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Introduction: Initial data suggest that His Bundle Pacing (HBP) could preserve long‐term cardiac structure and function better than Right Ventricular Pacing (RVP), but evidence is limited. Methods: We studied consecutive patients with baseline ejection fraction (EF) ≥ 50% who underwent HBP attempt, either successful (HBP group) or failed (RVP group). Two‐dimensional (2D) and three‐dimensional (3D) echocardiography were carried out at baseline and after 6 months of ventricular pacing burden > 20%. Results: Among 68 patients, 40 underwent successful HBP, and 28 RVP. The HBP and RVP groups did not differ for age, sex and pacing indication. At baseline, the HBP and RVP groups did not differ for 2D EF (62% vs. 62%), 3D EF (60% vs. 63%), 2D (−19% vs. −19%) and 3D global longitudinal strain (GLS) (−15% vs. −16%). After 6 months, 2D EF (−3.86%) and 3D EF (−5.71%) significantly decreased in the RVP group and did not change in the HBP group (p for interaction.006 and <.001, respectively). 2D GLS (3.08%) and 3D GLS (2.22%) significantly increased in the RVP group, but did not change in the HBP group (p for interaction.013 and <.016, respectively). Pacing induced cardiomyopathy (PICM) (EF drop ≥ 10% and EF < 50%) occurred in 14% (RVP) versus 0% (HBP) of patients (p =.025). Conclusions: Successful HBP was superior to RVP in preserving LV systolic function despite a high ventricular pacing burden, and was less frequently associated with PICM. [ABSTRACT FROM AUTHOR]

Aims Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve outcomes in patients with symptomatic, refractory atrial fibrillation (AF). Superior approach (SA) from the pocket, via the axillary or subclavian vein, has been recently proposed as an alternative to the conventional femoral access (FA) to perform AVJA. In this study, we compare the impact of these alternative approaches on nurse workload (NWL) and patient satisfaction. Methods and results This was a prospective, observational study enrolling consecutive patients undergoing simultaneous CSP and AVJA. Electrophysiology laboratory (EP Lab) NWL was calculated by using a self-developed model. Ward NWL was calculated using the MIDENF® validated scale. Patient satisfaction was collected using the Hospital Consumer Assessment of Healthcare Provider Systems questionnaire. A total of 119 patients were enrolled: in 50, AVJA was primarily attempted with SA, and in 69 with FA. Compared with FA, SA was associated with a lower EP Lab NWL (169.8 ± 26.7 vs. 202.7 ± 38.9 min; P < 0.001) and a lower Ward NWL (474.5 ± 184.8 vs. 808.6 ± 289.9 min; P < 0.001). Multivariate analysis identified SA as an independent predictor of lower EP Lab NWL [hazard ratio (HR) 4.60; P = 0.001] and of lower Ward NWL (HR 45.13; P < 0.001). Compared with FA, SA was associated with a higher patient-reported rating regarding their experience during hospital stay (P = 0.035) and the overall hospital evaluation (P = 0.026). Conclusion In patients undergoing simultaneous CSP and AVJA, the use of an SA for ablation is a valid alternative to conventional FA. Compared with FA, this approach significantly reduces NWL and is associated with greater patient satisfaction. Registration ClinicalTrials.gov : NCT03612635 [ABSTRACT FROM AUTHOR]

Aims: The randomized, double‐blind, placebo‐controlled HOPE‐HF trial assessed the benefit of atrio‐ventricular (AV) delay optimization delivered using His bundle pacing. It recruited patients with left ventricular ejection fraction ≤40%, PR interval ≥200 ms, and baseline QRS ≤140 ms or right bundle branch block. Overall, there was no significant increase in peak oxygen uptake (VO2max) but there was significant improvement in heart failure specific quality of life. In this pre‐specified secondary analysis, we evaluated the impact of baseline PR interval, echocardiographic E‐A fusion, and the magnitude of acute high‐precision haemodynamic response to pacing, on outcomes. Methods and results: All 167 randomized participants underwent measurement of PR interval, acute haemodynamic response at optimized AV delay, and assessment of presence of E‐A fusion. We tested the impact of these baseline parameters using a Bayesian ordinal model on VO2max, quality of life and activity measures. There was strong evidence of a beneficial interaction between the baseline acute haemodynamic response and the blinded benefit of pacing for VO2 (Pr 99.9%), Minnesota Living With Heart Failure (MLWHF) (Pr 99.8%), MLWHF physical limitation score (Pr 98.9%), EQ‐5D visual analogue scale (Pr 99.6%), and exercise time (Pr 99.4%). The baseline PR interval and the presence of baseline E‐A fusion did not have this reliable ability to predict the clinical benefit of pacing over placebo across multiple endpoints. Conclusions: In the HOPE‐HF trial, the acute haemodynamic response to pacing reliably identified patients who obtained clinical benefit. Patients with a long PR interval (≥200 ms) and left ventricular impairment who obtained acute haemodynamic improvement with AV‐optimized His bundle pacing were likely to obtain clinical benefit, consistent across multiple endpoints. Importantly, this gradation can be reliably tested for before randomization, but does require high‐precision AV‐optimized haemodynamic assessment to be performed. [ABSTRACT FROM AUTHOR]

