Performance of an Automatic Capture Confirmation Algorithm in a Large Cohort of Pacemaker Patients with Left Bundle Branch Area Pacing

The electromechanical dyssynchrony associated with right ventricular pacing (RVP) has been found to have adverse impact on clinical outcomes. Several studies have shown that left bundle branch area pacing (LBBAP) has superior pacing parameters compared with RVP. We aimed to assess the difference in ventricular electromechanical synchrony and investigate the risk of atrial high-rate episodes (AHREs) in patients with LBBAP and RVP. We consecutively identified 40 patients with atrioventricular block and no prior atrial fibrillation. They were divided according to the ventricular pacing sites: the LBBAP group and the RVP group (including the right ventricular apical pacing (RVA) group and the right side ventricular septal pacing (RVS) group). Evaluation of ventricular electromechanical synchrony was implemented using electrocardiogram and two-dimensional speckle tracking echocardiography (2D-STE). AHRE was defined as event with an atrial frequency of ≥176 bpm lasting for ≥6 min recorded by pacemakers during follow-up. The paced QRS duration of the LBBAP group was significantly shorter than that of the other two groups: LBBAP 113.56 ± 9.66 ms vs. RVA 164.73 ± 14.49 ms, p < 0.001; LBBAP 113.56 ± 9.66 ms vs. RVS 148.23 ± 17.3 ms, p < 0.001. The LBBAP group showed shorter maximum difference (TDmax), and standard deviation (SD) of the time to peak systolic strain among the 18 left ventricular segments, and time of septal-to-posterior wall motion delay (SPWMD) compared with the RVA group (TDmax, 87.56 ± 56.01 ms vs. 189.85 ± 91.88 ms, p = 0.001; SD, 25.40 ± 14.61 ms vs. 67.13 ± 27.40 ms, p < 0.001; SPWMD, 28.75 ± 21.89 ms vs. 99.09 ± 46.56 ms, p < 0.001) and the RVS group (TDmax, 87.56 ± 56.01 ms vs. 156.46 ± 55.54 ms, p = 0.003; SD, 25.40 ± 14.61 ms vs. 49.02 ± 17.85 ms, p = 0.001; SPWMD, 28.75 ± 21.89 ms vs. 91.54 ± 26.67 ms, p < 0.001). The interventricular mechanical delay (IVMD) was shorter in the LBBAP group compared with the RVA group (-5.38 ± 9.31 ms vs. 44.82 ± 16.42 ms, p < 0.001) and the RVS group (-5.38 ± 9.31 ms vs. 25.31 ± 21.36 ms, p < 0.001). Comparing the RVA group and the RVS group, the paced QRS duration and IVMD were significantly shorter in the RVS group (QRS duration, 164.73 ± 14.49 ms vs. 148.23 ± 17.3 ms, p = 0.02; IVMD, 44.82 ± 16.42 ms vs. 25.31 ± 21.36 ms, p = 0.022). During follow-up, 2/16 (12.5%) LBBAP patients, 4/11 (36.4%) RVA patients, and 8/13 (61.5%) RVS patients had recorded novel AHREs. LBBAP was proven to be independently associated with decreased risk of AHREs than RVP (log-rank p = 0.043). LBBAP generates narrower paced QRS and better intro-left ventricular and biventricular contraction synchronization compared with traditional RVP. LBBAP was associated with a decreased risk of AHREs compared with RVP.

