Objectives:To evaluate the performance of AVEIR VR single chamber leadless pacemaker(AVEIR VR)in the real world in China and the predictive factors of pacing threshold to assess the feasibility of AVEIRTM VR implantation in the domestic population.Methods:All patients who underwent AVEIR VR implantation by experienced operators from Peking University People's Hospital in multiple domestic hospitals from June 2024 to October 2024 were consecutively included,and their baseline characteristics,procedural data(including pacemaker electrical measurements at various stages),and follow-up results were observed,recorded,and statistically analyzed.Results:This study included 20 patients who met the indication for pacemaker implantation and underwent AVEIR VR implantation.Their mean age was(71.40±13.37)years,body mass index(BMI)was(23.05±3.71)kg/m2,body surface area(BSA)was(1.70±0.16)m2,all 20 patients were successfully implanted with pacemakers,there were no major complications(newly occurred pericardial effusion during the perioperative period,cardiac tamponade,poor pacemaker function,pacemaker dislocation/perforation,tricuspid valve injury,myocardial infarction,stroke,pulmonary embolism,and clinical death).One patient developed new frequent ventricular premature contractions after pacemaker release.The pacing threshold(PCT)at one week after implantation was correlated with PCT in tether mode(r=0.650,P=0.009)and PCT in release phase(r=0.596,P=0.019),but not with the sensing and impedance in each phase.Conclusions:This preliminary exploration study show that AVEIRTM VR implantation demonstrates satisfactory performance among real world patients in China,especially in elderly and low weight populations,confirming its safety.

Objective:To evaluate the clinical feasibility of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation following transvenous lead extraction (TLE).Methods:This was a retrospective study. Consecutive patients who underwent S-ICD implantation at Peking University People′s Hospital between June 2015 and October 2023 were enrolled. Patients were divided into the TLE group and the newly implanted group based on whether they received TLE prior to S-ICD implantation. Baseline characteristics, S-ICD indication, defibrillation threshold test results, complications, and postoperative follow-up data were collected and compared between the two groups.Results:A total of 27 patients were included, aged (49.2±14.2) years, including 19 males. There were 12 patients in the TLE group and 15 in the newly implanted group. Compared with the TLE group, patients in the newly implanted group were younger ((43.3±13.7) years vs. (55.6±12.0) years, P=0.013). The main S-ICD indication in the TLE group was high infection risk (9/12), whereas in the newly implanted group it was younger age (11/15). All patients underwent successful S-ICD implantation, with 18 patients completing defibrillation threshold testing (all successful). Additionally, the TLE group had longer follow-up duration than the newly implanted group (42 (19, 60) months vs. 12 (3, 28) months, P=0.001). No complications or deaths occurred during follow-up, with normal device function in both groups. A total of 17 ventricular tachycardia or fibrillation events were recorded, of which 7 met defibrillation criteria and all received effective therapy. Conclusion:S-ICD demonstrates safety and efficacy as a therapeutic option for patients after TLE, with comparable device functionality and follow-up outcomes to patients with newly implanted S-ICD.

Objective:To evaluate the incidence and frequency of inappropriate shocks caused by defibrillation lead failure in patients with implantable cardioverter-defibrillators (ICD), and to explore methods for reducing the incidence and frequency of such inappropriate shocks.Methods:This was a single-center retrospective study involving patients treated for defibrillation lead failures at Peking University People′s Hospital between March 2015 and May 2024. Patients were divided into an alarm function group and a non-alarm function group based on whether their ICDs were equipped with lead alarm functions. Clinical data, lead data, and the incidence and frequency of inappropriate shocks were collected and compared between the two groups. A multivariate logistic regression model was used to analyze factors influencing the incidence and frequency of inappropriate ICD shocks. Kaplan-Meier survival curves were plotted to compare the trends in the incidence and frequency of inappropriate shocks over time since ICD implantation between the two groups.Results:A total of 59 patients were enrolled, with a age of (56.7±15.2) years, including 42 males (71%). The lifespan of the failed leads in the entire cohort was 64.0 (36.0, 96.0) months. There were 26 patients in the alarm function group and 33 in the non-alarm function group. The most common manifestations of lead failure were oversensing (85%, 50/59) and abnormal pacing impedance (42%, 25/59). A total of 33 patients (56%, 33/59) experienced inappropriate shock therapy, with an average of 27.3 shocks per patient. The frequency of inappropriate ICD shocks in the non-alarm function group was higher than that in the alarm function group (25.0 (10.0, 60.0) times/year vs. 5.0 (2.8, 7.8) times/year, P=0.001). Multivariate logistic regression analysis showed that oversensing ( OR=2.057, 95% CI 1.125-6.763, P=0.019) was an influencing factor for incidence of inappropriate shocks, while the lead alert function ( OR=0.062, 95% CI 0.005-0.719, P=0.001) was a factor influencing the frequency of inappropriate shocks. Kaplan-Meier survival analysis revealed that the incidence and frequency of inappropriate shocks increased with the duration of ICD implantation in both groups, but the differences were not statistically significant (incidence: log-rank P=0.908; frequency: log-rank P=0.767). Conclusion:The lead alert function can reduce the frequency of inappropriate shocks caused by lead failure.

