Leadless Pacemaker Implantation Research Articles

Intracardiac leadless versus transvenous permanent pacemaker implantation: Impact on clinical outcomes and healthcare utilization

BackgroundTransvenous permanent pacemakers are used frequently to treat cardiac rhythm disorders. Recently, intracardiac leadless pacemakers offer potential treatment using an alternative insertion procedure due to their novel design. Literature comparing outcomes between the two devices is scarce. We aim to assess the impact of intracardiac leadless pacemakers on readmissions and hospitalization trends. MethodsWe analyzed the National Readmissions Database from 2016 to 2019, seeking patients admitted for sick sinus syndrome, second-degree-, or third-degree atrioventricular block who received either a transvenous permanent pacemaker or an intracardiac leadless pacemaker. Patients were stratified by device type and assessed for 30-day readmissions, inpatient mortality, and healthcare utilization. Descriptive statistics, Cox proportional hazards, and multivariate regressions were used to compare the groups. ResultsBetween 2016 and 2019, 21,782 patients met the inclusion criteria. The mean age was 81.07 years, and 45.52 % were female. No statistical difference was noted for 30-day readmissions (HR 1.14, 95 % CI 0.92–1.41, p = 0.225) and inpatient mortality (HR 1.36, 95 % CI 0.71–2.62, p = 0.352) between the transvenous and intracardiac groups. Multivariate linear regression revealed that length of stay was 0.54 (95 % CI 0.26–0.83, p < 0.001) days longer for the intracardiac group. ConclusionHospitalization outcomes associated with intracardiac leadless pacemakers are comparable to traditional transvenous permanent pacemakers. Patients may benefit from using this new device without incurring additional resource utilization. Further studies are needed to compare long-term outcomes between transvenous and intracardiac pacemakers.

PO-05-027 INCIDENCE OF PACING-INDUCED CARDIOMYOPATHY AND NEED FOR CARDIAC RESYNCHRONIZATION THERAPY UPGRADE IN PATIENTS WITH LEADLESS PACEMAKER: LONG TERM FOLLOW-UP OF 75 PATIENTS

Excessive right ventricular (RV) pacing with traditional pacemaker has been associated with a 17-25% risk of pacing-induced cardiomyopathy (PICM), defined as a decrease of left ventricular ejection fraction by 10% or more. The risk of PICM with more septally placed leadless pacemaker is unknown. We aimed to report the incidence of PICM in patients with leadless pacemaker and the need for cardiac resynchronization therapy (CRT) upgrade. We performed a single-center analysis of patients who underwent leadless pacemaker implantation between January 1, 2014 and April 1, 2022. Patient echocardiogram result pre and post implantation were collected. The outcomes of this study included the incidence of PICM in leadless pacemaker implant patient, the rate of CRT upgrade, RV pacing percentage, total RV pacing time and follow up duration. The definition of total RV pacing time was the duration from pacemaker to last follow up multiplied by RV pacing percentage. A total 75 patients underwent leadless-pacemaker implantation were included in this study. The mean age was 80 ± 8.5 year-old. Indications for single chamber leadless implantation include sick sinus syndrome and bradycardia. Mean duration of follow up was 14.6 months. The RV pacing percentage was 64.4 ± 38.58 %.The mean RV pacing time was 9.2 ± 1.4 months, PICM was found in 32 patients (44%), 10 patients (13.5%) required CRT upgrade due to congestive heart failure symptoms. The mean duration between implantation of leadless pacemaker to upgrade CRT was 372 ± 489.8 days. The incidence of PICM in leadless pacemaker patients was 44% and 13.5 % of patients required CRT upgrade within 2 years after the leadless pacemaker implant in the majority of the patients. Further studies are necessary to confirm these findings.

