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Leadless pacemakers have provided new treatment modalities that can be especially useful in patients with complex cardiac anatomy and contraindications toward other pacemaker approaches. The Aveir™ single-chamber (VR) leadless pacemaker (LP) (Abbott Laboratories, Chicago, IL) is a recently approved device that can be placed in the right ventricle for patients with bradycardia. In this case, we present a novel use for the device through placement in the atrium to control atrial flutter in a patient with a hypoplastic right ventricle.

An 87-year-old man developed delayed cardiac tamponade 55 min after leadless pacemaker implantation and recurrent pericardial effusion 20 days later. Electrocardiogram-gated enhanced cardiac computed tomography revealed that the leadless pacemaker tines on the lateral side had penetrated the right ventricular free wall. He underwent off-pump hemostatic surgery.

Leadless pacemaker implantation is recognized as safe and effective for treating bradycardia. However, there are limited descriptions of its use in patients with complex anatomical considerations. Here, we present a case detailing the successful implantation of a leadless pacemaker with a tortuous inferior vena cava and a narrow right atrium.

We present the case of an 82-year-old woman with history of bivalvular replacement (mitral mechanical prothesis and tricuspid bioprothesis) and subsequent tricuspid percutaneous valve-in-valve bioprothesis implantation. The patient developed an indication for pacemaker implantation. We describe the feasibility of leadless pacemaker implantation across the tricuspid prothesis when all other techniques fail.

Completely leadless cardiac resynchronization therapy is feasible with the combination of Micra AV pacemaker (Medtronic Inc) and WiSE-CRT (EBR Inc) systems. Several reports have highlighted this combination in Europe. This case report presents a 1- year follow-up the first reported concomitant use of the leadless systems in the United States. (Level of Difficulty: Advanced.)

Background: Fluoroscopy is the standard tool for transvenous implantation of traditional and leadless pacemakers (LPs). LPs are used to avoid complications of conventional pacemakers, but there still is a 6.5% risk of major complications. Mid–right ventricular (RV) septal device implantation is suggested to decrease the risk, but helpful cardiac landmarks cannot be visualized under fluoroscopy. Transesophageal echocardiography (TEE) is an alternative intraprocedural imaging method. Objective: The purpose of this study was to explore the spatial relationship of the LP to cardiac landmarks via TEE and their correlations with electrocardiographic (ECG) parameters, and to outline an intraprocedural method to confirm mid-RV nonapical lead positioning. Methods: Fifty-six patients undergoing implantation of LP with TEE guidance were enrolled in the study. Device position was evaluated by fluoroscopy, ECG, and TEE. Distances between the device and cardiac landmarks were measured by TEE and analyzed with ECG parameters with and without RV pacing. Results: Mid-RV septal positioning was achieved in all patients. TEE transgastric view (0°–40°/90°–130°) was the optimal view for visualizing device position. Mean tricuspid valve–LP distance was 4.9 ± 0.9 cm, mean pulmonary valve–LP distance was 4.2 ± 1 cm, and calculated RV apex–LP distance was 2.9 ± 1 cm. Mean LP paced QRS width was 160.8 ± 28 ms and increased from 117.2 ± 34 ms at baseline. LP RV pacing resulted in left bundle branch block pattern on ECG and 37.8% QRS widening by 43.5 ± 29 ms. Conclusion: TEE may guide LP implantation in the nonapical mid-RV position. Further studies are required to establish whether this technique reduces implant complications compared with conventional fluoroscopy.

31 years lady with complete atrioventricular canal defect, large primum atrial septal defect (ASD), inlet ventricular septal defect (VSD) and Eisenmenger syndrome, presented with atrial flutter and complete heart block. She was not suitable for corrective cardiac surgery and not yet indicated for heart-lung transplantation. She was advised single chamber permanent pacemaker and eventually Micra VR transcatheter leadless pacemaker was finalised for her. Transcatheter leadless pacemaker was deployed in her RV septum despite some unforeseen technical problems. This patient had intrahepatic interruption of IVC with Azygous continuation draining into SVC but this altered venovascular course was detected only fluoroscopically midway during the pacemaker implantation procedure and this was not detected in the preprocedural transthoracic echocardiography. This abnormal venous course was clearly demonstrated in the cardiac CT which was performed only after completion of the pacemaker implantation procedure in this patient. The technical challenges encountered mainly were mostly during the manipulation of the 27F delivery catheter of Micra through this altered cardiovascular anatomy via transfemoral approach and also due to the presence of septal defects. Thus, transcatheter leadless permanent pacemaker was implanted successfully through transfemoral access in this complex congenital heart disease with interrupted IVC and azygous continuation. Besides transthoracic echocardiography, it may be better to perform transesophageal echocardiography or even preferably radiological imaging like cardiac CT or MRI prior to transcatheter leadless pacemaker implantation in patients with complex congenital heart disease to understand the cardiovascular anatomy and plan the procedure.