Objectives:To analyze the clinical characteristics,strategies,success and complication rates of lead extraction and re-implantation during the upgrade of cardiovascular implantable electronic devices(CIED)in non-infectious patients.Methods:This retrospective study collected and analyzed the baseline clinical data and surgical data of 66 non-infected patients who had their existing CIEDs(including cardiac pacemaker,implantable cardioverter defibrillator[ICD],cardiac resynchronization therapy pacemaker[CRT-P])upgraded to ICD or CRT-P or cardiac resynchronization therapy defibrillator(CRT-D)or subcutaneous implantable cardioverter defibrillator(S-ICD)in Peking University People's Hospital from March 2018 to March 2024.We analyzed the strategies of lead extraction and reimplantation as well as the operation success rate and complication rate.Results:Among the 66 patients,preoperative imaging revealed that 12 patients(18.2%)had severe stenosis/occlusion of the venous access route,with lead wear/perforation in 26 patients(39.4%).32 patients(48.5%)underwent transvenous lead extraction(TLE),of which all leads were removed in 27 patients(84.4%),and only non-functional leads were removed in 5 patients(15.6%).The success rate of the TLE procedure was 100%and no complication occurred.Among the 66 patients,functional leads retained and new leads were implanted on the same side in 28 patients(42.4%),all leads were removed and new leads were reimplanted on the opposite side in 22 patients(33.3%),only non-functional leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),all leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),and 6 patients(9.1%)had the leads abandoned and then were re-implanled.The success rate of the upgrade surgery was 100%,no complications were reported.Conclusions:When the existing CIEDs(including cardiac pacemaker,ICD,CRT-P)of non-infected patients are upgraded to ICD,CRT-P,CRT-D or S-ICD,lead extraction and reimplantation are safe and feasible,and reimplantation can be performed on the ipsilateral or contralateral side.

Objectives:To evaluate the performance of AVEIR VR single chamber leadless pacemaker(AVEIR VR)in the real world in China and the predictive factors of pacing threshold to assess the feasibility of AVEIRTM VR implantation in the domestic population.Methods:All patients who underwent AVEIR VR implantation by experienced operators from Peking University People's Hospital in multiple domestic hospitals from June 2024 to October 2024 were consecutively included,and their baseline characteristics,procedural data(including pacemaker electrical measurements at various stages),and follow-up results were observed,recorded,and statistically analyzed.Results:This study included 20 patients who met the indication for pacemaker implantation and underwent AVEIR VR implantation.Their mean age was(71.40±13.37)years,body mass index(BMI)was(23.05±3.71)kg/m2,body surface area(BSA)was(1.70±0.16)m2,all 20 patients were successfully implanted with pacemakers,there were no major complications(newly occurred pericardial effusion during the perioperative period,cardiac tamponade,poor pacemaker function,pacemaker dislocation/perforation,tricuspid valve injury,myocardial infarction,stroke,pulmonary embolism,and clinical death).One patient developed new frequent ventricular premature contractions after pacemaker release.The pacing threshold(PCT)at one week after implantation was correlated with PCT in tether mode(r=0.650,P=0.009)and PCT in release phase(r=0.596,P=0.019),but not with the sensing and impedance in each phase.Conclusions:This preliminary exploration study show that AVEIRTM VR implantation demonstrates satisfactory performance among real world patients in China,especially in elderly and low weight populations,confirming its safety.