PO-05-028 EVOLUTION IN SIGNIFICANT TRICUSPID REGURGITATION AFTER LEADLESS PACEMAKER IMPLANTATION

Lead induced tricuspid regurgitation (TR) is a known complication of cardiac implanted electronic devices and has been associated with increased rates of right heart failure, hospitalization, and death. Leadless pacemakers eliminate lead impingement on the valve leaflets but there are other mechanisms by which pacing may worsen TR. Data on the change in TR severity after leadless pacemaker implantation in patients with pre-existing significant TR are limited. To determine the change in TR after implantation of a leadless pacemaker system in patients with pre-existing moderate or greater TR. We performed a retrospective review of all leadless pacemaker implantations (Micra™ TPS, Medtronic) done at two hospitals between 2018 and 2021. Echocardiograms were obtained at baseline and at least 21 days after leadless pacemaker placement. Quartiles of TR were defined as none, mild, moderate, and severe. Patients were included for analysis if they had moderate or greater TR prior to implantation. Patients with a history of tricuspid valve surgery were excluded. Descriptive statistics were used to define the change in severity of TR after leadless pacemaker placement. Improvement was defined as decline in TR by at least one grade. Twenty-eight patients were included for analysis. Mean age was 79 years (range 57-97 years) and 61% of patients were female. Median RV pacing burden was 98%. The mean time from the procedure to follow up echo was 288 days (range 21 days-2.8 years). In 23 (83%) of patients TR remained stable or improved (Figure 1). Among the 21 patients with moderate TR, 5 (24%) developed severe TR while 9 (43%) had improvement. Four (57%) of the patients with severe TR had improvement. In this selected group of patients with pre-existing moderate or greater TR who underwent leadless pacemaker implantation, the majority unchanged or improved TR at follow up. These results suggest that leadless pacemakers do not adversely affect degree of TR. Future studies are planned in a larger, prospective population.

MP-453087-5 ADVERSE EVENTS ASSOCIATED WITH AVEIRTMVR LEADLESS PACEMAKER: A FOOD AND DRUG ADMINISTRATION MAUDE DATABASE STUDY

Since the first pacemaker implantation, much of the effort has been focused on battery longevity and device miniaturization. Leadless pacemaker offers an innovative approach to the treatment of bradyarrhythmias, thus avoiding long-term lead-related complications. Recently, the Aveir (screw-in type leadless pacemaker) (Abbott) has been approved by the Food and Drug Administration (FDA). We queried the FDA Manufacturer And User Facility Device Experience (MAUDE) database to study the safety profile and assess the types of complications with this relatively novel device technology. The MAUDE database is a repository of industry and patient/physician-reported medical device adverse events. A MAUDE database search was conducted on November 10, 2022, for reports received post-FDA approval to capture all adverse events. A total of 42 events (after removing duplicate entries or programmer or introducer sheath-related issues n=13) were reported for Aveir leadless pacemaker post-FDA approval. The most frequently reported issue was a device malfunction-related event (n=36, 85.7%). The most commonly encountered problem was the capture issue (28.6%, 12 events), followed by the sensing issue (19%, 8 events), high impedance (19%, 8 events), stretched helix (19%, 8 events), device dislodgement (14.3%, 6 events), device separation failure (14.3%, 6 events), premature separation (4.8%, 2 events), material twist (4.8%, 2 events), and broken helix (2.4%, 1 event). As such, this resulted in pericardial effusion requiring pericardiocentesis (9.5%, 4 events), cardiac perforation (9.5%, 4 events), and arrhythmia (2.4%, 1 event). This resulted in one death. Aveir leadless pacemaker implantation may be complicated by myocardial perforations and tears that result in cardiac tamponade and death. Our study is limited by heterogeneity in reporting, and lack of assessment of the total number of cases performed per year; thus, warranting better transparency and monitoring mechanisms.

The VR leadless pacemaker: Results of an expert panel using the RAND/UCLA method.

