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Dual-chamber leadless pacemakers (LLPMs) consist of two implants, one in the right atrium and one in the right ventricle. Inter-device communication, required for atrioventricular (AV) synchrony, however, reduces the projected longevity of commercial dual-chamber LLPMs by 35–45%. This work analyzes the power-saving potential and the resulting impact on AV-synchrony for a novel LLPM synchronization protocol. Relevant parameters of the proposed window scheduling algorithm were optimized with system-level simulations investigating the resulting trade-off between transceiver current consumption and AV-synchrony. The parameter set included the algorithm's setpoint for the target number of windows per cardiac cycle and the number of averaging cycles used in the window update calculation. The sensing inputs for the LLPM model were derived from human electrocardiogram recordings in the MIT-BIH Arrhythmia Database. Transceiver current consumption was estimated by combining the simulation results on the required communication resources with electrical measurements of a receiver microchip developed for LLPM synchronization in previous work. The performance ratio given by AV-synchrony divided by current consumption was maximized for a target of one window per cardiac cycle and three averaging cycles. Median transceiver current of both LLPMs combined was 166 nA (interquartile range: 152–183 nA) and median AV-synchrony was 92.5%. This corresponded to median reduction of 18.3% and 3.2% in current consumption and AV-synchrony, respectively, compared to a non-rate-responsive implementation of the same protocol, which prioritized maximum AV-synchrony. In conclusion, adopting a rate-responsive communication protocol may significantly increase device longevity of dual-chamber LLPMs without compromising AV-synchrony, potentially reducing the frequency of device replacements. [ABSTRACT FROM AUTHOR]

Background: Transvenous lead extraction (TLE) for cardiovascular implantable electronic device (CIED)‐related infections has increased. The incidence of TLE in nonagenarians is low, with limited reports outlining the outcomes of this procedure. Therefore, in this study, we aimed to clarify the outcomes of TLE in nonagenarians. Methods: Patients with TLE treated at our hospital between 2014 and 2023 were retrospectively examined; patient characteristics, device type, indications, procedures, complications, and clinical data of nonagenarians were analyzed. Results: Of 12 patients with 24 leads (active fixation lead, n = 11; passive fixation lead, n = 13) who underwent TLE, the indication for TLE was infection (pocket infection, n = 8; sepsis, n = 4). Methicillin‐resistant Staphylococcus epidermidis was the most frequently identified causative agent (n = 4). The median patient age was 91 years; five patients were female. The median lead dwell time was 9 years. Excimer laser sheath (16 leads), mechanical sheath (five leads), Evolution RL (one lead), and manual traction (two leads) were employed in TLE. The procedure was successful in all patients, and only one had a minor complication. Six patients required CIED re‐implantation, and leadless pacemakers were selected for five patients. The 30‐day mortality after TLE was 0%. Conclusion: TLE can be safely performed in nonagenarians. The decision to perform TLE should not be based on old age alone; the suitability of removing infected CIEDs should be determined based on each patient's condition. [ABSTRACT FROM AUTHOR]

Introduction: Severe obesity presents significant challenges in imaging and delivery of therapy, including pacemaker implant. Methods and Result: We present our experience implanting a leadless pacemaker (LP) in a severely obese man presenting with heart block. We describe our multidisciplinary approach using right internal jugular venous access and transesophageal imaging in lieu of fluoroscopy which failed to provide workable images in this instance. Conclusion: Ultrasound guided LP placement may have wider application in the midst of an ongoing obesity epidemic where fluoroscopy imaging is both limited and unsafe. [ABSTRACT FROM AUTHOR]

Background: Roughly one in six patients receiving conventional transvenous pacemaker systems experience significant complications within 1 year of implant, mainly due to the transvenous lead and subcutaneous pocket. A new helix-fixation single-chamber ventricular leadless pacemaker (LP) system capable of pre-deployment exploratory electrical mapping is commercially available. Such an LP may mitigate complications while streamlining the implantation. In this study, the initial real-world implant experience of the helix-fixation LP was evaluated following its commercial release. Methods: In patients indicated for single-chamber right ventricular pacing, helix-fixation Aveir VR LPs (Abbott, Abbott Park, IL) were implanted using the dedicated loading tool, introducer, and delivery catheter. Implant procedural characteristics, electrical parameters, and any 30-day procedure-related adverse events of consecutive implant attempts were retrospectively evaluated. Results: A total of 167 patients with Class I indication for permanent pacing received implants in four North American centers (57% male, 70 years old). Pre-fixation electrical mapping of potential sites allowed repositioning to be avoided in 95.7% of patients. Median [interquartile range] LP procedure and fluoroscopy durations were 25.5 min [20.0, 35.0] and 5.7 min [4.0, 9.2], respectively. Pacing capture threshold, sensed R-wave amplitude, and impedance were 0.8 V [0.5, 1.3], 9.0 mV [6.0, 12.0], and 705 Ω [550, 910], respectively. Implantation was successful in 98.8% of patients, with 98.2% free from acute adverse events. Conclusions: The initial, real-world experience of the helix-fixation ventricular leadless pacemaker demonstrated safe and efficient implantation with minimal repositioning, viable electrical metrics, and limited acute complications. Helix-fixation single-chamber ventricular leadless pacemakers were implanted in 167 patients, with a median procedure time of 25.5 minutes, 98.8% implant success, and 98.2% freedom from acute adverse events. [ABSTRACT FROM AUTHOR]