Background: Leadless pacemakers have been designed as an alternative to transvenous systems which avoid some of the complications associated with transvenous devices. We aim to perform a systematic review of the literature to report the safety and efficacy findings of leadless pacemakers. Methods: We searched MEDLINE and EMBASE to identify studies reporting the safety, efficacy and outcomes of patients implanted with a leadless pacemaker. The pooled rate of adverse events was determined and random-effects meta-analysis was performed to compare rates of adverse outcomes for leadless compared to transvenous pacemakers. Results: A total of 18 studies were included with 2496 patients implanted with a leadless pacemaker and success rates range between 95.5 and 100%. The device or procedure related death rate was 0.3% while any complication and pericardial tamponade occurred in 3.1% and 1.4% of patients, respectively. Other complications such as pericardial effusion, device dislodgement, device revision, device malfunction, access site complications and infection occurred in less than 1% of patients. Meta-analysis of four studies suggests that there was no difference in hematoma (RR 0.67 95%CI 0.21–2.18, 3 studies), pericardial effusion (RR 0.59 95%CI 0.15–2.25, 3 studies), device dislocation (RR 0.33 95%CI 0.06–1.74, 3 studies), any complication (RR 0.44 95%CI 0.17–1.09, 4 studies) and death (RR 0.45 95%CI 0.15–1.35, 2 studies) comparing patients who received leadless and transvenous pacemakers. Conclusion: Leadless pacemakers are safe and effective for patients who have an indication for single chamber ventricular pacing and the findings appear to be comparable to transvenous pacemakers.

Background: Knowledge about impact of age and comorbidities on outcome in patients with leadless pacemakers (LPM) is limited., Objectives: To analyse outcome in LPM patients according to age and comorbidities., Methods: This Swiss, multi-centre, retrospective analysis includes all patients with LPM implanted between 2015 and 2022. Charlson-Comorbidity-Index (CCI) was determined and patients were divided into a low- (CCI ≤ 5) and high-comorbidity (CCI > 5) group. Peri-procedural complications, in-hospital death, and all-cause mortalities were assessed. Finally, all-cause mortality according to three groups (CCI ≤ 3, 4-5, >5) was compared to age and sex-adjusted mortality in the general Swiss population., Results: 863 patients (median age 81 years, 65% male, 42% with CCI > 5) were included. Peri-procedural/long-term complication rates did not differ between the low- vs. high-comorbidity groups (2.6% vs. 1.7%, p = 0.48 and 1.2% vs. 2.8%, p = 0.12, respectively). In-hospital (3.6% vs. 0.6%, p = 0.002) and all-cause mortality (HR 2.9, 95%CI 2.2-3.8, p < 0.001) were significantly higher in the high-comorbidity group resulting in a three-year mortality of 58% (95%CI 51-65%) vs. 22% (95%CI 17-27%) in the low-comorbidity group. In patients with a CCI ≤ 3, all-cause mortality was comparable to the age- and sex-adjusted mortality of the general Swiss population., Conclusions: In elderly patients with high comorbidity, LPM implantation was not associated with increased peri-procedural/long-term complications. All-cause mortality in LPM patients with a CCI ≤ 3 was comparable to age- and sex-adjusted mortality in the general Swiss population. Despite a relatively high three-year mortality due to competing risk factors, LPM implantation is safe, even in elderly patients with high comorbidity., Condensed Abstract: In this Swiss, multi-centre, retrospective cohort analysis, 863 patients implanted with a leadless pacemaker were included and divided into a high-comorbidity (with a CCI > 5) and low-comorbidity (with a CCI ≤ 5) group. There was no between group difference in terms of implantation outcomes and peri-operative or long-term complications. Furthermore, all-cause mortality during follow-up in patients with a CCI ≤ 3 was comparable to age- and sex-adjusted mortality in the general Swiss population. These data indicate that LPM implantation is a safe procedure, even in elderly patients with high comorbidity., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Aveir DR (Abbott, Abbott Park, IL) is a dual-chamber leadless pacemaker (LP) system with distinct atrial and ventricular LPs (ALP, VLP) that communicate wirelessly to deliver atrioventricular synchronous pacing. Success rates of these implant-to-implant (i2i) transmissions have not been systematically evaluated., Objective: This study aims to evaluate chronic i2i success rates in a clinical setting., Methods: Patients meeting standard dual-chamber pacing indications were enrolled and implanted with dual-chamber LP systems as part of a prospective international clinical trial (Aveir DR i2i Study). The percent of successful i2i transmissions from ALP-to-VLP (A-to-V) and VLP-to-ALP (V-to-A) were interrogated from LPs in de novo patients using the device programmer at implant, discharge, and at 1, 3, and 6 months postimplant (1M, 3M, 6M)., Results: A total of 399 patients completed device implant and i2i diagnostic interrogation (62% male; age 69 years; 65% sinus node dysfunction, 32% atrioventricular [AV] block). Median A-to-V and V-to-A i2i success rates exceeded 90% of beats at all time-points from implant to 6M. The minority of patients with A-to-V or V-to-A i2i success in <70% of beats at implant (A-to-V: 19% of patients, V-to-A: 31% of patients) showed roughly 40% improvement by 1M, with this minority dropping to roughly 5% of patients by 6M. Improvement in i2i communication success may be attributed to reprogramming of i2i setting levels, natural changes in dominant posture, and device stabilization., Conclusion: Wireless implant-to-implant communication in the new dual-chamber leadless pacemaker system demonstrated successful transmissions in >90% of beats throughout the 6-month evaluation period. Communication success improved significantly over time postimplant for specific subgroups., Clinical Trial Registration: Aveir DR i2i Study, ClinicalTrials.gov ID NCT05252702., Competing Interests: Disclosures Dr Doshihas has received consulting fees from Abbott and serves as a steering committee member for Abbott. Dr Ip has received consulting fees from Abbott and Medtronic, serves as a steering committee member of Abbott, and is a data safety monitoring committee member of Boston Scientific. Dr Defaye has received research grants from Abbott, Boston Scientific, and Medtronic. Dr Exner has received consulting fees and research grants from Abbott and Medtronic, and—unrelated to this manuscript—has received consulting fees and research grants from Boston Scientific and GE Healthcare as well equity in CorVista, Clarius, eMurmur, HelpWear, and ProtonIntel. Dr Reddy is a consultant to Abbott and—unrelated to this manuscript—he serves as a consultant, for and has equity in, Ablacon, Acutus Medical, Affera-Medtronic, Apama Medical-Boston Scientific, Anumana, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, CardioNXT/AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics-Medtronic, EpiEP, Eximo, Farapulse-Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Kardium, Keystone Heart, Laminar, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera-Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare; unrelated to this work, he has served as a consultant for AtriAN, Biosense Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, and Pulse Biosciences and has equity in DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. Dr Hindricks serves as a steering committee member for Abbott. Dr Canby has received consulting fees from Medtronic. Dr Shode serves as a steering committee member for Abbott. Dr Bongiorni serves as a steering committee member for Abbott. Dr Callahan has received consulting fees and honoraria from Abbott. Dr Badie and Dr Ligon are employees of Abbott and contributed to preparing and reviewing the manuscript for technical accuracy. Dr Knops has received research grants, consulting fees, and serves as a steering committee member of Abbott and Boston Scientific and has received speaking fees from Medtronic. The remaining author has no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Competing Interests: Disclosures The authors have no conflicts of interest to disclose.