Background: His bundle pacing (HBP) and left bundle branch pacing (LBBP) are emerging therapies for patients with heart failure and conduction disorders, offering potential advantages over traditional pacing methods. These approaches aim to restore physiological conduction and improve cardiac function more effectively. Objective: This study aims to evaluate the efficacy and safety of HBP and LBBP in patients with heart failure and conduction disturbances, comparing these techniques to conventional pacing. Methods: A comprehensive review of recent studies and clinical trials was conducted, focusing on the performance of HBP and LBBP in improving cardiac function, reducing QRS duration, and enhancing overall patient outcomes. The analysis includes data on clinical efficacy, procedural safety, and long-term benefits associated with these pacing modalities. Results: Both HBP and LBBP have demonstrated significant improvements in cardiac function and clinical outcomes compared to conventional pacing. HBP effectively restores physiological conduction with improved synchronization and a reduction in QRS duration. LBBP has shown enhanced left ventricular activation, leading to better overall cardiac performance. Both techniques have been associated with a lower incidence of complications and a higher success rate in achieving optimal pacing thresholds. Conclusions: HBP and LBBP offer promising alternatives to traditional pacing for patients with heart failure and conduction disorders. These advanced pacing strategies provide superior clinical outcomes and improved cardiac function with reduced risk of complications. Further research and clinical trials are needed to fully establish the long-term benefits and safety profiles of these techniques in diverse patient populations. [ABSTRACT FROM AUTHOR]

Background: Ventricular tachycardia (VT) reduces cardiac output through high heart rates, loss of atrioventricular synchrony, and loss of ventricular synchrony. We studied the contribution of each mechanism and explored the potential therapeutic utility of His bundle pacing to improve cardiac output during VT. Methods: Study 1 aimed to improve the understanding of mechanisms of harm during VT (using pacing simulated VT). In 23 patients with left ventricular impairment, we recorded continuous ECG and beat-by-beat blood pressure measurements. We assessed the hemodynamic impact of heart rate and restoration of atrial and biventricular synchrony. Study 2 investigated novel pacing interventions during clinical VT by evaluating the hemodynamic effects of His bundle pacing at 5 bpm above the VT rate in 10 patients. Results: In Study 1, at progressively higher rates of simulated VT, systolic blood pressure declined: at rates of 125, 160, and 190 bpm, -22.2%, -42.0%, and -58.7%, respectively (ANOVA p < 0.0001). Restoring atrial synchrony alone had only a modest beneficial effect on systolic blood pressure (+ 3.6% at 160 bpm, p = 0.2117), restoring biventricular synchrony alone had a greater effect (+ 9.1% at 160 bpm, p = 0.242), and simultaneously restoring both significantly increased systolic blood pressure (+ 31.6% at 160 bpm, p = 0.0003). In Study 2, the mean rate of clinical VT was 143 ± 21 bpm. His bundle pacing increased systolic blood pressure by + 14.2% (p = 0.0023). In 6 of 10 patients, VT terminated with His bundle pacing. Conclusions: Restoring atrial and biventricular synchrony improved hemodynamic function in simulated and clinical VT. Conduction system pacing could improve VT tolerability and treatment. [ABSTRACT FROM AUTHOR]

Aims The application of conduction system pacing (CSP) in clinical practice is growing, and the need for lead extraction will also increase. The data on outcomes and safety of CSP lead extraction are limited. The aim of this study was to assess procedural outcomes and safety of CSP lead removal. Methods and results Forty-seven patients from the EXTRACT Registry with the indication for CSP lead removal were enrolled in the study conducted at the Department of Electrocardiology in Katowice, Poland. Extraction technique, outcomes, safety, and complication were evaluated. Forty-three (91.5%) leads were successfully removed, and 41 (87.2%) were removed with traction only. The dwelling time of 28 extracted leads was longer than 1 year, and the oldest extracted lead was implanted for 89 months. Seven (14.9%) leads were removed from the left bundle branch (LBB) area and 36 from the His bundle (HB). Transient complete atrioventricular block occurred during the procedure in two patients. In 27 out of 31 attempts (87.1%), new CSP leads were implanted: nine (33.3%) HB pacing leads and 18 (66.7%) LBB area pacing leads. Conclusion The CSP lead extraction is safe and feasible with a low complication rate and high rate of CSP lead reimplantation. [ABSTRACT FROM AUTHOR]

With the advancement of pacing technologies, His-Purkinje conduction system pacing (HPCSP) has been increasingly recognized as superior to conventional right ventricular pacing (RVP) and biventricular pacing (BVP). This method is characterized by a series of strategies that either strengthen the native cardiac conduction system or fully preserve physical atrioventricular activation, ensuring optimal clinical outcomes. Treatment with HPCSP is divided into two pacing categories, His bundle pacing (HBP) and left bundle branch pacing (LBBP), and when combined with atrioventricular node ablation (AVNA), can significantly improve left ventricular (LV) function. It effectively prevents tachycardia and regulates ventricular rates, demonstrating its efficacy and safety across different QRS wave complex durations. Therefore, HPCSP combined with AVNA can alleviate symptoms and improve the quality of life in patients with persistent atrial fibrillation (AF) who are unresponsive to multiple radiofrequency ablation, particularly those with concomitant heart failure (HF) who are at risk of further deterioration. As a result, this “pace and ablate” strategy could become a first-line treatment for refractory AF. As a pacing modality, HBP faces challenges in achieving precise localization and tends to increase the pacing threshold. Thus, LBBP has emerged as a novel approach within HPCSP, offering lower thresholds, higher sensing amplitudes, and improved success rates, potentially making it a preferable alternative to HBP. Future large-scale, prospective, and randomized controlled studies are needed to evaluate patient selection and implantation technology, aiming to clarify the differential clinical outcomes between pacing modalities. [ABSTRACT FROM AUTHOR]