Background: Leadless cardiac pacemakers (LCPs) are emerging as viable alternatives to conventional transvenous pacemakers (TVPs). This study aimed to systematically compare the postoperative outcomes of LCPs and TVPs based on available published studies. Methods: We conducted a systematic review and meta-analysis of literature comparing outcomes from LCP and TVP implantations. Data analysis was performed using Stata/MP 17.0. The evaluated endpoints included pericardial effusion or perforation, puncture site events, infective endocarditis, lead or device dislodgement, pocket-related complications, tricuspid regurgitation or dysfunction, any infection, increased right ventricle (RV) pacing threshold, embolism, and thrombosis. Aggregated odds ratios (OR) and 95% confidence intervals (CI) were determined. Sensitivity analyses were conducted for heterogeneity if I2 was >50% or p < 0.01, otherwise, the random-effects model was chosen. Publication bias was analyzed if the number studies exceeded ten. Results: The meta-analysis included 24 observational studies with 78,938 patients, comprising 24,191 with LCP implantation and 54,747 with TVP implantation. The results indicated a significantly lower incidence of lead or device dislodgment (OR = 3.32, 95% CI: 1.91–5.77, p < 0.01), infective endocarditis (OR = 3.62, 95% CI: 3.10–4.24, p < 0.01), and infection (OR = 3.93, 95% CI: 1.67–9.24, p < 0.01) in the LCP group compared to the TVP group. In contrast, incidences of puncture site complications (OR = 0.24, 95% CI: 0.19–0.32, p < 0.01) and pericardial effusion or perforation (OR = 0.33, 95% CI: 0.28–0.39, p < 0.01) were significantly higher in the LCP group. Conclusions: Compared with TVP, LCP implantation is associated with a lower risk of infective endocarditis, lead or device dislodgment, infections, and pocket-related complications. However, LCP implantation carries a higher risk of puncture site complications and pericardial effusion or perforation. These findings underscore the need for careful consideration of patient-specific factors when choosing between LCP and TVP implantation. [ABSTRACT FROM AUTHOR]

Introduction: Conventional implantable cardioverter-defibrillators (ICDs) and pacemakers carry a risk of pocket- and lead-related complications in particular. To avoid these complications, extravascular devices (EVDs) have been developed, such as the subcutaneous ICD (S-ICD) and leadless pacemaker (LP). However, data on patient or centre characteristics related to the actual adoption of EVDs are lacking. Objective: To assess real-world nationwide trends in EVD adoption in the Netherlands. Methods: Using the Netherlands Heart Registration, all consecutive patients with a de novo S‑ICD or conventional single-chamber ICD implantation between 2012–2020, or de novo LP or conventional single-chamber pacemaker implantation between 2014–2020 were included. Trends in adoption are described for various patient and centre characteristics. Result: From 2012–2020, 2190 S‑ICDs and 10,683 conventional ICDs were implanted; from 2014–2020, 712 LPs and 11,103 conventional pacemakers were implanted. The general use has increased (S-ICDs 8 to 21%; LPs 1 to 8%), but this increase seems to have reached a plateau. S‑ICD recipients were younger than conventional ICD recipients (p < 0.001) and more often female (p < 0.001); LP recipients were younger than conventional pacemaker recipients (p < 0.001) and more often male (p = 0.03). Both S‑ICDs and LPs were mainly implanted in high-volume centres with cardiothoracic surgery on-site, although over time S‑ICDs were increasingly implanted in centres without cardiothoracic surgery (p < 0.001). Conclusion: This nationwide study demonstrated a relatively quick adoption of innovative EVDs with a plateau after approximately 4 years. S‑ICD use is especially high in younger patients. EVDs are mainly implanted in high-volume centres with cardiothoracic surgery back-up, but S‑ICD use is expanding beyond those centres. [ABSTRACT FROM AUTHOR]

The halo-shape technique (HST) is an emerging approach for implanting a leadless pacemaker in scoliosis patients in recent years. Severe scoliosis and humpback made it challenging to push the tip of the delivery catheter towards the ventricular septum using the conventional gooseneck-shape technique. The feasibility and safety of the use of HST in an octogenarian with severe dextroscoliosis and humpback have not been well-assessed. Here, we report a case of high-degree atrioventricular block octogenarian with severe dextroscoliosis and humpback who successfully received a leadless pacemaker implantation using HST. Procedure-related complications were not observed, and the electrical parameters were stable at 6-month follow-up. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. 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. [Display omitted] [ABSTRACT FROM AUTHOR]