Background: Long-term right ventricular pacing (RVP) can cause electrical and mechanical dyssynchrony, resulting in adverse outcomes. Recently, left bundle branch area pacing (LBBAP) has emerged as a physiological pacing modality and is considered a promising alternative. To date, the long-term outcomes of LBBAP compared with RVP, particularly with respect to sex differences, remain unclear. Methods: Between January 2017 and July 2024, 1211 patients who underwent de novo pacemaker implantation were enrolled and categorized into RVP (n = 789) and LBBAP (n = 422). The primary outcome was a composite of all-cause mortality, heart failure hospitalization (HFH), and pacing-induced cardiomyopathy (PICM). Propensity score matching (PSM) was employed to minimize the selection bias and achieve comparability among the study population. A post hoc power analysis based on the observed effect size and sample size showed a power of 80%, confirming sufficient sensitivity to detect group differences. Results: After PSM, 764 patients were analyzed. The mean age of the patients was 74.6 ± 10.5 years in RVP and 74.5 ± 9.8 years in LBBAP, respectively, and 52.3% patients were male. Patients with LBBAP had a lower incidence of the primary outcome (8.6% vs. 24.6%, p < 0.001), HFH (2.6% vs. 13.6%, p < 0.001), and all-cause mortality (6.5% vs. 13.9%, p < 0.001) compared with RVP. There were no significant differences in the clinical outcomes, including the primary outcome, HFH and all-cause mortality, between the sexes in the group with either RVP or LBBAP. However, during a 2-year follow-up period for survival analysis, male patients with LBBAP had a significant lower incidence of all the endpoints, whereas female patients with LBBAP had a lower incidence of HFH [HR 0.14 (95% CI 0.06-0.32), p = 0.001] compared with those with RVP. Conclusions: Regardless of sex, patients with LBBAP had a lower risk of poor clinical outcomes, including HFH and all-cause mortality, compared to those with RVP. Moreover, compared with RVP, LBBAP decreased the risks of all the major endpoints in male patients and the risk of HFH particularly in female patients. Further research is needed to establish the sex-specific responses to LBBAP.

Comparing Left Bundle Branch Area vs Right-Ventricular Septal Pacing in High-Degree Conduction Disease After Transcatheter Aortic Valve Replacement: Randomized Trial Study Protocol

Background Right ventricular placement of the OmniaSecure defibrillation lead has demonstrated high defibrillation success, low occurrence of lead-related major complications and high predicted reliability. With the advent of left bundle branch area pacing (LBBAP) as a more physiologic option for therapeutic delivery of pacing, LBBAP has emerged as a potentially more desirable option for pacing in the ICD population. Purpose To understand the safety and performance of the OmniaSecure defibrillation lead when placed in the LBBA in ICD and CRT indicated patients. Methods The Lead Evaluation for Defibrillation and Reliability in LBBAP (LEADR LBBAP) clinical trial is a global, prospective, non-randomized, multi-center study to evaluate the OmniaSecure defibrillation lead in the LBBAP position. Enrolled patients are indicated for de novo implantation of a primary or secondary prevention ICD (LBBAP-ICD) or left bundle branch area pacing-optimized CRT-D (LOT-CRT-D). LOT-CRT-D patients required a coronary sinus lead for LV pacing. At least 300 patients are required for enrollment with a minimum of 150 LOT-CRT-D implant attempts. Per study protocol, LBBAP includes deep septal pacing. The primary efficacy objective is defibrillation efficacy at implant exceeding a pre-specified threshold of 88% in at least 160 patients. The defibrillation protocol aligned to standard of care testing with a maximum of six inductions and troubleshooting and/or lead repositioning in-between. Defibrillation success was defined as termination of first sustained shockable ventricular arrhythmia (SSVA) episode with 18J or 10J safety margin or termination of additional induced SSVA episodes with a 10J safety margin. The primary safety objective is to demonstrate the lead-related major complication rate at 3 months post-implant. Database snapshot was February 12, 2025. Results As of data snapshot, a total of 191 patients met the criteria for LBBAP implant attempt (age: 66.3±12.0 years; 31.0% female). The physician-reported LBBAP implant success per protocol was 95.8% (n=183; n=104 LBBAP-ICD; n=79 LOT-CRT-D). Defibrillation testing was performed in 162 patients with a protocol success rate of 100%. In 98.1% there was no need for repositioning or troubleshooting as the first induced SSVA was successfully treated. During available follow up (116.7±37.4 days; 62 patients with 3-month follow-up), there was one major lead related complication (high RV threshold) 92 days after implant that resulted in replacement with a non-study lead. There were no lead fractures or deaths related to system and/or procedure. Conclusion The LEADR LBBAP clinical trial is the first large clinical trial to prospectively assess the safety and efficacy of a novel defibrillation lead implanted for LBBAP in a large cohort of ICD and CRT-D indicated patients. These results demonstrate procedural-related safety and efficacy of the OmniaSecure lead when placed for LBBAP. Long-term follow-up is ongoing.