Background: The first dual-chamber leadless pacemaker (DC-LP) system consists of 2 separate atrial and ventricular devices that communicate to maintain synchronous atrioventricular pacing and sensing. The initial safety and efficacy were previously reported., Objective: The purpose of this study was to evaluate the chronic electrical performance of the DC-LP system., Methods: Patients meeting standard dual-chamber pacing indications were enrolled and implanted with the DC-LP system (Aveir DR, Abbott), including right atrial and ventricular helix-fixation LPs (atrial leadless pacemaker [ALP], ventricular leadless pacemaker [VLP]). Pacing capture threshold, sensed amplitude, and pacing impedance were collected using the device programmer at prespecified timepoints from 0-6 months postimplant., Results: De novo devices were successfully implanted in 381 patients with complete 6-month data (62% male; age 69 ± 14 years; weight 82 ± 20 kg; 65% sinus nodal dysfunction, 30% atrioventricular block). ALPs were implanted predominantly in the right atrial appendage anterior base and VLPs primarily at the mid-to-apical right ventricular septum. From implant to 1 month, pacing capture thresholds (0.4-ms pulse width) improved in both ALPs (2.4 ± 1.5 V to 0.8 ± 0.8 V; P <.001) and VLPs (0.8 ± 0.6 V to 0.6 ± 0.4 V; P <.001). Sensed amplitudes improved in both ALPs (1.8 ± 1.3 mV to 3.4 ± 1.9 mV; P <.001) and VLPs (8.8 ± 4.0 mV to 11.7 ± 4.2 mV; P <.001). Impedances were stable in ALPs (334 ± 68 Ω to 329 ± 52 Ω; P = .17) and reduced in VLPs (789 ± 351 Ω to 646 ± 190 Ω; P <.001). Electrical measurements remained relatively stable from 1-6 months postimplant. No differences in electrical metrics were observed among ALP or VLP implant locations., Conclusion: This first in-human evaluation of the new dual-chamber leadless pacemaker system demonstrated reliable electrical performance throughout the initial 6-month evaluation period., Competing Interests: Disclosures Dr Rahul Doshi, Dr Derek V. Exner, Dr Vivek Y. Reddy, Dr Reinoud E. Knops, Dr Petr Neužil, Dr Thomas Callahan, Dr Sri Sundaram, and Dr James E. Ip report Abbott consulting fees. Dr Pascal Defaye, Dr Derek V. Exner, and Dr Reinoud E. Knops report Abbott research grants. Dr Derek V. Exner, Dr Thomas Callahan, and Dr Sri Sundaram report Abbott honoraria. Dr Gerhard Hindricks, Dr Rahul Doshi, Dr Reinoud E. Knops, Dr Morio Shoda, Dr Maria Grazia Bongiorni, and Dr James E. Ip serve as Abbott steering committee members. Dr Nima Badie is an Abbott employee. Additional Disclosures unrelated to this manuscript: Dr Petr Neužil reports research grants from Boston Scientific and Medtronic. Dr Derek V. Exner serves as a consultant for Boston Scientific, Medtronic, and GE Healthcare; and has equity in Clarius, CorVista eMurmur, HelpWear, and ProtonIntel. Dr Vivek Y. Reddy serves as a consultant for and has equity in Ablacon, Acutus Medical, Affera-Medtronic, Apama Medical-Boston Scientific, Anumana, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, CardioNXT/AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics-Medtronic, EpiEP, Eximo, Farapulse-Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Kardium, Keystone Heart, Laminar Medical, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera-Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare. Dr Vivek Y. Reddy has served as a consultant for Adagio Medical, AtriAN, Biosense-Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, Pulse Biosciences; and has equity in DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. Dr Reinoud E. Knops reports research grants, consulting fees, and serves as a steering committee member of Boston Scientific; and reports speaking fees from Medtronic. Dr Robert Canby reports consulting fees from Medtronic. Dr Thomas Callahan reports speaking and consulting feeds from Medtronic, Philips, Boston Scientific, and ShockWave. Dr Sri Sundaram holds an unrelated patent with Abbott. Dr James E. Ip reports consulting fees from Medtronic and serves as a data safety monitoring committee member of Boston Scientific. All other authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Rapid technologic development and expansion of procedural expertise have led to widespread proliferation of catheter-based electrophysiology procedures. It is unclear whether these advances come at cost to patient safety., Objective: This meta-analysis aimed to assess complication rates after modern electrophysiology procedures during the lifetime of the procedures., Methods: A comprehensive search was performed to identify relevant data published before May 30, 2023. Studies were included if they met the following inclusion criteria: prospective trials or registries, including comprehensive complications data; and patients undergoing atrial fibrillation ablation, ventricular tachyarrhythmia ablation, leadless cardiac pacemaker implantation, and percutaneous left atrial appendage occlusion. Pooled incidences of procedure-related complications were individually assessed by random effects models to account for heterogeneity. Temporal trends in complications were investigated by clustering trials by publication year (2000-2018 vs 2019-2023)., Results: A total of 174 studies (43,914 patients) met criteria for analysis: 126 studies of atrial fibrillation ablation (n = 24,057), 25 studies of ventricular tachyarrhythmia ablation (n = 1781), 21 studies of leadless cardiac pacemaker (n = 8896), and 18 studies of left atrial appendage occlusion (n = 9180). The pooled incidences of serious procedure-related complications (3.49% [2000-2018] vs 3.05% [2019-2023]; P < .001), procedure-related stroke (0.46% vs 0.28%; P = .002), pericardial effusion requiring intervention (1.02% vs 0.83%; P = .037), and procedure-related death (0.15% vs 0.06%; P = .003) significantly decreased over time. However, there was no significant difference in the incidence of vascular complications over time (1.86% vs 1.88%; P = .888)., Conclusion: Despite an increase in cardiac electrophysiology procedures, procedural safety has improved over time., Competing Interests: Disclosures Dr Reddy reports no disclosures related to this manuscript; but unrelated to this manuscript, he serves as a consultant for and has equity in Ablacon, Acutus Medical, Affera-Medtronic, Apama Medical–Boston Scientific, Anumana, APN Health, Aquaheart, Atacor, Autonomix, Axon Therapies, Backbeat, BioSig, CardiaCare, CardioNXT/AFTx, Circa Scientific, CoRISMA, Corvia Medical, Dinova-Hangzhou DiNovA EP Technology, East End Medical, EPD-Philips, EP Frontiers, Epix Therapeutics–Medtronic, EpiEP, Eximo, Farapulse–Boston Scientific, Field Medical, Focused Therapeutics, HRT, Intershunt, Javelin, Kardium, Keystone Heart, Laminar Medical, LuxMed, Medlumics, Middlepeak, Neutrace, Nuvera–Biosense Webster, Oracle Health, Restore Medical, Sirona Medical, SoundCath, Valcare; unrelated to this work, has served as a consultant for Abbott, Adagio Medical, AtriAN, Biosense-Webster, BioTel Heart, Biotronik, Boston Scientific, Cairdac, Cardiofocus, Cardionomic, CoreMap, Fire1, Gore & Associates, Impulse Dynamics, Medtronic, Novartis, Philips, Pulse Biosciences; and has equity in DRS Vascular, Manual Surgical Sciences, Newpace, Nyra Medical, Surecor, and Vizaramed. Dr Koruth has received grant support and stock options from Affera-Medtronic; unrelated to this manuscript, he has also served as a consultant to and has received grant support from Cardiofocus; has served as a consultant for Abbott, Boston Scientific, Biosense Webster, and Medtronic; and has received grant support from Pulse Bioscience. All other authors report no conflicts., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Leadless pacemakers have emerged as a promising alternative to transvenous pacemakers in patients with kidney disease. However, studies investigating leadless pacemaker outcomes and complications based on kidney dysfunction are limited., Objective: The objective of this study was to evaluate the association of chronic kidney disease (CKD) and end-stage renal disease (ESRD) with inpatient complications and outcomes of leadless pacemaker implantations., Methods: National Inpatient Sample and International Classification of Diseases, Tenth Revision codes were used to identify patients with CKD and ESRD who underwent leadless pacemaker implantations in the United States from 2016 to 2020. Study end points assessed included inpatient complications, outcomes, and resource utilization of leadless pacemaker implantations., Results: A total of 29,005 leadless pacemaker placements were identified. Patients with CKD (n = 5245 [18.1%]) and ESRD (n = 3790 [13.1%]) were younger than patients without CKD and had higher prevalence of important comorbidities. In crude analysis, ESRD was associated with higher prevalence of major complications, peripheral vascular complications, and inpatient mortality. After multivariable adjustment, CKD and ESRD were associated with inpatient mortality (CKD: adjusted odds ratio [aOR], 1.62 [95% CI, 1.40-1.86]; ESRD: aOR, 1.38 [95% CI, 1.18-1.63]) and prolonged length of stay (CKD: aOR, 1.55 [95% CI, 1.46-1.66]; ESRD: aOR, 1.81 [95% CI 1.67-1.96]). ESRD was also associated with higher hospitalization costs (aOR, 1.63; 95% CI, 1.50-1.77) and major complications (aOR, 1.33; 95% CI, 1.13-1.57) after leadless pacemaker implantation., Conclusion: Approximately one-third of patients undergoing leadless pacemaker implantation had CKD or ESRD. CKD and ESRD were associated with greater length and cost of stay and inpatient mortality., Competing Interests: Disclosures The authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The leadless pacemaking transcatheter system, Micra, is a miniaturized, single-chamber pacemaker system. We report herein our experience with implantation of the Micra TPS system. Objective: The current study was conducted to evaluate the safety and efficacy of the leadless Micra Transcatheter Pacemaker System (Medtronic). Research design and methods: This was a prospective single centre nonrandomized study without controls. A transcatheter pacemaker was implanted in patients who had guideline based indications for ventricular pacing. 28 subjects were screened based on the selection criteria. Mica TPS was implanted. Parameters assessed were: duration of procedure (from femoral vein puncture to venous access closure), fluoroscopy time, number of device repositions, periprocedural electrical measurements (sensing, threshold and impedance) and in-hospital, intermediate to long term adverse events related to procedure. Result and conclusion: s: The device was successfully implanted in 28 subjects. The mean intraoperative sensing value was 9.04 ± 1.5 mV and the impedance was 766.89 ± 213.9 Ω. At discharge from hospital, those values were 13.2 ± 15.83 mV and 855 ± 111.7, respectively. The recommended pacing threshold value as achieved in all subjects was 0.78 V, i.e. ≤ 1 V at 0.24 ms. There was no adverse event or complications reported for any of the subjects. Mean time from hospitalization to discharge was 1.5 days. Implantation of leadless pacemakers is feasible, safe and provides advantages over the conventional system.