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. This meta-analysis aimed to assess complication rates after modern electrophysiology procedures during the lifetime of the procedures. 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). 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). Despite an increase in cardiac electrophysiology procedures, procedural safety has improved over time. [ABSTRACT FROM AUTHOR]

This paper studies the development of piezoelectric energy harvesting for self-powered leadless intracardiac pacemakers. The energy harvester fit inside the battery compartment, assuming that the energy harvester would replace the battery with a smaller rechargeable battery capacity. The power output analysis was derived from the three-dimensional finite element analysis and in vivo heart measurements. A Doppler laser at the anterior basal in the right ventricle directly measured the heart's kinetic motion. Piezoceramics in the cantilevered configuration were studied. The heart motion was periodic but not harmonic and shock-based. This study found that energy can be harvested by applying periodic bio-movements (cardiac motion). The results also showed that the energy harvester can generate 1.1 V voltage. The effect of various geometrical parameters on power generation was studied. This approach offers potential for self-powered implantable medical devices, with the harvested energy used to power devices such as pacemakers. [ABSTRACT FROM AUTHOR]

ObjectiveTo explore the left and right ventricular myocardial strain and dyssynchrony in patients with Micra AV leadless pacing implantation, and to further analyze the impact of implantation site on myocardial strain and dyssynchrony. MethodsA retrospective study was conducted on 43 patients with Micra AV implantation and 20 patients with high-degree atrioventricular block (Ⅱdegree typeⅡand Ⅲ degree atrioventricular block) at the Department of Cardiology, Zhongshan Hospital from April 2023 to December 2023. The demographic information and clinical characteristics of the patients were collected. Echocardiography and speckle tracking imaging techniques were used to obtain conventional echocardiographic parameters, myocardial strain, and dyssynchrony indices of patients in the two groups, including global longitudinal strain (GLS), free wall longitudinal strain (FWLS), peak strain dispersion (PSD) of 18 left ventricular segments, PSD of 6 right ventricular segments, and other indices. According to the implantation location of Micra AV, the patients were further divided into middle group (right ventricular septum), high group (right ventricular inflow tract), and low group (apical region), and the differences in myocardial strain and dyssynchrony indices among the three subgroups were compared. ResultsThe left ventricular GLS (LVGLS), right ventricular GLS (RVGLS), and right ventricular FWLS (RVFWLS) of the Micra AV group were significantly lower than those of the conduction block group (P＜0.001), and the right ventricular dyssynchrony of the Micra AV group was significantly higher than that of the conduction block group (P＜0.05). Comparison of myocardial strain and dyssynchrony at different implantation sites showed that the LVGLS of the high implantation group was significantly higher than that of the middle and low implantation groups, and the left ventricular dyssynchrony index Yu was significantly lower than that of the middle group (P＜0.05); the right ventricular ejection fraction (RVEF) of the low implantation group was significantly lower than that of the high group, and the right ventricular 6-segment PSD was significantly higher than that of the middle and high implantation groups (P＜0.05). ConclusionsCompared with patients with high-degree atrioventricular block, patients with Micra AV leadless pacing have reduced left and right ventricular strain, and the implantation of low position had greater effect.

Abstract The halo-shape technique (HST) is an emerging approach for implanting a leadless pacemaker in scoliosis patients in recent years. Severe scoliosis and humpback made it challenging to push the tip of the delivery catheter towards the ventricular septum using the conventional gooseneck-shape technique. The feasibility and safety of the use of HST in an octogenarian with severe dextroscoliosis and humpback have not been well-assessed. Here, we report a case of high-degree atrioventricular block octogenarian with severe dextroscoliosis and humpback who successfully received a leadless pacemaker implantation using HST. Procedure-related complications were not observed, and the electrical parameters were stable at 6-month follow-up.

Evidence is limited regarding the effectiveness of leadless pacemaker implantation for conduction disturbance following transcatheter aortic valve replacement (TAVR). This study sought to examine the national trends in the use of leadless pacemaker implantation following TAVR and compare its performance with transvenous pacemakers. 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. 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). 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. [Display omitted] [ABSTRACT FROM AUTHOR]

Introduction: Leadless pacemakers are associated with a low risk of infection, so indications for their removal are rare. One can expect that the dwell time of the device correlates with a more difficult removal, but it has not been proved so far. Methods and Results: We present a case of a patient in whom MICRA transcatheter pacing system was successfully removed with nondedicated commercially available tools, 70 months after implantation. Conclusion: A successful removal of the MICRA leadless pacemaker is possible, and may be safe even many years after the device implantation, despite a lack of dedicated tools. Due to the potential risk of complications, the benefits and risks of the procedure should be weighted before making a final decision. [ABSTRACT FROM AUTHOR]