BackgroundConduction system pacing (CSP) using His Bundle Pacing (HBP) and Left Bundle Branch Area Pacing (LBAP) is an evolving alternative to traditional right ventricular pacing (RVP), promising better physiological outcomes. This study evaluates the safety, feasibility, and performance of HBP and LBAP with Medtronic SelectSecure 3830 leads.MethodsWe conducted a single-center retrospective analysis of 490 patients undergoing HBP or LBAP. The study assessed implant success rates, pacing thresholds, device longevity, and complication rates over an average follow-up of 28 months for HBP and 14 months for LBAP.ResultsThe implantation success rate was 85% for HBP and 97.4% for LBAP. LBAP demonstrated lower and more stable pacing thresholds, with initial values of 0.8V at 0.5 ms rising slightly to 0.9V at 0.5 ms, and fewer device revisions compared to HBP, whose initial pacing threshold of 1.3V at 0.8ms increased to 1.68 V at 0.7ms. Complications were minimal and similar across both groups. The need for fewer device revisions and potential for prolonged device life highlighted LBAP as potentially more cost-effective. Cardiac function measured by LVEF remained stable across both groups.ConclusionsBoth HBP and LBAP are safe and feasible with comparable safety profiles. LBAP may offer advantages in terms of stability, fewer revisions, and extended device longevity. The study underscores the need for further research into optimal lead positioning and long-term outcomes of CSP, particularly for LBAP.Graphical

This study aims to assess whether left bundle branch area pacing (LBBAP) can result in favorable clinical and echocardiographic outcomes among patients with persistent atrial fibrillation (PeAF). We prospectively enrolled consecutive patients with PeAF if they required ventricular pacing and had left ventricular ejection fraction (LVEF)>35%. During the same period, two experienced operators performed LBBAP and right ventricular pacing (RVP). All-cause death and heart failure hospitalization (HFH) were routinely followed after procedure. The primary outcome was the composite endpoints of all-cause death or HFH. LBBAP was successful in 49 of 52 patients (94.2%), whereas 44 patients received RVP. During a mean follow-up of 13.9±7.0 months, LBBAP group presented with higher ventricular pacing percentage (80% vs. 50.9%, p=.04) and narrower paced QRS duration (117.2±18.8ms vs. 151.8±13.7ms, p<.001) than RVP group. The primary endpoint was slightly reduced in LBBAP group than RVP without reaching statistical significance (7.7% vs. 11.4%, p=.48). Compared with baseline, we observed significant changes in LVEF (+0.7% vs. -2.2%, p=.007) and left atrial diameter (-1.63mm vs. +1.23mm, p=.011) between LBBAP and RVP. Our results indicate possible effect of LBBAP on reverse remodeling of left atrium and a trend towards favorable clinical outcomes in patients with PeAF requiring high burden of ventricular pacing when compared with RVP.

This study aimed to determine the ideal pacing site in children by comparing the postoperative ventricular synchrony in children with left bundle branch area pacing and those with right ventricular septal pacing. This retrospective study included children with complete atrioventricular block who underwent permanent pacemaker implantation from March 2019 to August 2021. Patients were grouped according to their ventricular pacing site, the left bundle branch area pacing group and the right ventricular septal pacing group. Two-dimensional speckle tracking echocardiography was used to evaluate the ventricular synchrony. Forty-eight children (median age, 2.7 years; interquartile range, 1.7-4.6 years) were included. The paced QRS duration in the left bundle branch area pacing group was significantly narrower than that in the right ventricular septal pacing group (100.2 ± 9.3 versus 115.4 ± 15.1 ms, p = 0.001). The median follow-up duration was 1.5 years (interquartile range, 1-2 years). At the last follow-up, the average capture threshold of the ventricular electrode in the left bundle branch area pacing group was lower than that in the right ventricular septal pacing group (0.79 ± 0.18 versus 1.20 ± 0.56 V, p = 0.008). The left ventricular intraventricular synchrony parameters in the left bundle branch area pacing group were better than those in the right ventricular septal pacing group (e.g. standard deviation of the time to peak longitudinal strain, 37.4 ± 4.3 versus 46.6 ± 8.2 ms, p = 0.000). The average interventricular mechanical delay time in the left bundle branch area pacing group was significantly shorter than that in the right ventricular septal pacing group (36.4 ± 14.2 versus 52.5 ± 22.7 ms, p = 0.016). Compared with right ventricular septal pacing, left bundle branch area pacing in children produces a narrower QRS duration and better pacing and ventricular synchrony parameters postoperatively.