Atrioventricular junction ablation (AVJA) together with the implantation of cardiac pacemaker has become a recognized and effective treatment strategy for patients with symptomatic tachysystolic atrial fibrillation that does not respond to heart rate control drug therapy. Left bundle branch pacing (LBBP) is a physiological alternative to right ventricular and biventricular pacing. The aim. To analyze the clinical results of the average duration with the use of LBBP and AVJA. Materials and methods. Over the period from January 2023 to July 2024, LBBP with subsequent AVJA was applied at the National Amosov Institute of Cardiovascular Surgery in 18 patients as a method of treatment of chronic tachysystolic atrial fibrillation to achieve heart rate control. Results. Mid-term results (at least 1 month) could be monitored in 15 out of 18 patients (84%); in the other three (16%) patients the time between pacemaker implantation and AVJA was too short. The mean period from pacemaker implantation to control examination was 5.07 ± 2.79 months (minimum period 1 month, maximum 12 months). During the period from implantation and ablation to the control observation in the study group, it was possible to observe an increase in left ventricular ejection fraction from 39.12 ± 10.56% to 46.38 ± 7.09%, p = 0.035; decrease in the values of end-diastolic volume from 184.22 ± 76.76 to 167.85 ± 36.93 ml, p = 0.074; decrease in the right ventricular pressure from 43.07 ± 8.29 to 34.38 ± 4.78 mm Hg, p = 0.013. It was also possible to observe a decrease in the left bundle branch capture thresholds from 1.27 ± 0.58 to 0.7 ± 0.39 V at 0.4 ms, p = 0.016; and a decrease in the average LBBP endocardial lead resistance from 638 ± 172.83 to 529.4 ± 120.15 Ohm, p = 0.012. Conclusions. Implantation of the LBBP pacemaker and AVJA was not associated with the occurrence of complications both in the intraoperative and postoperative periods, as well as in the remote period of the average duration in the studied group. The use of this approach in patients with chronic atrial fibrillation made it possible in a series of consecutive patients to improve the systolic function of the left ventricle, to reduce the values of the end-diastolic volume of the left ventricle and the right ventricular pressure at optimal pacing parameters.

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

In patients with narrow QRS complex, both ventricular and biventricular pacing is associated with increased cardiac morbidity and mortality. This risk is not decreased by ventricular pacing avoidance algorithms, which cause nonphysiologic atrioventricular (AV) delays. This study aimed to report outcomes in patients with narrow QRS complex when the paced complex is in normal range and physiologic AV delays are programmed. In 196 patients with QRS duration of 92 ± 10 ms, permanent pacing was done at the site of the His bundle electrogram. The pacemakers were then programmed to maintain physiologic AV delays and to increase heart rates in response to exercise. Patients received usual care and were observed for 3 years. The paced complex exhibited a delta wave, and the ventricular activation time, QRS axis, and lead I voltage remained in normal range. Physiologic programming resulted in His bundle pacing burden of 92%. In patients with decreased ejection fraction, there was significant improvement in left ventricular function, left ventricular dilation, and mitral regurgitation (P <.003). In patients with normal ejection fraction, left ventricular function remained normal without new valvular abnormalities. The 3-year all-cause mortality was 10%, and there was no increase in heart failure admissions. In patients with narrow QRS complex, when paced QRS morphology is maintained in normal range and AV dyssynchrony is avoided, His bundle pacing is associated with low all-cause mortality and improvement in abnormal echocardiographic parameters. The paced QRS morphology and physiologic AV delays may be important factors to evaluate in future trials of conduction system pacing. [Display omitted] [ABSTRACT FROM AUTHOR]

The feasibility of the conduction system pacing combined with atrioventricular node ablation was demonstrated in patients with atrial fibrillation in whom rate control can’t be achieved with medication and heart failure.

The current gold standard in device therapy for advanced heart failure (HF), which has been firmly established in HF management for more than 25 years, is classical biventricular pacing (BiV-CRT). In the last decade, a new pacing modality called conduction system pacing (CSP) has emerged as a variant for advanced cardiac device therapy. It provides pacing with preserved intrinsic cardiac activation by direct stimulation of the specific cardiac conduction system. The term CSP integrates the modalities of HIS bundle pacing (HBP) and left bundle branch area pacing (LBBAP), both of which have provided convincing data in smaller randomized and big non-randomized studies for the prevention of pacemaker-induced cardiomyopathy and for providing effective cardiac resynchronization therapy in patients with classical CRT-indication (primary approach or after failed CRT). Recent American guidelines proposed the term "cardiac physiological pacing" (CPP), which summarizes CSP including left ventricular septal pacing (LVSP), a technical variant of LBBAP together with classical BiV-CRT. The terms HOT-CRT (HIS-optimized CRT) and LOT-CRT (LBBP-optimized CRT) describe hybrid technologies that combine CSP with an additional coronary-sinus electrode, which is sometimes useful in patients with advanced HF and diffuse interventricular conduction delay. If CSP continues providing promising data that can be confirmed in big, randomized trials, it is likely to become the new gold standard for patients with an expected high percentage of pacing (>20%), possibly also for cardiac resynchronization therapy. CSP is a sophisticated new treatment option that has the potential to raise the term "cardiac resynchronization therapy" to a new level. The aim of this review is to provide basic technical, anatomical, and functional knowledge of these new pacemaker techniques in order to facilitate the understanding of the different modalities, as well as to provide an up-to-date overview of the existing randomized and non-randomized evidence, particularly in direct comparison to right ventricular and classical biventricular pacing. [ABSTRACT FROM AUTHOR]

Purpose of the review: Cardiac pacing has evolved in recent years currently culminating in the specific stimulation of the cardiac conduction system (conduction system pacing, CSP). This review aims to provide a comprehensive overview of the available literature on CSP, focusing on a critical classification of studies comparing CSP with standard treatment in the two fields of pacing for bradycardia and cardiac resynchronization therapy in patients with heart failure. The article will also elaborate specific benefits and limitations associated with CSP modalities of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP). Recent findings: Based on a growing number of observational studies for different indications of pacing therapy, both CSP modalities investigated are advantageous over standard treatment in terms of narrowing the paced QRS complex and preserving or improving left ventricular systolic function. Less consistent evidence exists with regard to the improvement of heart failure-related rehospitalization rates or mortality, and effect sizes vary between HBP and LBBAP. LBBAP is superior over HBP in terms of lead measurements and procedural duration. With regard to all reported outcomes, evidence from large scale randomized controlled clinical trials (RCT) is still scarce. Summary: CSP has the potential to sustainably improve patient care in cardiac pacing therapy if patients are appropriately selected and limitations are considered. With this review, we offer not only a summary of existing data, but also an outlook on probable future developments in the field, as well as a detailed summary of upcoming RCTs that provide insights into how the journey of CSP continues. [ABSTRACT FROM AUTHOR]