Objective: This study evaluates the feasibility and efficacy of implanting a leadless pacemaker at the right atrial appendage (RAA) in a preclinical minipig model, aiming to address the limitations of atrial pacing with current leadless devices like the Medtronic Micra, which is typically used for right ventricular implantation. Methods: Four minipigs, each with a median body weight of 45.8 ± 10.0 kg, underwent placement of the Micra transcatheter pacing system (TPS) via the right femoral vein into the RAA apex. The pacing performance was assessed over 1‐week (short‐term) and 3‐month (long‐term) periods. Outcomes: The initial findings indicated successful implantation, with satisfactory intrinsic R‐wave amplitudes and pacing threshold. In the following period, the sensitivity, threshold, and impedance were stable with time. Notably, upon explanation at 3 months, a deep myocardial penetration by the device was observed, necessitating a redesign for safe long‐term use in a growing subject's heart. Conclusion: While initial results suggest that RAA apex placement of the Micra TPS is promising for potential inclusion in a dual‐chamber pacing system, the issue of myocardial penetration highlights the need for device redesign to ensure safety and effectiveness in long‐term applications. [ABSTRACT FROM AUTHOR]

A 41‐year‐old male presented with syncope whilst eating and was subsequently demonstrated to have recurrent symptomatic sinus pauses whilst swallowing. Following the exclusion of structural heart disease, he was diagnosed with swallow syncope, an uncommon variant of neurocardiogenic syncope. To avoid long‐term complications of a transvenous pacemaker, the case was managed with a leadless pacemaker which resulted in complete resolution of symptoms. [ABSTRACT FROM AUTHOR]

This special article is a continuation of an annual series for the Journal of Cardiothoracic and Vascular Anesthesia , highlighting the latest developments in the field of electrophysiology, particularly concerning cardiac anesthesiologists. The selected topics in the specialty for 2023 include consensus statements on left atrial appendage closure, outcomes in patients with atrial fibrillation and heart failure after ablation, further developments in the field of pulse field ablation, alternate defibrillation strategies for refractory ventricular fibrillation, updates on conduction system pacing, new devices such as the Aurora EV system and AVEIR leadless pacemaker system, artificial intelligence and its use in electrocardiogram-based diagnosis and latest evidence regarding the impact of anesthetic techniques on patient outcomes undergoing electrophysiology procedures. [ABSTRACT FROM AUTHOR]

Background: Permanent pacing is often required following valve intervention (either surgical or percutaneous); however, tricuspid interventions pose specific challenges to conventional pacing. Therefore, leadless pacemaker (LP) implantation may be the preferred strategy when permanent pacing is required after tricuspid valve intervention. Purpose: To report periprocedural outcomes and follow-up of patients undergoing implantation of a LP system following tricuspid valve interventions. Methods: Patients with previous tricuspid valve intervention at the time of attempted implantation of a LP (MicraTM, Medtronic, Minneapolis, MN, USA) were included. Results: Between 2019 and 2022, 40 patients underwent LP implantations following tricuspid interventions in 5 large tertiary centers. The mean age was 68.9 ± 13.7 years, and 48% patients were male. The indication for pacing was as following: AVB in 27 (68%) patients, AF with slow ventricular response in 10 (25%) patients, and refractory rapid atrial fibrillation (AF) referred to AV junction ablation in 3 (7%) patients. Most of the patients received Micra VR (78%). The procedure was successful in all patients. The mean procedural time is 58 ± 32 min, and the median fluoroscopy time is 7.5 min. Electrical parameters were within normal range (threshold: 1.35 ± 1.2 V@0.24 ms, impedance: 772 ± 245 Ohm, R-wave: 6.9 ± 5.4 mV). No acute complications were observed. During a mean follow-up of 10 months, electrical parameters remained stable, and 4 deaths were occurred (not related to the procedure). Conclusion: A LP is a safe and efficient option following tricuspid valve interventions. [ABSTRACT FROM AUTHOR]

Background: Leadless pacemakers (LPs) are promising alternatives to traditional transvenous pacemakers (TVPs), but their comparative effectiveness and safety in clinical outcomes remain uncertain. Methods: We systematically searched PubMed, Embase, Scopus, Cochrane, and ClinicalTrials.gov for studies comparing LPs and TVPs. A restricted maximum likelihood random-effects model was used for all outcomes. Heterogeneity was assessed using I2 statistics. We performed a subgroup analysis with studies with multivariate-adjusted data. Results: We included 21 studies involving 47,229 patients, of whom 12,199 (25.8%) underwent LP implantation. Compared with TVPs, LPs were associated with a significantly lower risk of overall complications (OR 0.61; 95% CI 0.45–0.81; p < 0.01), dislodgement (OR 0.34; 95% CI 0.20–0.56; p < 0.01), and pneumothorax (OR 0.27; 95% CI 0.16–0.46; p < 0.01). No significant difference in all-cause mortality was observed in the overall analysis (OR 1.43; 95% CI 0.65–3.15; p = 0.35) and in studies with multivariate-adjusted data (OR 1.34; 95% CI 0.65–2.78; p = 0.43). However, LPs were associated with a higher risk of pericardial effusion (OR 2.47; 95% CI 1.39–4.38; p < 0.01) and cardiac tamponade (OR 3.75; 95% CI 2.41–5.83; p < 0.01). LPs also demonstrated a lower pacing capture threshold (MD -0.19 V; 95% CI [-0.23 V]-[-0.16 V]; p < 0.01), but no significant difference in impedance (MD 32.63 ohms; 95% CI [-22.50 ohms]-[87.76 ohms]; p = 0.25). Conclusions: These findings suggest that LPs were associated with lower overall complication rates and similar effectiveness to TVPs. However, randomized controlled trials are warranted to validate these results. [ABSTRACT FROM AUTHOR]