PO-01-028 LEAD HELIX FAILS TO RETRACT DURING LEFT BUNDLE BRANCH AREA PACING IMPLANT

Chronic right ventricular (RV) pacing can exacerbate heart failure in patients with a low left ventricular ejection fraction (LVEF). Left bundle branch area pacing (LBBAP) has emerged as a novel physiological pacing technique; however, information remains limited on its use among patients with a low EF. This study investigated the safety and short-term clinical outcomes of LBBAP among patients with impaired left ventricular (LV) function. This retrospective analysis of pacemakers at Chosun University Hospital, South Korea, included all patients with impaired LV function (EF<50%) who underwent pacemaker implantation for atrioventricular blockage from 2019-2022. Clinical characteristics, 12-lead electrocardiography findings, echocardiography findings, and laboratory parameters were evaluated. Composite outcomes were defined as all-cause mortality, cardiac death, and hospitalization due to heart failure during the 6-month follow-up. Altogether 57 patients (25 men; mean age, 77.4±10.8 y; LVEF, 41.5±3.8%) were divided into LBBAP (n=16), biventricular pacing (BVP; n=16), and conventional RV pacing (RVP; n=25) groups. In the LBBAP group, the mean paced QRS duration (pQRSd) was narrower (119.5±14.7 vs. 140.2±14.3 vs. 163.2±13.9; p<0.001) and cardiac troponin I level was elevated post-pacing (1.14±1.29 vs. 0.20±0.29 vs. 0.24±0.51, p=0.001). Lead parameters were stable. One patient was hospitalized, and four died (one patient each from heart failure admission, myocardial infarction, unexplained death, and pneumonia in RVP vs. one from intracerebral hemorrhage in BVP) during the follow-up period. In conclusion, LBBAP is feasible in patients with impaired LV function without acute or significant complications and provides a remarkably narrower pQRSd with a stable pacing threshold.

Background Left bundle branch area pacing (LBBaP) is a novel pacing modality which provides physiological synchronisation of both the ventricles. However, its use and adoption requires the presence of a standardised electrophysiological (EP) system with 12 lead ECG to show left bundle branch area capture. Purpose The aim of the study was to assess the feasibility and outcomes of using the conventional treadmill test (TMT) machine 12 lead ECG system and modified V1 and V6 leads connected to the pacing system analyser (PSA) to demonstrate conduction system capture during left bundle branch area pacing (LBBaP). Methods LBBaP was attempted by a single operator in a mixed cohort of patients at peripheral hospitals lacking the standardised EP system. The presence of LBB area capture was tested with the aid of the 12 lead ECG system connected to the standard TMT machine (1). Conduction system capture was also assessed using modified V1 and V6 leads connected to the PSA for measurement of V6 left ventricular activation time (LVAT)(2) . The baseline clinical, procedural, pacing, electrocardiographic parameters, echocardiographic response (&amp;gt; 10% improvement in ejection fraction {EF}) and clinical response to LBBaP were assessed. Results LBBaP was attempted in 19 patients and was successful in 18 patients (94.7%). Patient characteristics include age 66.7 +/- 11.47 years, female 47.37%, male 52.63%, ischaemic cardiomyopathy 10.52% and non-ischaemic cardiomyopathy 5.26% .The mean baseline EF and QRS duration was 45%+/-14% and 130.18 +/-10.45 milliseconds(ms) respectively. LBBaP threshold was 0.59 +/-0.168 volts and R wave amplitude was 12+/-3.5 millimetres , which remained stable during the mean follow up of 15.9 +/-13.67 months. The mean fluoroscopic duration was 11.57 +/-2.58 minutes and procedural time was 108.78+/-29.20 minutes. LBBaP resulted in impressive narrowing of the QRS duration to 102.39 +/-10.55 ms (p&amp;lt;0.001) with LVAT of 68.94 +/-9.94 ms. LVEF improved in the patients with cardiomyopathy from 33.4 +/- 5.77 % to 48.2+/-12.37 % (p=0.028) .Clinical and echocardiographic response was noted in 87.5% of patients with cardiomyopathy. Conclusion The 12 lead ECG system with the standardised TMT machine in conjunction with the modified V1 and V6 leads connected to the PSA is a feasible alternative to the EP system to perform successful left bundle branch area pacing.ECG leads connected during LBBapClinical profile of patients