Ventricular backup leads may be considered in selected patients with His bundle pacing (HBP), but it remains unknown to what extent this is useful. A total of 184 HBP patients were studied. At last follow-up, 147 (79.9%) patients retained His bundle capture at programmed output. His bundle pacing lead revision was performed in 5/36 (13.9%) patients without a backup lead and in 3/148 (2.0%) patients with a backup lead (P = 0.008). One patient without a backup lead had syncope due to atrial oversensing. Thus, implantation of ventricular backup leads may avoid lead revision and adverse events in selected HBP patients. [ABSTRACT FROM AUTHOR]

Traditional right ventricular pacing (RVP) has been linked to the deterioration of both left ventricular diastolic and systolic function. This worsening often culminates in elevated rates of hospitalization due to heart failure, an increased risk of atrial fibrillation, and increased morbidity. While biventricular pacing (BVP) has demonstrated clinical and echocardiographic improvements in patients afflicted with heart failure and left bundle branch block, it has also encountered significant challenges such as a notable portion of non-responders and procedural failures attributed to anatomical complexities. In recent times, the interest has shifted towards conduction system pacing, initially, His bundle pacing, and more recently, left bundle branch area pacing, which are seen as promising alternatives to established methods. In contrast to other approaches, conduction system pacing offers the advantage of fostering more physiological and harmonized ventricular activation by directly stimulating the His–Purkinje network. This direct pacing results in a more synchronized systolic and diastolic function of the left ventricle compared with RVP and BVP. Of particular note is the capacity of conduction system pacing to yield a shorter QRS, conserve left ventricular ejection fraction, and reduce rates of mitral and tricuspid regurgitation when compared with RVP. The efficacy of conduction system pacing has also been found to have better clinical and echocardiographic improvement than BVP in patients requiring cardiac resynchronization. This review will delve into myocardial function in conduction system pacing compared with that in RVP and BVP. [ABSTRACT FROM AUTHOR]

Background: His bundle pacing (HBP) engaged electrical activation of both ventricles by stimulating the His‐Purkinje network, which could avoid marked ventricles dyssynchrony. The lead was given three to five clockwise rotations at the site with the His potential to anchor the interventricular septum. In 2018, the Multicenter His Bundle Pacing Collaborative Working Group recommended that the His bundle capture threshold should be lower than 2.5 V/1 ms in non‐pacing‐dependent patients, and pacing‐dependent patients should have a lower adjacent ventricular capture threshold as self‐backup. Therefore, to avoid safety issues such as loss of capture caused by increased threshold, we believe that more stringent criteria should be adopted in patients with atrioventricular block (AVB). In previous studies, the connection cable needed to be disconnected during the screwing. When the procedure was finished, the performer found that the patients with His bundle injury could obtain a lower threshold than those without His bundle injury. Although no studies of new bundle branch block (BBB) or AVB by the acute His bundle injury was reported. However, It is worrying that the damage of His bundle seems random during the procedure. How to balance avoiding severe injury with a lower capture threshold? At present, we report a case of light His injury and lower His capture threshold under continuous intracardiac electrocardiogram monitoring. [ABSTRACT FROM AUTHOR]

Conduction system pacing (CSP) has the potential to achieve physiological-paced activation by pacing the ventricular conduction system. Before CSP is adopted in standard clinical practice, large, randomised, and multi-centre trials are required to investigate CSP safety and efficacy compared to standard biventricular pacing (BVP). Furthermore, there are unanswered questions about pacing thresholds required to achieve optimal pacing delivery while preventing device battery draining, and about which patient groups are more likely to benefit from CSP rather than BVP. In silico studies have been increasingly used to investigate mechanisms underlying changes in cardiac function in response to pathologies and treatment. In the context of CSP, they have been used to improve our understanding of conduction system capture to optimise CSP delivery and battery life, and noninvasively compare different pacing methods on different patient groups. In this review, we discuss the in silico studies published to date investigating different aspects of CSP delivery. [ABSTRACT FROM AUTHOR]

The document titled "Expert Opinion on Conduction System Pacing Implantation" provides expert insights and guidelines for the implementation of conduction system pacing (CSP). CSP offers a more physiologically sound alternative to conventional right ventricular pacing, and it is increasingly utilized not only for pacing but also for cardiac resynchronization therapy. In this article, we aim to encapsulate the EHRA Clinical Consensus Statement on CSP implantation, offering healthcare practitioners a standardized procedure while underscoring key recommendations. [ABSTRACT FROM AUTHOR]

Background: Left bundle branch area pacing (LBBAP) and His bundle pacing (HBP) are the main strategies to achieve conduction system pacing (CSP), but only observational studies with few patients have compared the two pacing strategies, sometimes with unclear results given the different definitions of the feasibility and safety outcomes. Therefore, we conducted a meta-analysis aiming to compare the success and complications of LBBAP versus HBP. Methods: We systematically searched the electronic databases for studies published from inception to March 22, 2023, and focusing on LBBAP versus HBP. The study endpoints were CSP success rate, device-related complications, CSP lead-related complications and non-CSP lead-related complications. Results: Fifteen observational studies enrolling 2491 patients met the inclusion criteria. LBBAP led to a significant increase in procedural success [91.1% vs 80.9%; RR: 1.15 (95% CI: 1.08–1.22); p < 0.00001] with a significantly lower complication rate [1.8% vs 5.2%; RR: 0.48 (95% CI: 0.29–0.78); p = 0.003], lead-related complications [1.1% vs 4.3%; RR: 0.38 (95% CI: 0.21–0.72); p = 0.003] and lead failure/deactivation [0.2% vs 3.9%; RR: 0.16 (95% CI: 0.07–0.35); p < 0.00001] than HBP. No significant differences were found between CSP lead dislodgement and non-CSP lead-related complications. Conclusion: This meta-analysis of observational studies showed a higher success rate of LBBAP compared to HBP with a lower incidence of complications. [ABSTRACT FROM AUTHOR]