Background: In this study we report our experience in implanting MICRA TPS (transcatheter pacing system) at various RV sites; observing its safety, and impact on paced QRS in Indian population. Material & methods: 35 patients with MICRA TPS deployed from March 2017 to December 2019 at Army Hospital Research and Referral, New Delhi, at RVOT, apical septum and mid septum of RV were enrolled in the study. These patents were followed up and impact of implantation site, procedure related complications, change in pacing parameters, left ventricular ejection fraction and duration of paced QRS were monitored. Results: Sick sinus syndrome was the commonest indication of pacing in this study (51.5%), followed by high degree AV block (34.2%). Mean follow up of 1.4 years showed no change in left ventricular ejection fraction, electrical parameters or change in pacing thresholds after implantation. Mean pQRS was broadest (166.60 ms) in apically implanted MICRA TPS and narrowest in mid septum group 139.33 ms. Among 35 cases, in our study one patient developed pericardial effusion, and other had intermittent diaphragmatic pacing. Conclusion: Among these three implantation sites mid septum deployment is associated with narrowest paced QRS in Indian population.

Objectives: Comparison of outcomes, device deployment time (DT), and total time (TT) using a single tapered Coons dilator versus sequential serial dilation for implantation of the Micra leadless pacemaker. Background: Micra leadless pacemaker placement requires a 23 French Micra introducer sheath (MIS) for percutaneous delivery. We sought to evaluate outcomes with use of a single tapered Coons dilator (CD) versus sequential serial dilatation (SD) method to facilitate insertion of the Micra introducer sheath. Methods: 35 patients were included in the SD arm and 49 in the CD arm. DT and TT were recorded in minutes and cost in dollars. Analysis was performed using independent t-test between two groups and one-way ANOVA to evaluate inter-operator variability in the CD arm. Results: Both DT and TT were significantly lower for the CD arm (15.1 ± 5.1 vs 23.5 ± 9.3, p

Competing Interests: Disclosures The authors have no conflicts of interest to disclose.