Introduction Atrioventricular node ablation (AVNA) with permanent pacing is an effective treatment of symptomatic atrial fibrillation (AF). Permanent right ventricular pacing is associated with cardiac dyssynchrony, which can worsen heart failure (HF) symptoms. Left bundle branch area pacing (LBBAP) is a recent pacing technique, more physiologic and less associated with cardiac dyssynchrony. Purpose To evaluate feasibility, safety and outcomes at 6 months of AVNA associated with LBBAP in patients with symptomatic AF. Methods In this retrospective monocentric study, we included all consecutive patients treated with AVNA procedure and LBBAP. Procedures characteristics, clinical follow-up, electrical and echographic data at baseline and 6 months were studied and compared to the data of a matched cohort (1:1) of patients who received an AVNA procedure with conventional pacing between March 2010 and February 2023. Results 75 AVNA procedures and LBBAP were studied. The success rate of AVNA was 98.7% at first ablation without any complications, especially no lead dislodgement or threshold rise. Pacing electrical parameters at implant were good, and stable at 6 months follow-up, with no threshold rise. At 6 months, 4 (5%) patients were hospitalized for heart failure and 1 (1.3%) was deceased. Patients had a significative improvement in NYHA class, palpitations symptoms, and left ventricular ejection fraction (LVEF) (p ≤ 0.0001 for all). After matching with a cohort of patients with AVNA and conventional pacing (n=68), patients with LBBAP had a significantly better improvement of LVEF (+5.27±9.62% versus -0.48±14%; p = 0.01), and a lower rate of a composite endpoint (all cause death and hospitalization for HF) (HR 0.34, 95%CI: 0.1-1.06; p = 0.064). Conclusions AVNA with LBBAP in patients with symptomatic AF was feasible and safe. Complication rate and adverse outcomes at 6 months were similar to AVNA with conventional pacing, and LVEF improvement was significantly greater.Matched populationsOutcomes at 6 months

Is left bundle branch area pacing the optimal pacing strategy for bradyarrhythmia with preserved ejection fraction? A network meta-analysis.

Background Left bundle branch area pacing (LBBAP) has emerged as a promising approach to cardiac physiologic pacing. However, the mechanical stress and fracture risk has not been studied for stylet-driven leads implanted in the left bundle branch area (LBBA). Purpose The main purpose of this study was to evaluate the change in curvature during a cardiac cycle when a stylet-driven lead with a rigid distal end was implanted in LBBA and to identify any increased risk of conductor fracture for the LBBAP lead compared to those implanted at the His bundle (HB), traditional right atrium (RA) and right ventricle (RV) locations. Methods A high-resolution, four-dimensional human beating heart model was utilized for simulating the stress on the lead. The bending stiffness of lead body segments was measured with 3-pts bending test and the values were assigned to the finite element model. The curvature change of lead body during one cardiac cycle was measured. The safety factor of lead conductors was calculated using the curvature measurements, the conductor’s endurance limit, and the ultimate stress of the material (MP35N). A higher safety factor indicates better lead durability and lower risk of fracture. A parametric study was also performed to investigate how additional implant factors impact the safety factor of LBBAP leads: lead insertion angle, implant depth, degree of slack, and implant location (Figure 1). Results A total of 8 implant scenarios for LBBAP were defined and tested using the combination of the implant factors described above. Two RV implanted locations were tested: RV apex and RV apical septum. One HBP and one RA implant location were tested. The region with maximum change in curvature for LBBAP lead was at 0-10 mm proximal to the ring electrode (Figure 2A). The maximum change in curvature on the lead body for LBBAP, HBP, RV, and RA implants were: 0.022±0.005 (n=8), 0.033 (n=1), 0.036±0.002 (n=2), and 0.024 mm-1 (n=1), respectively (Figure 2B). The safety factor for the lead conductors for LBBAP, HBP, RV, and RA implants were 5.57±1.35 (n=8), 3.48 (n=1), 4.62±0.04 (n=2), and 4.65 (n=1), respectively (Figure 2C). The highest safety factor among all implant locations was 7.63, corresponding to a LBBAP implant scenario with mid-septum location, a 45 degree lead insertion angle towards apex, 7.5 mm lead depth in the septum, and low lead slack. HBP had the lowest safety factor among all implant locations. Conclusion The stylet-driven lead with a rigid distal end implanted at the left bundle branch area does not introduce any further risk of fracture compared to the HBP or traditional RA/RV implant locations in this computational modeling study.Fig 1: LBBAP implants testedFig 2: Lead curvature and safety factor