Leadless pacemakers were developed to reduce complications associated with transvenous pacemaker implantation and long-term follow-up. Existing international guidelines lack detailed instructions on patients suitable for leadless pacemaker implantation. Our aim was to develop a consensus document that provides medical guidance for all health professionals involved in the indication and implantation of Transcatheter Pacing System single-chamber device (VR leadless) pacemakers for patients with atrial fibrillation or in sinus rhythm. A panel of experts, including interventional and non-interventional cardiologists, used the Research ANd Development/University of California at Los Angeles (RAND/UCLA) method to rate the appropriateness of leadless pacemaker implantation for 64 scenarios in patients with atrial fibrillation and 192 scenarios in sinus rhythm. The scenarios were rated individually and again during a moderated group session. Median ratings and level of agreement were calculated to classify each scenario as appropriate, inappropriate, or questionable. This consensus statement, based on available literature and the experts' opinions, summarizes recommendations for standardizing and optimizing leadless pacemaker implantation. The limitation for vascular access via the superior vena cava was the most influential variable when indicating leadless pacemaker implantation in both patients with atrial fibrillation and patients in sinus rhythm. Life expectancy, risk of infection, prosthetic valve, left ventricular ejection fraction (LVEF), limitation for vascular access via the superior vena cava, and mobility and exercise capacity determine who is advised to undergo VR leadless pacemaker implantation. More prospective studies are needed to optimize existing recommendations.

Leadless pacemaker implantation in a univentricular heart in a patient with double-inlet left ventricle and L-transposition of the great arteries.

Leadless pacemaker implantation in a univentricular heart in a patient with double-inlet left ventricle and L-transposition of the great arteries.

Comparison of leadless pacemaker and conventional pacemaker for quality of life improvement in patients with bradyarrhythmias

Objective: To compare the improvement in quality of life (QoL) after implantation of leadless pacemakers (L-PM) with that of conventional pacemakers (C-PM) in patients with slow-onset arrhythmias. Methods: A total of 112 patients who received pacemaker implantation for the first time at Beijing Anzhen Hospital from January 2020 to July 2021 were selected, including 50 leadless pacemakers (L-PM) and 62 conventional pacemakers (C-PM). Clinical baseline data were collected, pacemaker-related complications and SF-36 scores were recorded and followed up at 1, 3, and 12 months post-operatively; SF-36 questionnaires and additional questionnaires were completed to compare the quality of life of the 2 groups; and factors associated with the change in QoL from baseline to 1, 3 and 12 months post-operatively were analyzed using multiple linear regression models. Results: The age of the 112 patients was (70.3±10.5) years, and 69 patients (61.6%) were male. The age of patients with L-PM and C-PM was (75.8±8.5) years and (67.5±10.4) years, respectively (P=0.004). In the L-PM group, 50 patients completed 1-, 3-, and 12-month follow-up. In the C-PM group, 62 patients completed the 1-month and 3-month follow-up, and 60 completed the 12-month follow-up. The C-PM group had a higher incidence of discomfort in the surgical area, impact of daily activities for the discomfort in the surgical area, and concern about heart or overall condition than the L-PM group on the additional questionnaire (all P values<0.05). After adjusting for age and SF-36 scores at baseline, at 12th month of follow-up, patients implanted with C-PM had lower values for quality of life PF, RP, SF, RE, and MH scores compared to patients implanted with L-PM, with beta values (95%CI) of -24.500 (-30.010--18.981), -27.118 (-32.997--21.239), -8.085 (-12.536--3.633), -4.839 (-9.437--0.241), -12.430 (-18.558--6.301), respectively (all P values<0.05). Conclusions: L-PM is associated with better QoL in slow arrhythmias patients, and patients who received L-PM reported less activity limitations due to surgical discomfort and less emotional distress.

Usefulness of leadless pacemaker implantation to continue chemotherapy for Burkitt's lymphoma without device infection despite repeated systemic infections.

Usefulness of leadless pacemaker implantation to continue chemotherapy for Burkitt's lymphoma without device infection despite repeated systemic infections.