Background: Evidence is limited regarding the effectiveness of leadless pacemaker implantation for conduction disturbance following transcatheter aortic valve replacement (TAVR)., Objectives: This study sought to examine the national trends in the use of leadless pacemaker implantation following TAVR and compare its performance with transvenous pacemakers., Methods: Medicare fee-for-service beneficiaries aged ≥65 years who underwent leadless or transvenous pacemakers following TAVR between 2017 and 2020 were included. Outcomes included in-hospital overall complications as well as midterm (up to 2 years) all-cause death, heart failure hospitalization, infective endocarditis, and device-related complications. Propensity score overlap weighting analysis was used., Results: A total of 10,338 patients (730 leadless vs 9,608 transvenous) were included. Between 2017 and 2020, there was a 3.5-fold increase in the proportion of leadless pacemakers implanted following TAVR. Leadless pacemaker recipients had more comorbidities, including atrial fibrillation and end-stage renal disease. After adjusting for potential confounders, patients with leadless pacemakers experienced a lower rate of in-hospital overall complications compared with patients who received transvenous pacemakers (7.2% vs 10.1%; P = 0.014). In the midterm, we found no significant differences in all-cause death (adjusted HR: 1.13; 95% CI: 0.96-1.32; P = 0.15), heart failure hospitalization (subdistribution HR: 0.89; 95% CI: 0.74-1.08; P = 0.24), or infective endocarditis (subdistribution HR: 0.98; 95% CI: 0.44-2.17; P = 0.95) between the 2 groups, but leadless pacemakers were associated with a lower risk of device-related complications (subdistribution HR: 0.37; 95% CI: 0.21-0.64; P < 0.001)., Conclusions: Leadless pacemakers are increasingly being used for conduction disturbance following TAVR and were associated with a lower rate of in-hospital complications and midterm device-related complications compared to transvenous pacemakers without a difference in midterm mortality., Competing Interests: Funding Support and Author Disclosures Dr Kolte has received research funding from the National Institutes of Health/National Heart, Lung, and Blood Institute outside the submitted work. Dr Latib is a consultant and serves on the Advisory Board of Medtronic, Abbott, Boston Scientific, and Philips. Dr Tsugawa has received grants from the National Institutes of Health/National Institute on Aging (grants R01AG068633 and R01AG082991), National Institutes of Health/National Institute on Minority Health and Health Disparities (grant R01MD013913), and GRoW @Annenberg outside the submitted work; and serves on the board of directors for M3 Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Limited data are available on leadless pacemaker (LPM) outcomes according to different stages of chronic kidney disease (CKD)., Objective: The purpose of this study was to investigate differences in the safety and efficacy of LPMs among patients stratified per different stages of renal function., Methods: Consecutive patients enrolled in the multicenter international i-LEAPER registry (International LEAdless PacemakEr Registry) were analyzed. Patients were divided into 3 groups according to CKD stage. The primary end point was the comparison of LPM-related major complication rate at implantation and during follow-up. Differences in electrical performance were deemed secondary outcomes., Results: Of the 1748 patients enrolled, 33% were in CKD stage G3a/G3b and 9.4% were in CKD stage G4/G5. Patients with CKD presented cardiovascular comorbidities more frequently. During a median follow-up of 39 months (interquartile range [IQR] 18-59 months), major complication rate did not differ between groups (normal kidney function [NKF] group 1.8% vs CKD stage G3a/G3b group 2.9% vs CKD stage G4/G5 group 2.4%; P = .418). All-cause mortality resulted higher in the CKD stage G4/G5 group than in the NKF group (19.5% vs 9.8%; adjusted hazard ratio 1.9; 95% confidence interval 1.25-2.89; P = .003). LPM electrical performance was comparable between groups, except for patients with CKD who showed a slightly higher pacing threshold during 1-month follow-up (NKF group 0.50 V [IQR 0.35-0.70 V] vs G3a/G3b group 0.56 V [IQR 0.38-0.81 V] vs G4/G5 group 0.51 V [0.38-0.84 V] @ 0.24 ms; P < .001)., Conclusion: In a real-world setting, patients with advanced CKD who underwent LPM implantation were underrepresented. Although all-cause mortality was higher in end-stage CKD, periprocedural complications and LPM performance were overall comparable between NKF and different stages of CKD, except for higher values of pacing threshold in patients with CKD up to first-month follow-up., Competing Interests: Disclosures Dr Tondo is a member of an advisory board of Medtronic. Other authors do not report disclosures regarding this article., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Leadless pacemakers (LPs) capable of VDD pacing allow for atrioventricular synchrony through mechanical sensing of atrial contraction. However, mechanical sensing is less reliable and less predictable than electrical sensing., Objective: The purpose of this study was to evaluate P-wave amplitude during sinus rhythm from preoperative 12-lead electrocardiograms (ECGs) as a predictor for atrial mechanical sensing in patients undergoing VDD LP implantation., Methods: Consecutive patients undergoing VDD LP implantation were included in this 2-center prospective cohort study. ECG parameters were evaluated separately and in combination for association with the signal amplitude of atrial mechanical contraction (A4)., Results: Eighty patients (median age 82 years; female 55%; mean body mass index [BMI] 25.8 kg/m 2 ) were included in the study and 61 patients in the A4 signal analysis (19 patients in VVI mode during follow-up). Absolute (aVL, aVF, V 1 , V 2 ) and BMI-adjusted (I, II, aVL, aVF, aVR, V 1 , V 2 ) P-wave amplitudes from baseline ECGs demonstrated a statistically significant positive correlation with A4 signal amplitude (all P <.05). A combined P-wave signal amplitude of at least 0.2 mV in V 1 and aVL was predictive, with specificity of 83% (95% confidence interval 67%-100%) for A4 signal ≥1 m/s 2 . We found a significant correlation of A4 signal amplitude and overall atrioventricular synchrony (P = .013)., Conclusion: P-wave amplitudes in ECG leads aVL and V 1 can predict A4 signal amplitude in patients with VDD LP and therefore the probability of successful AV synchronous pacing., Competing Interests: Disclosures Dr Hofer reports educational grants, consultant or speaker fees, and fellowship support from Abbott, Medtronic, Biotronik, Boston Scientific, Biosense Webster, Novartis, Bayer, Pfizer, and Spectranetics. Dr Breitenstein has received consultant and/or speaker fees from Abbott, Bayer Healthcare, Biosense Webster, Biotronik, Boston Scientific, Bristol-Myers Squibb, Cook Medical, Daiichi Sankyo, Medtronic, Pfizer, and Spectranetics/Philipps. Dr Steffel has received consultant and/or speaker fees from Abbott, Alexion, Astra-Zeneca, Bayer, Berlin-Chemie, Biosense Webster, Biotronik, Boehringer-Ingelheim, Boston Scientific, BMS, Daiichi Sankyo, Medscape, Medtronic, Menarini, Merck/MSD, Organon, Pfizer, Saja, Servier, and WebMD; and reports ownership of Swiss EP and CorXL. Dr Haeberlin has received travel fees/educational grants from Medtronic, Biotronik, Abbott, and Philips/Spectranetics without impact on his personal remuneration; serves as a proctor for Medtronic; has received research grants from the Swiss National Science Foundation, Swiss Innovation agency Innosuisse, Swiss Heart Foundation, University of Bern, University Hospital Bern, Velux Foundation, Hasler Foundation, Swiss Heart Rhythm Foundation, and Novartis Research Foundation; and is co-founder and CEO of Act-Inno AG. Dr Steinwender has received consultant and/or speaker fees from Medtronic, Biotronik, Abbott, Boston Scientific, and Microport; and serves as a proctor for Medtronic. Dr Saguner received educational grants through his institution from Abbott, Bayer Healthcare, Biosense Webster, Biotronik, Boston Scientific, BMS/Pfizer, and Medtronic; and speaker/advisory board/consulting fees from Bayer Healthcare, Biotronik, Daiichi-Sankyo, Medtronic, Novartis, Pfizer, Stride Bio Inc, and Zoll. He has stock options from Gilead Sciences. Dr El-Chami is a consultant for Medtronic and Boston Scientific. All other authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Based on historical studies of leadless pacemakers (LPs), high atrioventricular synchrony (AVS) with mechanical sensing-based VDD pacing is largely influenced by A4 amplitude. A limited study investigated the predictors of A4 amplitude using clinical and echocardiographic parameters., Objective: The purpose of this study was to investigate the predictors of A4 amplitude preoperatively to select patients who could benefit the most from AVS among patients with VDD LPs (Micra-AV, Medtronic)., Methods: Data from patients who received Micra-AV implantations from November 2021 to August 2023 at Tottori University Hospital were analyzed. Twelve-lead electrocardiography and transthoracic echocardiography were performed before the Micra-AV implantations. To assess the electrical indices associated with the A4 signal, electrocardiographic morphologic P-wave parameters were analyzed, including P-wave duration, P-wave amplitude, maximum deflection index (MDI), and P-wave dispersion., Results: A total of 50 patients who underwent Micra-AV implantations (median age 84 years; 64% male) were included and divided into 2 groups based on the median value of A4 amplitude, the high-A4 group (A4 amplitude >2.5 m/s 2 ; n = 26), and low-A4 group (A4 amplitude ≤2.5 m/s 2 ; n = 24). There was a significant difference between the high-A4 and low-A4 groups with regard to left ventricular ejection fraction (P = .01), P-wave dispersion (P = .01), and MDI (P <.001). Multivariate logistic analysis revealed that lower MDI was an independent predictor of high A4-amplitude (odds ratio 0.78; 95% confidence interval 0.67-0.92; P = 0.003)., Conclusion: Preoperative electrocardiographic evaluations of P-wave morphology may be useful for predicting A4 amplitude. MDI was the only independent A4 amplitude predictor that seemed promising for selecting Micra-AV patients., Competing Interests: Disclosures This research was supported by the External Research Program (Grant Number ERP-2022-13342) from Medtronic Japan Co., Ltd. Dr Yamamoto has received lecturer fees from Otsuka Pharmaceutical Co., Ltd., Daiichi-Sankyo Co., Ltd., and Novartis; and research grants from Abbott, Otsuka Pharmaceutical Co., Ltd., Medtronic Japan Co., Ltd., Daiichi-Sankyo Co., Ltd., Boston Scientific Co., Ltd., Biotronik Japan Inc., Japan Lifeline Co., Ltd., Mitsubishi Tanabe Pharma Co., Ltd., Fukuda Denshi, Takeda Pharmaceutical Co., Ltd., Ono Pharmaceutical Co., Ltd., and Novartis. Dr Kato has received research grants from Medtronic Japan Co., Ltd (Grant Number ERP-2022-13342). Dr Okamura has received lecturer fees from Medtronic Japan Co., Ltd. All other authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Competing Interests: Disclosures Dr Di Biase is a consultant for Biosense Webster, Boston Scientific, Stereotaxis, and St. Jude Medical; and has received speaker honoraria from Medtronic, AtriCure, EPiEP, and Biotronik. Dr Natale is a consultant for Biosense Webster, Stereotaxis, and Abbott Medical; and has received speaker honoraria/travel from Medtronic, AtriCure, Biotronik, and Janssen. All other authors have no conflicts of interest to disclose.