Introduction: Leadless pacemakers (LPM) have established themselves as the important therapeutic modality in management of selected patients with symptomatic bradycardia. To determine real‐world utilization and in‐hospital outcomes of LPM implantation since its approval by the Food and Drug Administration in 2016. Methods: For this retrospective cohort study, data were extracted from the National Inpatient Sample database from the years 2016−2020. The outcomes analyzed in our study included implantation trends of LPM over study years, mortality, major complications (defined as pericardial effusion requiring intervention, any vascular complication, or acute kidney injury), length of stay, and cost of hospitalization. Implantation trends of LPM were assessed using linear regression. Using years 2016−2017 as a reference, adjusted outcomes of mortality, major complications, prolonged length of stay (defined as >6 days), and increased hospitalization cost (defined as median cost >34 098$) were analyzed for subsequent years using a multivariable logistic regression model. Results: There was a gradual increased trend of LPM implantation over our study years (3230 devices in years 2016−2017 to 11 815 devices in year 2020, p for trend <.01). The adjusted mortality improved significantly after LPM implantation in subsequent years compared to the reference years 2016−2017 (aOR for the year 2018: 0.61, 95% CI: 0.51−0.73; aOR for the year 2019: 0.49, 95% CI: 0.41−0.59; and aOR for the year 2020: 0.52, 95% CI: 0.44−0.62). No differences in adjusted rates of major complications were demonstrated over the subsequent years. The adjusted cost of hospitalization was higher for the years 2019 (aOR: 1.33, 95% CI: 1.22−1.46) and 2020 (aOR: 1.69, 95% CI: 1.55−1.84). Conclusion: The contemporary US practice has shown significantly increased implantation rates of LPM since its approval with reduced rates of inpatient mortality. [ABSTRACT FROM AUTHOR]

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. 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. 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). Eighty patients (median age 82 years; female 55%; mean body mass index [BMI] 25.8 kg/m2) 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/s2. We found a significant correlation of A4 signal amplitude and overall atrioventricular synchrony (P =.013). 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. [ABSTRACT FROM AUTHOR]

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. 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). 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. 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/s2; n = 26), and low-A4 group (A4 amplitude ≤2.5 m/s2; 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). 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. [Display omitted] [ABSTRACT FROM AUTHOR]

The article discusses the development and potential benefits of the AVEIR DR dual-chamber leadless pacemaker system for managing bradycardia. The AVEIR system is the world's first dual-chamber leadless pacing system, combining an atrial and ventricular leadless pacemaker. It offers improvements over previous leadless pacemakers, including enhanced battery capacity and improved AV synchrony. The article highlights the implantation and retrieval process of the AVEIR device, as well as its clinical efficacy and safety. However, long-term data on the device's safety profile and battery longevity are still lacking. Overall, the AVEIR system shows promise in reshaping clinical practices for bradycardia management. [Extracted from the article]

Aims Significant changes in tricuspid regurgitation (TR) and mitral regurgitation (MR) post-cardiac implantable electronic devices (CIEDs) are increasingly recognized. However, uncertainty remains as to whether the risk of CIED-associated TR and MR differs with right ventricular pacing (RVP) via CIED with trans-tricuspid RV leads, compared with cardiac resynchronization therapy (CRT), conduction system pacing (CSP), and leadless pacing (LP). The study aims to synthesize extant data on risk and prognosis of significant post-CIED TR and MR across pacing strategies. Methods and results We searched PubMed, EMBASE, and Cochrane Library databases published until 31 October 2023. Significant post-CIED TR and MR were defined as ≥ moderate. Fifty-seven TR studies (n = 13 723 patients) and 90 MR studies (n = 14 387 patients) were included. For all CIED, the risk of post-CIED TR increased [pooled odds ratio (OR) = 2.46 and 95% CI = 1.88–3.22], while the risk of post-CIED MR reduced (OR = 0.74, 95% CI = 0.58–0.94) after 12 and 6 months of median follow-up, respectively. Right ventricular pacing via CIED with trans-tricuspid RV leads was associated with increased risk of post-CIED TR (OR = 4.54, 95% CI = 3.14–6.57) and post-CIED MR (OR = 2.24, 95% CI = 1.18–4.26). Binarily, CSP did not alter TR risk (OR = 0.37, 95% CI = 0.13–1.02), but significantly reduced MR (OR = 0.15, 95% CI = 0.03–0.62). Cardiac resynchronization therapy did not significantly change TR risk (OR = 1.09, 95% CI = 0.55–2.17), but significantly reduced MR with prevalence pre-CRT of 43%, decreasing post-CRT to 22% (OR = 0.49, 95% CI = 0.40–0.61). There was no significant association of LP with post-CIED TR (OR = 1.15, 95% CI = 0.83–1.59) or MR (OR = 1.31, 95% CI = 0.72–2.39). Cardiac implantable electronic device–associated TR was independently predictive of all-cause mortality [pooled hazard ratio (HR) = 1.64, 95% CI = 1.40–1.90] after median of 53 months. Mitral regurgitation persisting post-CRT independently predicted all-cause mortality (HR = 2.00, 95% CI = 1.57–2.55) after 38 months. Conclusion Our findings suggest that, when possible, adoption of pacing strategies that avoid isolated trans-tricuspid RV leads may be beneficial in preventing incident or deteriorating atrioventricular valvular regurgitation and might reduce mortality. [ABSTRACT FROM AUTHOR]