Concomitant leadless pacing in pacemaker-dependent patients undergoing transvenous lead extraction for active infection: Mid-term follow-up

The rate of transvenous lead extraction (TLE) due to cardiac implantable electronic device (CIED) infection continues to rise. CIED infections are associated with significant morbidity and mortality. Temporary pacing in patients with active CIED infections after TLE can be challenging. Leadless pacing has emerged as an alternative approach in this patient population. The purpose of this study was to describe the outcomes of a strategy using concomitant leadless pacemaker implantation and TLE in patients with active infections and ongoing pacing requirements. This study involved all leadless pacemaker implantation procedures performed during TLE between June 2018 and September 2022 in the setting of active infection. Demographic characteristics, procedural details, and clinical outcomes were analyzed. The study included 86 patients with indications for ongoing pacing, 60 (70%) men with mean age 77.4 ± 10.5 years, who underwent TLE and concomitant leadless pacemaker implantation in the setting of active infection. There were no procedure-related complications. Sixty-five patients (76%) had evidence of bacteremia, 80% of whom were discharged to complete their antimicrobial treatment. During a median follow-up of 163 days (interquartile range 57-403 days), there were no recurrent infections. Of the 25 deaths (29%) during the study period, 22 (88%) were unrelated to the initial infection. Nine deceased patients (36%) had methicillin-resistant Staphylococcus aureus or Candida infections, 3 of whom had persistent infection despite TLE. Leadless pacing is a safe and efficacious approach for the management of patients with pacing requirements that undergo CIED extraction in the setting of active infection.

Leadless Micra pacemaker implantation in patient with previous Senning procedure for dextro-transposition of the great arteries

Leadless pacemakers have been developed with key advantages over traditional transvenous pacemakers by substantially mitigating the risks of device infection and lead related complications, and providing an alternative pacing strategy in patients with barriers to superior venous access. The Medtronic Micra leadless pacing system is designed for implantation through a femoral venous approach across the tricuspid valve, via Nitinol tine fixation into the trabeculated subpulmonic right ventricle. Patients with surgically corrected dextro-transposition of the great arteries (d-TGA) have an increased risk of pacing requirement. There is limited published experience of implantation of leadless Micra pacemakers in this population, with key challenges relating to trans-baffle access, and deployment of the device into the less trabeculated subpulmonic left ventricle. Here we describe a case report of leadless Micra implantation in a 49 year old male with d-TGA and Senning procedure in childhood, who required pacing for symptomatic sinus node disease, with anatomic barriers to transvenous pacing. Micra implantation was successfully performed following careful consideration of patient anatomy, including the utilisation of 3D modelling to guide the implantation procedure.

Leadless pacemaker implantation for pediatric patients through internal jugular vein approach: A case series of under 30 kg

BackgroundWe demonstrate a case series of 8 pediatric patients, all under 30 kg, who had leadless pacemaker implants via the internal jugular vein. MethodsA retrospective review of pediatric leadless pacing placement via the internal jugular vein at the University of Minnesota Masonic Children's Hospital and UC Davis Medical Center from 2018 through 2021 was performed. Rationales for pacing, demographics of patients, pacing thresholds, and longevity of devices were recorded. ResultsEight internal jugular pacemaker insertions were performed successfully in patients weighing between 10.9 kg and 29 kg. Five patients had Micra implantation via the right internal jugular vein, whereas 3 patients had insertion via the left internal jugular vein. No surgical cut-downs were performed. No venous complications occurred. Up to 3 years of follow-up were noted. ConclusionLeadless pacemaker implantation, via left or right internal jugular veins, is feasible without surgical cutdown in patients <30 kg

Retrieval of an infectious leadless pacemaker with vegetation.

This case discusses the retrieval of a pacemaker with vegetation from a 78-year-old man. It suggests that grasping side of Micra body and pulling Micra into Agilis sheath is a possible technique for retrieval.

Exploratory use of intraprocedural transesophageal echocardiography to guide implantation of the leadless pacemaker.

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. 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. 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. 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. 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.

Differences in patient characteristics, clinical practice and outcomes of cardiac implantable electric device therapy between Japan and the USA: a cross-sectional study using data from nationally representative administrative databases

ObjectivesTo identify differences in patient characteristics, clinical practice and outcomes of cardiac implantable electronic device (CIED) therapy between Japan and the USA.DesignA cross-sectional study.SettingNationally representative administrative databases from Japan and...

A Review of the Recent Advances of Cardiac Pacemaker Technology in Handling Complications.