Background: Transcatheter aortic valve replacement (TAVR) has evolved as a breakthrough therapy for patients with severe aortic valve stenosis. While TAVR has revolutionized the management of aortic valve disease, the procedure may be associated with the development of conduction disturbances requiring permanent pacemaker implantation. Traditionally, conventional transvenous pacemakers have been used to address these complications. However, the introduction of leadless pacemaker technology, such as the MICRA Transcatheter Pacing System (TPS), offers a novel alternative., Materials and Methods: This was a retrospective single-center study where all patients who underwent TAVR at our center and subsequently required permanent pacemaker implantation within 30 days were reviewed. We included only the patients who underwent leadless pacemaker placement. We then conducted a retrospective chart review to identify patient and procedural characteristics, procedural details, and relevant clinical outcomes., Results: A total of 9 patients were identified. All of the patients underwent MICRA AV placement within 30 days post-TAVR by an interventional cardiologist. The average age of the cohort was 79.6 years with an average STS score of 3.7 %. The majority of the patients received balloon-expandable valves (78 %). There were no procedural complications in any of the patients. At an average follow-up of 353 days, capture thresholds and lead impedance remained stable with an average RV pacing of 13 %., Conclusion: This small, retrospective cohort demonstrates that the use of MICRA AV leadless pacemakers is feasible after TAVR and is associated with low periprocedural complications. Leadless pacemakers provide stable pacing thresholds and AV synchrony., Competing Interests: Declaration of competing interest None of the authors have any conflict of Interest to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A nine year old girl weighing only 24 kg with complete heart block after surgical closure of perimembranous ventricular septal defect presented with recurrent pacemaker infection. As she was too small for the conventional femoral approach, leadless pacemaker (Micra, Medtronic) was implanted by an external iliac venous cut down. Device was implanted successfully and patient is doing well on follow up.