Objectives:To analyze the clinical characteristics,strategies,success and complication rates of lead extraction and re-implantation during the upgrade of cardiovascular implantable electronic devices(CIED)in non-infectious patients.Methods:This retrospective study collected and analyzed the baseline clinical data and surgical data of 66 non-infected patients who had their existing CIEDs(including cardiac pacemaker,implantable cardioverter defibrillator[ICD],cardiac resynchronization therapy pacemaker[CRT-P])upgraded to ICD or CRT-P or cardiac resynchronization therapy defibrillator(CRT-D)or subcutaneous implantable cardioverter defibrillator(S-ICD)in Peking University People's Hospital from March 2018 to March 2024.We analyzed the strategies of lead extraction and reimplantation as well as the operation success rate and complication rate.Results:Among the 66 patients,preoperative imaging revealed that 12 patients(18.2%)had severe stenosis/occlusion of the venous access route,with lead wear/perforation in 26 patients(39.4%).32 patients(48.5%)underwent transvenous lead extraction(TLE),of which all leads were removed in 27 patients(84.4%),and only non-functional leads were removed in 5 patients(15.6%).The success rate of the TLE procedure was 100%and no complication occurred.Among the 66 patients,functional leads retained and new leads were implanted on the same side in 28 patients(42.4%),all leads were removed and new leads were reimplanted on the opposite side in 22 patients(33.3%),only non-functional leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),all leads were removed and new leads were reimplanted on the same side in 5 patients(7.6%),and 6 patients(9.1%)had the leads abandoned and then were re-implanled.The success rate of the upgrade surgery was 100%,no complications were reported.Conclusions:When the existing CIEDs(including cardiac pacemaker,ICD,CRT-P)of non-infected patients are upgraded to ICD,CRT-P,CRT-D or S-ICD,lead extraction and reimplantation are safe and feasible,and reimplantation can be performed on the ipsilateral or contralateral side.

Objective:To evaluate the clinical feasibility of subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation following transvenous lead extraction (TLE).Methods:This was a retrospective study. Consecutive patients who underwent S-ICD implantation at Peking University People′s Hospital between June 2015 and October 2023 were enrolled. Patients were divided into the TLE group and the newly implanted group based on whether they received TLE prior to S-ICD implantation. Baseline characteristics, S-ICD indication, defibrillation threshold test results, complications, and postoperative follow-up data were collected and compared between the two groups.Results:A total of 27 patients were included, aged (49.2±14.2) years, including 19 males. There were 12 patients in the TLE group and 15 in the newly implanted group. Compared with the TLE group, patients in the newly implanted group were younger ((43.3±13.7) years vs. (55.6±12.0) years, P=0.013). The main S-ICD indication in the TLE group was high infection risk (9/12), whereas in the newly implanted group it was younger age (11/15). All patients underwent successful S-ICD implantation, with 18 patients completing defibrillation threshold testing (all successful). Additionally, the TLE group had longer follow-up duration than the newly implanted group (42 (19, 60) months vs. 12 (3, 28) months, P=0.001). No complications or deaths occurred during follow-up, with normal device function in both groups. A total of 17 ventricular tachycardia or fibrillation events were recorded, of which 7 met defibrillation criteria and all received effective therapy. Conclusion:S-ICD demonstrates safety and efficacy as a therapeutic option for patients after TLE, with comparable device functionality and follow-up outcomes to patients with newly implanted S-ICD.