The total number of annual pacemaker implantations continues to grow globally, and help patients with heart rhythm disorders with an improved quality of life and reduced mortality. The first implantable pacemakers appeared in 1965, characterized by their bulkiness, short battery life, and a single pacing mode. Innovation led to the modern pacemaker: a smaller system with improved battery life and capacity, and innovation in lead technology. Certain arrhythmia conditions may also qualify for leadless pacemaker implantation, thus eliminating the spectrum of complications that could occur with leads. Adverse events can be divided into acute (perforation, lead dislodgement, infection) and long-term (lead fractures, device infection, insulation failure). Traditional long-term complications with leads occur in 10% of patients, compared with device-related adverse effects observed in 6.7% of leadless pacemakers. Furthermore, cardiac pacemaker implantation results in quality of life improvements across all age groups. Large cardiac rehabilitation studies have demonstrated the effectiveness of exercise in reducing the physical complications involved with pacemaker implantation. Of the three randomized controlled trials examined, all of them reported some benefit of exercise in the intervention group compared with the control. The following review aims to discuss the multitude of pacemaker options potentially available for the clinician, complications, their course of management, and the path forward with innovations arising out of previous research within the field.

How to decrease the cost of pacemaker infection treatment by adopting seemingly costly innovation? A budget impact analysis of a leadless pacemaker implantation.

How to decrease the cost of pacemaker infection treatment by adopting seemingly costly innovation? A budget impact analysis of a leadless pacemaker implantation.

489 A RARE CASE OF LEAD EXTRACTION

Abstract Aims Poor data exist about the leadless PM implantation through a bioprosthetic tricuspid valve. Bioprosthetic tricuspid valve has traditionally represented a relative contraindication to transvenous right ventricular pacing for possible tricuspid bioprosthetic valve damage and dysfunction. Therefore, epicardial pacing is usually preferred to transvenous right pacing through a bioprosthetic tricuspid valve for the deleterious effect of permanent pacing leads on tricuspid bioprosthetic valve function and regurgitation. Methods Our case focuses on a 62-year-old woman with mechanical mitral and biological tricuspid prosthesis due to rheumatic disease since 2007 and with a PM-DDDR for a postsurgical complete atrioventricular block. A lead was implanted in right atrium while another lead was implanted in the coronary sinus (CS) instead of in the right ventricle following the presence of a biological tricuspid prosthesis. In February 2022, she did a replacement of pacemaker (PM) generator to another hospital due to initial battery depletion. In March she described pain at the device pocket and consequent appearance of pocket infection. For this situation she was admitted to our cardiac department. A transesophageal echocardiography (TEE) was performed and showed normal biventricular size and function (LVEF 55%), normal function of valve prostheses and absence of vegetations both on the valves and atrial lead. Subsequently an angiography was performed and revealed little patency of the anonymous-caval-subclavian left axis. We made a diagnosis of pocket infection and decided to extract leads in March. We proceded through debridement of leads and removal of the PM generator. After placing Spectranetics (Philips) Lead Locking Device n.2 (LLD2) along the 2007 right atrial lead, we removed it through the use of a mechanical extractors (Cook 7-8.5 Fr). Then after placing Spectranetics (Philips)Lead Locking Device E (LLDE), the CS lead was completely removed through the use of a mechanical extractors (Cook 7-8.5 Fr) and specific delivery.The procedure was well tolerated and uneventful. Following the negative result of the post-extraction blood cultures, cultures of lead tips and pocket swab, together with the normalization of inflammation indices (WBC and CRP) and to the end of antibiotic therapy, we decided to reimplant the device.For the presence of valve prostheses and the patient's high infectious risk, we decided to implant a leadless PM. Results At the beginning of April we performed a leadless Micra AV PM implantation through 23-F Micra TPS delivery catheter across a tricuspid bioprosthetic valve in the right ventricular apex instead of the middle septum due to implantation difficulties for the concomitant presence of the bioprosthetic valve. The procedure was well tolerated and uneventful too. She was discharged after 72h in good conditions. Conclusions We present an unusual case of lead extraction for the second infection of the device pocket in a patient with mechanical mitral and biological tricuspid prostheses and a lead in coronary sinus for the presence of biological tricuspid prosthesis. Leadless PM implantation represents a new technology by eliminating the risks connected with the presence of the lead across the bioprosthetic valve.

