无导线起搏器置入术中阻抗对起搏阈值变化趋势预测价值初探

目的初步探讨无导线起搏器Micra置入术中释放即刻阻抗对起搏阈值变化趋势的预测价值。方法本研究为回顾性、横断面研究, 选取2019年12月—2020年8月在中南大学湘雅二医院接受无导线起搏器Micra置入的患者, 收集患者基本临床资料、无导线起搏器置入术中电学参数, 将阻抗和起搏阈值分为释放即刻、释放后5～10 min和牵拉试验后3组。采用重复测量方差分析统计对比3组电学参数, 绘制受试者工作特征(ROC)曲线并根据曲线下面积(AUC)分析释放即刻阻抗对起搏阈值变化趋势的预测价值。结果共纳入21例置入Micra无导线起搏器的患者, 男性12例(57%), 年龄(72.2±12.5)岁。21例患者置入术中释放即刻阻抗为(798.1±35.3)Ω, 释放后5～10 min为(800.9±35.6)Ω, 牵拉试验后为(883.6±31.7)Ω, 3组阻抗间的差异无统计学意义(P>0.05)。释放即刻阈值为(0.97±0.11)V/0.24 ms, 释放后5～10 min为(0.95±0.12)V/0.24 ms, 牵拉试验后为(0.59±0.06)V/0.24 ms, 牵拉试验后阈值低...

Predictive value of impedance of leadless pacemaker during implantation on trend changes of pacing threshold

Objective To explore the predictive value of the impedance measured during leadless pacemaker Micra implantation on the trend of changes of pacing threshold post implantation.Methods This is a retrospective cross-sectional study.Patients who received implantation of leadless pacemaker Micra at the Second Xiangya Hospital of Central South University from December 2019 to August 2020 were enrolled.The clinical data and the intraoperative electrical parameters during leadless pacemaker implantation were collected.The impedance and pacing threshold data were analyzed at three time points:immediate release,5-10 min after release,and after traction test.Receiver operating characteristic(ROC)curves and the area under the curve(AUC)were used to analyze the value of the impedance at immediate release on predicting the trend of changes of pacing threshold post implantation.Results A total of 21 patients(mean age:(72.2±12.5)years,12 males)were included.The impedance of 21 patients was(798.1±35.3)Ωimmediately after implantation,(800.9±35.6)Ωafter 5-10 minutes of release,and(883.6±31.7)Ωafter traction test.Impedance was similar between the three time points(P>0.05).The threshold was(0.97±0.11)V/0.24 ms immediately after implantation,(0.95±0.12)V/0.24 ms at 5-10 min after the release,and(0.59±0.06)V/0.24 ms after the traction test.The threshold was significantly lower after the traction test than that immediately after release(P=0.003)and than that at 5-10 minutes after release(P=0.008),suggesting a decreased tendency of the threshold over time.According to the analysis of the ROC curve,the immediate impedance after the release≥680Ωcould predict the ideal pacing threshold after the traction test(AUC=0.989,95%CI 0.702-0.964,P<0.001),the prediction sensitivity was 87%,and the specificity was 100%.The pacing threshold would be not ideal with the immediate impedance≤520Ω(95%CI 0.893-1.000,P<0.001),the sensitivity was 100%,and the specificity was 80%.Conclusions The impedance immediately after the release has predictive value for the changing trend of threshold post leadless pacemaker Micra implantation.Impedance≥680Ωimmediately after release is often related with ideal pacing threshold after the traction test.In contrast,the impedance≤520Ωpacing is often related with unsatisfactory threshold after the traction test,therefore,it is recommended to find a new pacing site to achieve the impedance≥680Ωimmediately after release during leadless pacemaker Micra implantation.