DFT阻抗值高度相关(r2=0.97,p<0.01)。首次休克失败的患者体重指数（BMI）较高（30±3vs.25.7±4.3，p=.014），较高的平均值较低(120±35Ωvs.86.±23Ω,p=.0013)和DFT阻抗(122±33Ωvs.87±24Ω,p=.0013）。ROC分析表明，LESS阻抗在预测成功的转换测试（AUC84％[95％CI：0.72-0.92]）方面具有良好的诊断性能，其截止值<94Ω以识别成功的DFT（灵敏度71％，特异性73%)。
结论：不需要诱导VF的低阻抗值可以在术中预测成功的DFT。