Introduction: Few studies have demonstrated a high degree of atrioventricular (AV) synchrony with a new leadless pacemaker called Micra AV. Our group previously reported a new and unique sensing method. We believe that this novel sensing method, "Simplified A3 method," might facilitate better AV synchrony than a conventional sensing method in almost all cases with Micra AV implantation. Methods: We conducted a non‐randomized retrospective study comparing the two pacing methods at two centers. From December 1, 2021 to October 31, 2022, Micra AV was implanted for 32 patients at the two centers. Twenty of the 32 patients with sinus rhythm and complete AV block were included in this study. In Group 1, the conventional setting was programmed as follows: auto A3 threshold, auto A3 window‐end (WE), and auto A4 threshold turned on during hospitalization. In Group 2, the "Simplified A3 method" was programmed as follows: auto A3 threshold and auto A3WE turned off. Instead, an intentionally prolonged A3WE (850–1000 ms) and low A3 threshold (A3 signal amplitude + 0.5–1.0 m/s2) were programmed. Results: Twenty patients were analyzed. In Group 2, AV synchrony (%AMVp) was significantly higher at the first outpatient clinic (63.0 ± 5.7% vs 81.0 ± 4.2%, p =.03). A3 threshold was significantly lower in Group 2 (5.9 ± 0.7 m/s2, p <.05 vs 2.3 ± 0.5 m/s2, p <.05). Conclusion: Our novel sensing method might be a more feasible sensing method for obtaining higher AV synchrony than the conventional algorithm. [ABSTRACT FROM AUTHOR]

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. 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. 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 %. 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. • Conduction Abnormalities requiring pacemaker implantation after TAVR are common. • Leadless pacemaker technology has emerged as a safe alternative to transvenous systems. • Leadless pacemaker implantation after TAVR is safe, feasible, and associated with low periprocedural complications. [ABSTRACT FROM AUTHOR]

Leadless pacemaker systems (LPs) were developed as an alternative to traditional transvenous permanent pacemakers (TV-PPM) due to increasing rates of device and procedural related complications, leading to a high-cost burden to our health-care system. LPs were initially indicated for single-chamber ventricular pacing; however, recent developments have allowed for dual-chamber pacing too. These systems have demonstrated highly successful implant rates with stable pacing performance. This article describes the retrieval techniques of the Micra LPs and ways to mitigate challenges encountered during the retrieval process. [ABSTRACT FROM AUTHOR]

The article focuses on a case of a 76-year-old male with progressive AV nodal conduction disease who experienced an episode of complete AV block and subsequently underwent leadless pacemaker implantation. Topics include the patient's postoperative complications with persistent hiccups, pacemaker interrogation findings, and the management approach, including the prescription of colchicine for possible device-related inflammation.

The pacing threshold is important for leadless pacemakers, as the pacing output has a significant impact on battery longevity. Acute pacing rate‐dependent threshold increases have also been reported with leadless pacemakers. In the present case, we experienced a case in which the threshold, which had been raised in the acute phase, once showed a tendency to improve, but then worsened again. And, as in previous reports, thresholds improved completely in the chronic phase. Repeated retrieval and reimplantation of leadless pacemakers increases the likelihood of fatal complications, so being aware of such phenomenon may prevent unnecessary procedure and complications. [ABSTRACT FROM AUTHOR]

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.