Outcomes of leadless pacemaker implantation following transvenous lead extraction in high-volume referral centers: Real-world data from a large international registry

Limited data on the real-world safety and efficacy of leadless pacemakers (LPMs) post-transvenous lead extraction (TLE) are available. The purpose of this study was to assess the long-term safety and effectiveness of LPMs following TLE in comparison with LPMs de novo implantation. Consecutive patients who underwent LPM implantation in 12 European centers joining the International LEAdless PacemakEr Registry were enrolled. The primary end point was the comparison of LPM-related complication rate at implantation and during follow-up (FU) between groups. Differences in electrical performance were deemed secondary outcomes. Of the 1179 patients enrolled, 15.6% underwent a previous TLE. During a median FU of 33 (interquartile range 24-47) months, LPM-related major complications and all-cause mortality did not differ between groups (TLE group: 1.6% and 5.4% vs de novo group: 2.2% and 7.8%; P = .785 and P = .288, respectively). Pacing threshold (PT) was higher in the TLE group at implantation and during FU, with very high PT (>2 V@0.24 ms) patients being more represented than in the de novo implantation group (5.4% vs 1.6 %; P = .004). When the LPM was deployed at a different right ventricular (RV) location than the one wherethe previous transvenous RV lead was extracted, a lower proportion of high PT (>1-2 V@0.24 ms) patients at implantation, 1-month FU, and 12-month FU (5.9% vs 18.2%, P = .012; 3.4% vs 12.9%, P = .026; and 4.3% vs 14.5%, P = .037, respectively) was found. LPMs showed a satisfactory safety and efficacy profile after TLE. Better electrical parameters were obtained when LPMs were implanted at a different RV location than the one where the previous transvenous RV lead was extracted.

Leadless pacing – ESC Guidelines and EHRA Position Paper

In 2022 the position paper developed by four scientific societies (EHRA, HRS, LAHRS, APHRS) has been published. Among other, it covers issues related to leadless pacing. Document summaries currently available technology, center and personnel requirements, periprocedural issues. An extremely important part of the document summarises the level of recommendation for leadless pacemaker implantation taking into consideration electrocardiographic indications for permanent pacing including a percentage of ventricular pacing and diffe­rent clinical scenarios.

Accidental coronary artery kinking by leadless pacemaker fixation tine.

We present a case of a 59-year-old woman who presented with a coronary syndrome soon after an uneventful leadless pacemaker (MicraVR™, Medtronic) implantation. A routine postoperative electrocardiogram (ECG) revealed alteration of the baseline ECG (Panel A, left) with appearance of a complete right bundle branch block (RBBB) and ST-segment elevation in V3 (Panel A, middle). She reported intermittent moderate chest pain which worsened in left lateral position. An emergency transthoracic echocardiogram showed minimal pericardial effusion (<0.5 mm) with a normal systolic left ventricular function. A coronary computed tomography angiogram suggested that the septal anchor of the pacemaker partially occluded the distal segment of the left anterior descending (LAD) artery (Panel B). This was associated with enhancement defects on septo-apical and apical segments, consistent with ischaemia. The coronary angiography confirmed the partial LAD kinking in relation to the device anchor which was considered extravascular (Panel C). After patient consent, pacemaker retrieval was successfully performed using a 26Fr Gore DrySeal™ introducer sheath, a 12Fr Cook Performer™ guiding sheath holding an EV3 Amplatz gooseneck Snare of 15 mm. Once the pacemaker was trapped and before applying traction, a 0.14 Asahi FielderXT™ coronary wire was inserted through the lesion, to protect the vessel in case of injury. The coronary integrity was confirmed after device removal (Panel D). The RBBB disappeared 48 h later, leaving a Q wave in lead V3 (Panel A, right). Systematic postoperative ECG is warranted after leadless pacemaker implantation.