A 92-year-old woman underwent an implantation of a leadless pacemaker (Micra; Medtronic, Inc, Minneapolis, MN) for complete atrioventricular block after a transvenous lead extraction due to a pocket infection of a dual chamber pacemaker. Marked scoliosis and a humpback due to an advanced age made it impossible to direct the tip of the pacemaker delivery catheter towards the right ventricular septum or apex and shape the catheter into a gooseneck-shape. Thus, by attaining a halo-catheter shape of the delivery catheter, the catheter tip could be directed toward the infero-basal portion of the right ventricular septum. The pacemaker was successfully deployed at that site without any complications, and good device parameters were achieved. The halo-shape technique may be also an alternative method for delivering a leadless pacemaker in patients with an unsuccessful delivery of a leadless pacemaker to the right ventricular septum using the conventional gooseneck-shape technique.

Vasovagal syncope is characterized by vasodilatation and/or bradycardia and thereby a fall in arterial BP and global cerebral perfusion in response to a trigger. Although it is a benign condition, patients with frequent and traumatic episodes need treatment in order to improve quality of life. We describe the case of a 17-years-old boy suffering from cardioinhibitory syncope. At the end of a complete negative cardiac and neurological examination, a loop recorder was implanted. During the subsequent follow-up the ILR documented a 9-s pause. To improve the patient's compliance, and considering cardioinhibitory syncope as a temporary condition, a leadless pacemaker was eventually implanted.

We report a case of a 85-year old woman with a preexisting Transcatheter Pacing System (TPS) (Micra™ VR, Fa. Medtronic, Inc., Minneapolis, MN, USA) undergoing several external electrical cardioversions (CV) for symptomatic persistent atrial fibrillation (persAF). Due to bradycardia in the setting of atrial fibrillation a right apical TPS implantation was performed earlier. Four weeks prior to presentation at our facility an unsuccessful CV with a maximum biphasic energy level of 360J was performed, after which amiodarone was initiated. At the time of presentation three shocks with 100 J, 200 J and 360 J were delivered without sustained restoration of a stable sinus rhythm. Patches were in an anterior-posterior position. No complications and no significant changes in device parameters in comparison to the pre-acquired values were observed. To our knowledge, this is the first case report of an external CV in a patient with a TPS. External CV in patients with a preexisting TPS seems to be safe and feasible.

Competing Interests: Disclosures Dr Epstein has received consulting fees from Philips, Abbott, Boston Scientific, and Medtronic. The rest of the authors report no conflicts of interest.

Management of rhythm related issues might be particularly challenging in patients with congenital heart disease due to complex anatomy and restricted vascular access. The leadless technology appears a suitable and attractive alternative for this population. We describe a patient with single ventricle physiology who successfully underwent implantation of a leadless pacemaker.

Background: The impact of sex in clinical and procedural outcomes in leadless pacemaker (LPM) patients has not yet been investigated., Objective: The purpose of this study was to investigate sex-related differences in patients undergoing LPM implantation., Methods: Consecutive patients enrolled in the i-LEAPER registry were analyzed. Comparisons between sexes were performed within the overall cohort using an adjusted analysis with 1:1 propensity matching for age and comorbidities. The primary outcome was the comparison of major complication rates. Sex-related differences regarding electrical performance and all-cause mortality during follow-up were deemed secondary outcomes., Results: In the overall population (n = 1179 patients; median age 80 years), 64.3% were men. After propensity matching, 738 patients with no significant baseline differences among groups were identified. During median follow-up of 25 [interquartile range 24-39] months, female sex was not associated with LPM-related major complications (hazard ratio [HR] 2.03; 95% confidence interval [CI] 0.70-5.84; P = .190) or all-cause mortality (HR 0.98; 95% CI 0.40-2.42; P = .960). LPM electrical performance results were comparable between groups, except for a higher pacing impedance in women at implant and during follow-up (24 months: 670 [550-800] Ω vs 616 [530-770] Ω; P = .014) that remained within normal limits., Conclusion: In a real-world setting, we found differences in sex-related referral patterns for LPM implantation with an underrepresentation of women, although major complication rate and LPM performance were comparable between sexes. Female patients showed higher impedance values, which had no impact on overall device performance. Electrical parameters remained within normal limits in both groups during the entire follow-up., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)