Key Clinical Message: Atrial fibrillation ablation, including pulmonary vein isolation immediately after left atrial appendage closure (LAAC), is a rare and challenging issue. Intracardiac echocardiography guidance can help identify the LAAC device position for safe atrial fibrillation ablation without LAAC device‐related adverse events even immediately after LAAC device implantation. Early phase atrial fibrillation (AF) ablation after left atrial appendage closure (LAAC) is a rare and challenging issue. Here, we present a case illustrating the feasibility of AF ablation under intracardiac echocardiography guidance immediately after LAAC device implantation without LAAC device‐related adverse events. [ABSTRACT FROM AUTHOR]

The subclavian vein is typically used in cardiovascular implantable electronic device (CIED) implantations. External stress on the subclavian vein can lead to lead‐related complications. There are several causes of this stress, such as frequent upper extremity movements or external injury. Venous thoracic outlet syndrome (TOS) can also become the cause of external lead stress. However, the diagnosis of venous TOS can be challenging because subclavian venography can appear normal at first glance. We present a unique case of a device infection in a patient with venous TOS. A careful observation of the imaging studies is vital for diagnosing venous TOS and a leadless pacemaker implantation could be an alternative therapeutic option. [ABSTRACT FROM AUTHOR]

Conventional pacing systems consist of a pacemaker and one or more leads threaded from the device pocket through veins into the heart conducting the pacing therapy to the desired pacing site. Although these devices are effective, approximately one in eight patients treated with these traditional pacing systems experiences a complication attributed to the pacemaker pocket or leads. With the technological advances in electronics, leadless pacemakers that small enough to implant within the heart were introduced. Leadless pacemakers have been developed to overcome many of the challenges of transvenous pacing including complications related to leads or pacemaker pockets. This review aims to provide an overview of advantages of leadless pacemaker, complications and limitations of leadless pacemaker, leadless pacemaker candidate, and future directions of this promising technology. [ABSTRACT FROM AUTHOR]

Purpose of Review: Tricuspid regurgitation is a commonly encountered valvular pathology in patients with trans-tricuspid pacing or implantable cardioverter-defibrillator leads. Transcatheter tricuspid valve interventions are increasingly performed in patients at high surgical risk. Implantation of these valves can lead to the "jailing" of a trans-tricuspid lead. This practice carries both short- and long-term risks of lead failure and subsequent infection without the ability to perform traditional transvenous lead extraction. Herein, this manuscript reviews available therapeutic options for lead management in patients undergoing transcatheter tricuspid valve interventions. Recent Findings: The decision to jail a lead may be appropriate in certain high-risk cases, though extraction may be a better option in most cases given the variety of options for re-implant, including leadless pacemakers, valve-sparing systems, epicardial leads, leads placed directly through prosthetic valves, and the completely subcutaneous implantable-defibrillator. Summary: A growing number of patients meet the requirement for CIED implantation in the United States. A significant proportion of these patients will have tricuspid valve dysfunction, either related to or independent of their transvenous lead. As with any percutaneous intervention that has shown efficacy, the role of TTVI is also likely to increase as this therapy advances beyond the investigational phase. As such, the role of the heart team in the management of these patients will be increasingly critical in the years to come, and in those patients that have pre-existing CIED leads, we advocate for the involvement of an electrophysiologist in the heart team. [ABSTRACT FROM AUTHOR]

The strategy after battery depletion was not established in Micra leadless pacemaker system (Micra). There are still some concerns in the 2nd Micra implantation, such as the mechanical interaction between both devices. The position of the 2nd Micra should be placed apart from the 1st Micra. We present a case of 1st Micra battery depletion who successfully underwent the 2nd Micra implantation under the intracardiac echo guidance. In our case, intracardiac echo was a very effective tool for confirming the location of Micra implantation. [ABSTRACT FROM AUTHOR]

The second generation of transcatheter pacing systems, called Micra AV, can provide atrioventricular (AV) synchronous pacing via a new pacing algorithm relying on sensing mechanical atrial contraction. Several novel programming parameters were introduced to enable AV synchronous pacing, including an A3 window and A4 window as well as a conduction mode switch and an activity mode switch. In addition to several automated features, manual programming optimization of some of the novel parameters is key to improving AV synchrony. A solid knowledge of the features and their programming is essential for electrophysiologists implanting or following patients with Micra AV devices. Differences in programming optimization might partially explain the high variability of AV synchrony published in real-world data reports. This article reviews the key programming parameters of Micra AV. Subsequently, optimal programming recommendations for defined patient profiles are presented. Those were established by consensus within an expert panel comprised of 11 European electrophysiologists from high-volume Micra AV centres. The patient profiles were (1) high degree AV block and slow sinus rhythm; (2) high degree AV block and fast sinus rhythm; and (3) intermittent AV block. The panel recommended to evaluate the mechanical atrial activity on transthoracic echocardiography prior to implant. It was also agreed that Auto A3 Threshold and Tracking Check should be turned off in all patients, AV conduction mode switch should be turned off in all patients with high degree AV block, and the lower rate should be programmed to 50 bpm with exceptions based on individual clinical assessment. Future studies will be useful to evaluate the strength of those recommendations to improve the AV synchrony. [ABSTRACT FROM AUTHOR]