Background A higher right ventricular (RV) pacing burden in those with permanent pacemakers results in accelerated pacing induced cardiomyopathy, in addition to increased incidence of heart failure and mortality [1–3]. This process may necessitate upgrade to a biventricular system in time, as the cardiomyopathy progresses. Physiological conduction system pacing targets such as His-bundle pacing (HBP) or Left Bundle Branch Area Pacing (LBBAP) have been shown to generate comparatively narrower QRS complexes and thus mitigate this cardiomyopathy development [4,5]. The 2021 ESC guidelines have a class 2b indication for consideration of HBP as an alternative to RV pacing in those with AV block and left ventricular ejection fraction &amp;gt;40%, who are anticipated to have &amp;gt;20% ventricular pacing burden [6]. Purpose To retrospectively identify ECG, echocardiographic, permanent pacemaker (PPM) setting and patient factors associated with high RV pacing burden that may aid selection of those who may benefit from conduction system pacing (CSP). Methods We retrospectively identified 300 consecutive patients who underwent cardiac implantable electronic device insertion in our Electrophysiology Lab from the years 2017–2018. We excluded patients who underwent generator replacements, in addition to those who had biventricular devices or implantable cardioverter defibrillators inserted. We collated ECG, echo, past medical history and pacing data for each patient over a three-year follow up period. Data were analysed using SPSS v.26. Results 160 patients met inclusion criteria. Those with an RV pacing burden &amp;gt;20% were categorised group one (n=85) and those with &amp;lt;20% in group two (n=75). Baseline characteristics of these two groups are compared in Table 1 and Table 2. Our analysis showed that significant differences between these groups included a lower mean HR (Table 1) (55.1±17.8 vs 57.63±17.4) with a more prolonged PR interval (225.7ms ± 8.34 vs. 188.6ms ± 6.62) or atrial fibrillation/flutter (AF/AFL) on admission ECG. There were more males with a greater mean age (High Ventricular Paced (VP) = 76.6 years ± 8.4 vs Low VP = 71.23 years ± 12.3) in the higher VP group, and they demonstrated more incidence of dilated RA/RV on echo (Enlarged RA = 30.5%; Enlarged RV = 23.6% vs 10% and 8.4% respectively). There were significant differences in PPM indications and setting between groups (Table 2), with the higher VP groups having PPM inserted for persistent high-grade AV block (CHB = 31.5% vs 4.9% and Mobitz 2 = 9.6% vs 0%) and had less MVP mode activated (Mode switch algorithm = 13.3% vs 71%). Conclusion Our data suggests that those with persistent high grade AV block such as Mobitz 2 or CHB should be considered for CSP. Other considerations include older age, male sex, dilated RV/RA, prolonged PR, lower intrinsic HR or AF/AFL on admission ECG. PPM mode switching settings to reduce RV pacing burden should be utilised where possible. Funding Acknowledgement Type of funding sources: None.

Left bundle branch area pacing is a recent technique gaining rapid acceptance due to its broader target area and excellent electrical parameters. The aim of this study was to demonstrate the feasibility of left bundle branch area pacing in children and share short-term results. A retrospective study conducted at a single centre between December 2021 and April 2024 involved 19 children who underwent left bundle branch area pacing using Select Secure leads. The study included echocardiographic evaluations, pacing parameters, and follow-up outcomes. The cohort comprised 10 males and 9 females. Median age was seven years (range 2-18), and median weight was 38 kg (range 13-56). All patients had complete atrioventricular block, with seven having isolated congenital complete atrioventricular block and 12 postoperative complete atrioventricular block. In nine patients, transitioning from epicardial to endocardial pacing resulted in ventricular dysfunction due to chronic right ventricular pacing. The remaining patients received left bundle branch area pacing initially. One patient underwent implantation in a septal position close to the left bundle due to left bundle branch area pacing infeasibility. The median post-procedure QRS duration was 92 msec (range 80-117). Median R wave amplitude, threshold, and impedance values were 14.7 mV (range 13.3-16.8), 0.7 mV (range 0.5-1.1), and 728 ohms (range 640-762), respectively. Atrioventricular (DDD mode) leads were implanted in 10 patients, and ventricular leads (VVIR mode) were implanted in nine patients. Median fluoroscopy dose was 18.7 mGy (13.5-34.52). Left bundle branch area pacing can be safely conducted in paediatric patients exhibiting a narrow QRS duration and stable pacing parameters.