Abstract Background His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) emerge as better alternatives to right ventricular apical pacing (RVAP) in patients with bradycardia requiring permanent cardiac pacing. We aimed to compare the clinical outcomes of LBBAP, HBP, and RVAP in Japanese patients with bradycardia. Methods A total of 424 patients who underwent successful pacemaker implantation (HBP, n = 53; LBBAP, n = 75; and RVAP, n = 296) were retrospectively enrolled in this study. The primary study endpoint was the cumulative incidence of heart failure hospitalization (HFH) during the follow‐up. Results The success rate for implantation was higher in the LBBAP group than in the HBP group (94.9% and 81.5%, respectively). Capture threshold increase >1V during the follow‐up occurred in the HBP and RVAP groups (9.4% and 5.1%, respectively), while it did not in the LBBAP group. The cumulative incidence of HFH was significantly lower in the LBBAP group than the RVAP (adjusted hazard ratio, 0.12 [95% confidence interval: 0.02–0.86]; p = .034); it did not differ between the HBP and RVAP groups (adjusted hazard ratio, 0.48 [95% confidence interval: 0.17–1.34]; p = .16). Advanced age, mean percent right ventricular pacing (per 10% increase), left ventricular ejection fraction

[Display omitted] [ABSTRACT FROM AUTHOR]

The anatomy of the His‐Purkinje system has been studied, yet there remains a knowledge gap regarding the impact of His bundle pacing and its electrocardiographic implications. This case report highlights the presence of His‐Purkinje system pathology without apparent clues on the surface electrocardiogram (EKG). By observing identical QRS morphology with varying HV intervals resulting from different pacing outputs, we demonstrate the presence of an electrical propagation block within the His bundle. [ABSTRACT FROM AUTHOR]

Objectives: Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve the outcomes in patients with symptomatic, refractory atrial fibrillation (AF). In this setting, AVJA can be performed simultaneously with implantation or in a second procedure a few weeks after implantation. Comparison data on these two alternative strategies are lacking. Methods: A prospective, multicentre, observational study enrolled consecutive patients with symptomatic, refractory AF undergoing CSP and AVJA performed in a single procedure or in two separate procedures. Data on the long-term outcomes and healthcare resource utilization were prospectively collected. Results: A total of 147 patients were enrolled: for 105 patients, CSP implantation and AVJA were performed simultaneously (concomitant AVJA); in 42, AVJA was performed in a second procedure, with a mean of 28.8 ± 19.3 days from implantation (delayed AVJA). After a mean follow-up of 12 months, the rate of procedure-related complications was similar in both groups (3.8% vs. 2.4%; p = 0.666). Concomitant AVJA was associated with a lower number of procedure-related hospitalizations per patient (1.0 ± 0.1 vs. 2.0 ± 0.3; p < 0.001) and with a lower number of hospital treatment days per patient (4.7 ± 1.8 vs. 7.4 ± 1.9; p < 0.001). Conclusions: Concomitant AVJA resulted as being as safe as delayed AVJA and was associated with a lower utilization of healthcare resources. [ABSTRACT FROM AUTHOR]

Background: The effect of His bundle pacing (HBP) on the incidence of new-onset atrial fibrillation (AF) after pacemaker implantation (PMI) for atrioventricular conduction disturbance (AVCD) remains unknown. We compared the incidence of new-onset atrial high-rate episode (AHRE) in conventional right ventricular (RV) septum pacing (RVSP) and His bundle pacing (HBP) after PMI for AVCD. Methods: One hundred and four consecutive patients who underwent dual chamber PMI for AVCD in our hospital were screened. Thirty-five patients with mitral or aortic valve disease, history of open-heart surgery, prior AF, subclinical AF, cumulative ventricular pacing percentage < 90%, and RV lead revision were excluded, and 69 patients were effectively enrolled in this study. The primary endpoint was new-onset AHRE within the follow-up period. New-onset AHRE was defined as an atrial high-rate episode that occurred 3 months after PMI and lasted for > 6 min at an atrial heart rate > 190 bpm. RV leads were placed in the His bundle region and RV septum region in 22 and 47 patients, respectively. The mean follow-up period was 539 ± 218 days. The follow-up period was 2 years after PMI or until the new-onset AHRE occurred. Results: The incidence of new-onset AHRE was lower in the HBP group than in the RVSP group (11% vs. 43%, p = 0.01). Multivariate analysis in the Cox regression hazard model showed that HBP had a significantly lower risk of new-onset AHRE compared with RVSP (HR = 0.21; 95% confidence interval 0.04–0.78, p = 0.02). Conclusion: The incidence of new-onset AHRE was significantly less in HBP compared to RVSP during the 2-year follow-up period after pacemaker implantation in AVCD patients with RV pacing dependence. [ABSTRACT FROM AUTHOR]