Aims Aveir VR performance and predictors for its pacing threshold (PCT) in a real-world cohort were investigated. Methods Electrical measurements at various stages of an Aveir VR implant were prospectively collected. Predictors for 3-month PCT were studied. A retrospective cohort of consecutive 139 Micra implants was used to compare the PCT evolution. High PCT was defined as ≥1.5 V, using a pulse width of 0.4 ms for Aveir and 0.24 ms for Micra. Excellent PCT was defined as ≤0.5 V at the respective pulse width. Results Among the 123 consecutive Aveir VR implant attempts, 122 (99.2%) were successful. The majority were of advanced age (mean 79.7) and small body size (mean BSA 1.60). Two patients (1.6%) experienced complications, including one pericardial effusion after device reposition and one intraoperative device dislodgement. Eighty-eight patients reached a 3-month follow-up. Aveir 3-month PCT was correlated with impedance at mapping (P = 0.015), tether mode (P < 0.001), end-of-procedure (P < 0.001), and mapping PCT (P = 0.035), but not with PCTs after fixation (P > 0.05). Tether mode impedance >470 ohms had 88% sensitivity and 71% specificity in predicting excellent 3-month PCT. Although it is more common for Aveir to have high PCT at end of procedure (11.5% for Aveir and 2.2% for Micra, P = 0.004), the rate at 3 months was similar (2.3% for Aveir and 3.1% for Micra, P = 1.000). Conclusion Aveir VR demonstrated satisfactory performance in this high-risk cohort. Pacing thresholds tend to improve to a greater extent than Micra after implantation. The PCT after fixation, even after a waiting period, has limited predictive value for the chronic threshold. Low-mapping PCT and high intraoperative impedance predict chronic low PCT. [ABSTRACT FROM AUTHOR]

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 pacemakers offer the opportunity to avoid transvenous hardware among patients with tricuspid valve prostheses. We present the first case of a helix-based fixation leadless pacemaker implanted through valve-in-valve tricuspid prostheses in a 43-year-old female with extensive prior cardiac history. At the time of presentation, epicardial pacing was no longer a viable option in the setting of pacemaker dependence. Placement of a helix-fixed, leadless right ventricular pacemaker was performed as a bridge to dual-chamber leadless pacing. This was safely and effectively performed and highlighted favorable procedural characteristics that included RV cavity dimensions and prosthesis type. [ABSTRACT FROM AUTHOR]

The procedural success in the implantation of cardiac electric devices depends on both the implanted position and the electric performance. The capture threshold and the pacing output affect the estimated battery longevity. In a case with a high capture threshold, recapture and reimplantation of a leadless pacemaker are commonly recommended. We experienced a case with the rate‐dependent elevation of the capture threshold following the implantation of a leadless pacemaker. The recognition of the rate‐dependency of the capture threshold and the acceptable programming could avoid the unnecessary recapture and reimplantation of that, avoiding the increase of procedural risks. [ABSTRACT FROM AUTHOR]

Introduction: Pacemaker implantation can be challenging in patients with congenital heart disease. Methods and Results: In a patient with Ebstein disease and symptomatic sinus node dysfunction, despite multiple attempts, the Micra® pacemaker could not be implanted in the severely dilated right ventricle. In that context, and after iodine injection to confirm the appropriate location, the Micra® pacemaker was successfully implanted in the right appendage at the first attempt. Conclusion: Despite the recent development of dedicated dual‐chamber leadless pacemaker, to the best of our knowledge, this case is the first off‐label Micra® implantation in a right appendage. [ABSTRACT FROM AUTHOR]

Abstract Background Leadless pacemaker therapy is associated with a significant reduction in lead-related complication rate compared to conventional transvenous single chamber pacemaker therapy. However, a significant complication rate of 1.2% was observed in vascular access due to the use of large delivery femoral sheath (27Fr). The aim of this study was to evaluate the effectiveness of real-time ultrasound guidance and Z suture technique in reducing total and major vascular complications in leadless pacemaker therapy. Method In this study, we performed a retrospective and prospective analysis of all adverse events associated with leadless pacemaker (Micra) implantation by two operators at a single tertiary center from December 2016 to December 2018. To mitigate the risk of vascular complications, all patients underwent real-time ultrasound-guided venipuncture for vascular access, as well as the application of a Z-suture technique for hemostasis at the end of the procedure. Data were collected on implant indications, implant procedure details, complications, and follow-up information. Results In this study, 45 patients with an age range of 24 to 94 years (mean 76 ± 14 years) were recruited, with 21 (46.6%) being female. The pacing indications for the patients included atrial fibrillation (24, 53.3%), vascular (7, 15.5%), infection (9, 20%), cognitive/frailty (3, 6.6%), and occupational (2, 4.4%). The implant procedures were performed under general anesthesia in 6 (13.3%) of the cases, and under local anesthesia and sedation in 39 (86.6%) of the cases. A single deployment was achieved in 43 (95.5%) of the patients, while 2 deployments were required in 2 (4.4%) of the patients. Notably, no vascular or major complications were reported in our cohort of patients. Conclusions The results of this observational study indicate that incorporating real-time ultrasound guidance during venipuncture and the use of a Z-suture technique significantly reduce the occurrence of both total and major vascular complications associated with the implantation of leadless pacemaker. However, more robust and larger studies are required in order to confirm these results and implications for clinical practice.