Objective:To evaluate the incidence and frequency of inappropriate shocks caused by defibrillation lead failure in patients with implantable cardioverter-defibrillators (ICD), and to explore methods for reducing the incidence and frequency of such inappropriate shocks.Methods:This was a single-center retrospective study involving patients treated for defibrillation lead failures at Peking University People′s Hospital between March 2015 and May 2024. Patients were divided into an alarm function group and a non-alarm function group based on whether their ICDs were equipped with lead alarm functions. Clinical data, lead data, and the incidence and frequency of inappropriate shocks were collected and compared between the two groups. A multivariate logistic regression model was used to analyze factors influencing the incidence and frequency of inappropriate ICD shocks. Kaplan-Meier survival curves were plotted to compare the trends in the incidence and frequency of inappropriate shocks over time since ICD implantation between the two groups.Results:A total of 59 patients were enrolled, with a age of (56.7±15.2) years, including 42 males (71%). The lifespan of the failed leads in the entire cohort was 64.0 (36.0, 96.0) months. There were 26 patients in the alarm function group and 33 in the non-alarm function group. The most common manifestations of lead failure were oversensing (85%, 50/59) and abnormal pacing impedance (42%, 25/59). A total of 33 patients (56%, 33/59) experienced inappropriate shock therapy, with an average of 27.3 shocks per patient. The frequency of inappropriate ICD shocks in the non-alarm function group was higher than that in the alarm function group (25.0 (10.0, 60.0) times/year vs. 5.0 (2.8, 7.8) times/year, P=0.001). Multivariate logistic regression analysis showed that oversensing ( OR=2.057, 95% CI 1.125-6.763, P=0.019) was an influencing factor for incidence of inappropriate shocks, while the lead alert function ( OR=0.062, 95% CI 0.005-0.719, P=0.001) was a factor influencing the frequency of inappropriate shocks. Kaplan-Meier survival analysis revealed that the incidence and frequency of inappropriate shocks increased with the duration of ICD implantation in both groups, but the differences were not statistically significant (incidence: log-rank P=0.908; frequency: log-rank P=0.767). Conclusion:The lead alert function can reduce the frequency of inappropriate shocks caused by lead failure.

Objectives:To evaluate the safety and efficacy of implantation of subcutaneous implantable cardioverter defibrillator(S-ICD)after transvenous lead extraction(TLE)in ICD patients without pacing indications. Methods:All patients who underwent TLE at Peking University People's Hospital from June 2018 to October 2023 were consecutively included.TLE indication,S-ICD implantation indication,defibrillation threshold(DFT)test,complications and postoperative follow-up were collected and analyzed. Results:A total of 11 patients with TV-ICD underwent S-ICD implantation after TLE,eight patients were males and median age were 56(44,65)years.The indications for TLE were infection and lead dysfunction.Nine patients were implanted with S-ICD for secondary prevention,and the most common cause of implantation was ion channelopathies(5 cases).The operative time for S-ICD was 51(48,58)minutes and no perioperative complications were noted.Eight patients underwent DFT testing,and 100%were successful.During a median follow up of 30(9,39)months,a total of six appropriate treatments occurred in two patients,and no complications occurred,including inappropriate treatment,ineffective treatment,infection,lead malfunction and death. Conclusions:Our study provides evidence for S-ICD implantation as a replacement after TV-ICD removal.The S-ICD implantation after TLE is safe and effective.

Objectives:To evaluate the strategy and clinical outcomes of reimplanting biventricular cardiac resynchronization therapy (Biv-CRT) devices after transvenous removal of coronary sinus left ventricular leads due to device-related infections. Methods:A retrospective analysis was conducted on the clinical data and surgical outcomes of all patients who underwent transvenous removal of infectious coronary sinus left ventricular leads and subsequent reimplantation of Biv-CRT devices at Peking University People's Hospital from January 2013 to December 2022.Follow-up was performed to assess the incidence of complications and all-cause mortality. Results:A total of 167 patients underwent coronary sinus left ventricular lead removal due to infection,removal was successful in 161 cases (96.4％) and failed in 6 cases (3.6％).Among the patients with successful removal,109 cases (67.7％) were scheduled for Biv-CRT device reimplantation.After a median time of 7 (5,7) days,6 cases (5.5％) of reimplantation failed,while 103 reimplantations (94.5％) were successful.Among these successful reimplantation cases,102 patients (99.0％) were through the right-side approach,and 1 case (1.0％) through the left-side approach due to bilateral pocket infections.Of the 161 patients with successful removal,58 cases (36.0％) did not undergo left ventricular lead reimplantation,including 39 cases (24.2％) where the initial indications for Biv-CRT were questionable or had resolved.During the one-year postoperative follow-up,among the 103 patients who had undergone Biv-CRT device reimplantation,7 patients (6.8％) died,1 patient (1.0％) experienced pocket infection,and 1 patient (1.0％) had right atrial lead dislodgment. Conclusions:Reimplantation of Biv-CRT devices after removal of coronary sinus left ventricular leads due to infections is feasible,with a high success rate,low complication rate,and low mortality rate for right-side approach implantation.Therefore,for patients re-evaluated to have indications for repeated Biv-CRT after lead removal,right-side reimplantation of the coronary sinus left ventricular lead should be recommended.