Introduction: His bundle pacing (HBP) is suitable for 80% of patients with any indication for permanent pacemaker implantation, with a clinical benefit compared to right ventricular pacing (RVP). Although complications and mortality related to RVP are widely reported in the literature, data on HBP are limited. This study aimed to analyze HBP complications and outcomes in the short-term (up to 30 days) and long-term (up to the following 24 months) follow-up (F/U). Materials and Methods: The study includes 373 patients aged ≥ 18, enrolled from October 2015 to May 2019 in a single-center HBP prospective registry conducted in the Department of Electrocardiology, Upper Silesian Medical Centre of the Medical University of Silesia in Katowice, Poland. Mortality and HBP complications were used as end-points: during hospitalization and up to 30 days (short-term F/U), and for each F/U point—six months, 12 months, and 24 months after the procedure (long-term F/U). Results: Successful HBP was achieved in 252 patients (68%), with an increasing success rate during consecutive years: 57% in 2015–2016 and 73% in 2017–2019. Complications were found in 8.4% of patients (21/252) in short-term F/U and 5.8% (13/224), 5.5% (11/201), and 6.9% (12/174) at six months, 12 months, and 24 months, respectively. There were no deaths during the first 30 days. However, 26 patients (10.3%) died within 24 months. A left ventricular ejection fraction (LVEF) ≤ 34% was the only independent predictor of all-cause mortality or any major complication in the 24-month F/U. Conclusions: This single-center study reported a low risk of mortality and complications associated with HBP at the short-term F/U. However, during the long-term F/U, we observed a higher but acceptable risk of major complications, with a lower LVEF being an independent predictor of the composite end-point of all-cause mortality or any major complication. [ABSTRACT FROM AUTHOR]

It is axiomatic that the chances of achieving accurate capture of the conduction axis and its fascicles will be optimized by equally accurate knowledge of the relationship of the components to the recognizable cardiac landmarks, and we find it surprising that acknowledged experts should continue to use drawings that fall short in terms of anatomical accuracy. The accuracy achieved by Sunao Tawara (1906) in showing the location of the atrioventricular conduction axis is little short of astounding. Our purpose in bringing this to current attention is to question the need of the experts to have produced such inaccurate representations, since the findings of Tawara have been extensively endorsed in very recent years. The recent studies do no more than point to the amazing accuracy of the initial account of Tawara. At the same time, we draw attention to the findings described in the middle of the 20th century by Ivan Mahaim (1947). These observations have tended to be ignored in recent accounts. They are, perhaps, of equal significance to those seeking specifically to pace the left fascicles of the branching atrioventricular bundle. [ABSTRACT FROM AUTHOR]

Abstract Background Fluoroscopy is conventionally performed for cardiac implantable electronic device (CIED) therapy and carries radiation drawback for both patients and medical workers. Recently, zero to minimal fluoroscopy (ZMF) approach is introduced to reduce radiation exposure of fluoroscopy. This study compares the feasibility and safety of ZMF approach to fluoroscopy for CIEDs therapy in adults. Method A systematic literature search was conducted on PubMed, ScienceDirect, and Web of Science in March 2023. All observational or experimental studies comparing ZMF approach to fluoroscopy for adult CIEDs therapy were included. Reviews, case report/series, animal studies, and non‐English articles were excluded. The success rate, procedural time, fluoroscopy time, radiation dose, and complications rate were compared for each approach. Results Seven articles for permanent and three articles for temporary CIEDs were included for analysis. The success rate of ZMF for permanent CIEDs was similar to fluoroscopy method (OR: 0.77, 95% CI: 0.33–4.15). The procedural time of ZMF was similar to fluoroscopy for both permanent and temporary CIEDs (standardized mean difference [SMD]: 0.10, 95% CI: −0.35 to 0.55 and SMD: −0.71, 95% CI: −1.87–0.44, respectively). However, ZMF approach markedly reduced the fluoroscopy time and radiation exposure for permanent CIEDs (SMD: −1.80, 95% CI: −2.49 to −1.12 and SMD: −1.26, 95% CI: −2.24 to −0.29). The complication rate was similar for permanent CIEDs (OR: 1.08, 95% CI: 0.41–2.84), yet lowered for temporary CIEDs (OR: 0.34, 95% CI: 0.20–0.59). Conclusion ZMF had similar success rate, procedural time, and sum complication rate for permanent CIEDs implantation with a significant reduction of fluoroscopy time and radiation exposure.

Introduction. Right ventricular myocardial pacing leads to asynchronous contraction of the left ventricle (LV) and can impair its contractility over time. Stimulation of the conduction system of the heart ensures physiological activation of the ventricles. The aim. To visualize the pattern of propagation of the electrical front on the activation map of the LV endocardium during conduction system pacing and during right ventricular myocardial pacing. Materials and methods. In two patients with the conduction system pacing, who were operated at the National Amosov Institute of Cardiovascular Surgery, invasive LV activation mapping was performed on various options of cardiac pacing using the EnSite Precision TM navigation system. One patient with complete atrioventricular block had nonselective His bundle pacing. The second patient had dilated cardiomyopathy and indications for cardiac resynchronization therapy and ablation of the atrioventricular junction due to chronic tachyform of atrial fibrillation. After an unsuccessful attempt to place LV lead in coronary sinus, a lead for left bundle branch pacing was implanted. Different activation maps of the LV endocardium were built in two patients with two types of cardiac pacing: right ventricular myocardial pacing and cardiac conduction system pacing. Results. The total LV endocardial activation time was significantly different in the two studied patients with different pacing options. In a patient with non-selective stimulation of His bundle, the total LV endocardial activation time was 43 ms (QRS width 126 ms, the interval from the stimulus to the peak of the R wave in lead V6 78 ms). After switching to right ventricular myocardial pacing with a decrease in the pacing amplitude, the total LV endocardial activation time prolonged to 90 ms (QRS width 165 ms, the interval from the stimulus to the peak of the R wave in lead V6 117 ms). In a patient with left bundle branch pacing, total LV endocardial activation time was 51 ms (QRS width 160 ms, the interval from the stimulus to the peak of the R wave in lead V6 66 ms). With switching exclusively to right ventricular pacing the total LV endocardial activation time prolonged to 93 ms (stimulated QRS width 180 ms). At the same time, the activation pattern of the LV endocardium was significantly different, since the right ventricular lead was located closer to the apex. Conclusions. Conduction system pacing provides rapid physiological LV activation and potentially avoids the negative consequences of asynchronous slow ventricular activation during right ventricular pacing.

Background: His bundle pacing (HBP) and left bundle branch pacing (LBBP) are emerging therapies for patients with heart failure and conduction disorders, offering potential advantages over traditional pacing methods. These approaches aim to restore physiological conduction and improve cardiac function more effectively. Objective: This study aims to evaluate the efficacy and safety of HBP and LBBP in patients with heart failure and conduction disturbances, comparing these techniques to conventional pacing. Methods: A comprehensive review of recent studies and clinical trials was conducted, focusing on the performance of HBP and LBBP in improving cardiac function, reducing QRS duration, and enhancing overall patient outcomes. The analysis includes data on clinical efficacy, procedural safety, and long-term benefits associated with these pacing modalities. Results: Both HBP and LBBP have demonstrated significant improvements in cardiac function and clinical outcomes compared to conventional pacing. HBP effectively restores physiological conduction with improved synchronization and a reduction in QRS duration. LBBP has shown enhanced left ventricular activation, leading to better overall cardiac performance. Both techniques have been associated with a lower incidence of complications and a higher success rate in achieving optimal pacing thresholds. Conclusions: HBP and LBBP offer promising alternatives to traditional pacing for patients with heart failure and conduction disorders. These advanced pacing strategies provide superior clinical outcomes and improved cardiac function with reduced risk of complications. Further research and clinical trials are needed to fully establish the long-term benefits and safety profiles of these techniques in diverse patient populations.

The His‐bundle has several locations from which conduction system pacing can be achieved. Some locations offer better sensing, thresholds and paced QRS durations. Existing techniques to aid repositioning of an already deployed, but sub‐optimally placed lead, include either simple memory of the initial lead position combined with its observation on an x‐ray review screen or utilizing an additional vascular access and pacing lead with the first lead serving as a real‐time marker (Two‐lead technique). We describe a novel, readily available, cost‐efficient, imaging‐based approach to assist in the re‐positioning of a pacing lead for His‐bundle pacing (the Image Overlay Technique). [ABSTRACT FROM AUTHOR]

Background: Fluoroscopy is conventionally performed for cardiac implantable electronic device (CIED) therapy and carries radiation drawback for both patients and medical workers. Recently, zero to minimal fluoroscopy (ZMF) approach is introduced to reduce radiation exposure of fluoroscopy. This study compares the feasibility and safety of ZMF approach to fluoroscopy for CIEDs therapy in adults. Method: A systematic literature search was conducted on PubMed, ScienceDirect, and Web of Science in March 2023. All observational or experimental studies comparing ZMF approach to fluoroscopy for adult CIEDs therapy were included. Reviews, case report/series, animal studies, and non‐English articles were excluded. The success rate, procedural time, fluoroscopy time, radiation dose, and complications rate were compared for each approach. Results: Seven articles for permanent and three articles for temporary CIEDs were included for analysis. The success rate of ZMF for permanent CIEDs was similar to fluoroscopy method (OR: 0.77, 95% CI: 0.33–4.15). The procedural time of ZMF was similar to fluoroscopy for both permanent and temporary CIEDs (standardized mean difference [SMD]: 0.10, 95% CI: −0.35 to 0.55 and SMD: −0.71, 95% CI: −1.87–0.44, respectively). However, ZMF approach markedly reduced the fluoroscopy time and radiation exposure for permanent CIEDs (SMD: −1.80, 95% CI: −2.49 to −1.12 and SMD: −1.26, 95% CI: −2.24 to −0.29). The complication rate was similar for permanent CIEDs (OR: 1.08, 95% CI: 0.41–2.84), yet lowered for temporary CIEDs (OR: 0.34, 95% CI: 0.20–0.59). Conclusion: ZMF had similar success rate, procedural time, and sum complication rate for permanent CIEDs implantation with a significant reduction of fluoroscopy time and radiation exposure. [ABSTRACT FROM AUTHOR]

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Conduction system pacing is an alternative practice to conventional right ventricular apical pacing. It is a method that maintains physiologic ventricular activation, based on a correct pathophysiological basis, in which the pacing lead bypasses the lesion of the electrical fibers and the electrical impulse transmits through the intact adjacent conduction system. For this reason, it might be reasonably characterized by the term "electrical bypass" compared to the coronary artery bypass in revascularization therapy. In this review, reference is made to the sequence of events in which conventional right ventricular pacing may cause adverse outcomes. Furthermore, there is a reference to alternative strategies and pacing sites. Interest focuses on the modalities for which there are data from the literature, namely for the right ventricular (RV) septal pacing, the His bundle pacing (HBP), and the left bundle branch pacing (LBBP). A more extensive reference is about the HBP, for which there are the most updated data. We analyze the considerations that limit HBP-wide application in three axes, and we also present the data for the implantation and follow-up of these patients. The indications with their most important studies to date are then described in detail, not only in their undoubtedly positive findings but also in their weak aspects, because of which this pacing mode has not yet received a strong recommendation for implementation. Finally, there is a report on LBBP, focusing mainly on its points of differentiation from HBP. [ABSTRACT FROM AUTHOR]

Background: Conduction system pacing (CSP) and atrioventricular junction ablation (AVJA) improve outcomes in patients with symptomatic, refractory atrial fibrillation (AF). Superior approach (SA) from the pocket via axillary or subclavian vein has been proposed as an alternative to the conventional femoral venous access (FA) to perform AVJA. Objective: To assess the feasibility and safety of SA for AVJA performed simultaneously with CSP, and to compare this approach with FA. Methods: A prospective, observational study, enrolling consecutive patients with symptomatic, refractory AF undergoing simultaneous CSP and AVJA. Results: A total of 107 patients were enrolled: in 50, AVJA was primarily attempted with SA, in 69 from FA. AVJA with SA was successful in 38 patients (76.0%), while in 12 patients, a subsequent FA was required. AVJA from FA was successful in 68 patients (98.5%), while in one patient, a left‐sided approach via femoral artery was required. Compared with FA, SA was associated with a significantly longer duration of ablation (238.0 ± 218.2 vs. 161.9 ± 181.9 s; p =.035), a significantly shorter procedure time (28.1 ± 19.8 vs. 19.8 ± 16.8 min; p =.018), an earlier ambulation (2.7 ± 3.2 vs. 19.8 ± 0.1 h; p <.001), and an earlier discharge from procedure completion (24.0 ± 2.7 vs. 27.1 ± 5.1 h; p <.001). After a median follow‐up of 12 months, the rate of complications was similar in the two groups (2.0% in SA, 4.3% in FA; p =.483). Conclusion: Simultaneous CSP and AVJA with SA is feasible, with a safety profile similar to FA. Compared to FA, this approach reduces the procedure times and allows earlier ambulation and discharge. [ABSTRACT FROM AUTHOR]

Left bundle branch block (LBBB) pattern on the electrocardiogram includes patients with both complete conduction block in the His-Purkinje system as well as nonspecific left ventricular conduction delay without discrete block. The purpose of this study was to characterize electrocardiographic morphological features of LBBB patterns in patients with (1) LBBB after transcatheter aortic valve replacement (TAVR) and (2) LBBB correctable by conduction system pacing (CSP). Consecutive patients with post-TAVR (n = 123) or CSP-correctable LBBB (n = 58) from 2 centers were included in this retrospective evaluation. QRS durations as well as detailed morphological features, including notching and slurring, of QRS complexes in leads I, aVL, V 1 , V 2 , V 5 , and V 6 and in all 3 inferior leads were recorded. The mean age of the entire cohort was 78.3 ± 10.1 years, with 48% of the cohort being male (87/181). In the CSP-correctable group (n = 58), 14 (24.1%) underwent His-bundle pacing and 44 (75.9%) left bundle branch area pacing. A total of 17 of 181 (9.4%) of the combined cohort failed to completely meet the Strauss criteria. QRS morphology in lead V 1 /V 2 was always either rS or QS, and there were no q/Q waves noted in lead V 5 /V 6. Although dominant R waves were seen in leads I and aVL of 176 of 181 (97.2%), q/Q waves were present in only 21 of 181 (11.6%). Importantly, notched or slurred QRS complexes were identified in at least 1 lead of 4 leads I, aVL, V 5 , and V 6 in 181 of 181 (100%). Strauss criteria and QRS notching are highly prevalent in LBBB after TAVR and in LBBB correctable by CSP. [ABSTRACT FROM AUTHOR]

For patients with congenital heart disease (CHD), chronic ventricular pacing may lead to progressive cardiomyopathy owing to electromechanical dyssynchrony. Cardiac conduction system pacing (CSP) has been proposed as a physiologic pacing strategy—directly engaging the His–Purkinje system and preserving electromechanical synchrony. CSP may be indicated for a wide variety of children and adults with CHD and has emerged as an important tool in the armamentarium for cardiac implantable electronic device operators. This review provides the rationale, background, and supportive evidence for CSP in patients with CHD and discusses implant strategies and outcomes in the context of dominant ventricular morphologic categories. [ABSTRACT FROM AUTHOR]

Aims The compatibility of cardiac pacing with the presence of a subcutaneous implantable cardioverter-defibrillator (S-ICD) has been investigated, but S-ICD screening test results have not been compared among different pacing sites. The objective was to compare S-ICD screening results among different cardiac pacing sites and to assess the electrocardiographic predictors of success. Methods and results This prospective single-centre study conducted automated S-ICD screening in 102 carriers of cardiac pacing devices in conduction system (CSP), biventricular (BVP), right ventricular outflow tract (RVOT), or right ventricular apex (RVA) pacing sites. The study included 102 patients: 40 with CSP (20 left bundle pacing and 20 His bundle pacing), 21 with BVP, and 20 and 21 with RVOT and RVA pacing, respectively. The percentage of positive screenings was significantly higher for CSP (97.5%) than for the other patient groups (BVP 71.4%, RVOT 70%, and RVA 19%). In multivariate analysis, positive screening was associated with a narrower QRS (OR 0.95 [0.92–0.98] P = 0.001) and higher R/T ratio in precordial leads (1.76 [1.18–2.61]). Conclusion A higher S-ICD eligibility rate of cardiac pacing device carriers was obtained in CSP than in conventional pacing (RVA or RVOT) or BVP. The presence of narrower paced QRS width and paced corrected QT interval and of higher R/T ratio in precordial and limb leads are electrocardiographic predictors of a positive response to screening. [ABSTRACT FROM AUTHOR]

Abstract The anatomy of the His‐Purkinje system has been studied, yet there remains a knowledge gap regarding the impact of His bundle pacing and its electrocardiographic implications. This case report highlights the presence of His‐Purkinje system pathology without apparent clues on the surface electrocardiogram (EKG). By observing identical QRS morphology with varying HV intervals resulting from different pacing outputs, we demonstrate the presence of an electrical propagation block within the His bundle.

The document titled "Expert Opinion on Conduction System Pacing Implantation" provides expert insights and guidelines for the implementation of conduction system pacing (CSP). CSP offers a more physiologically sound alternative to conventional right ventricular pacing, and it is increasingly utilized not only for pacing but also for cardiac resynchronization therapy. In this article, we aim to encapsulate the EHRA Clinical Consensus Statement on CSP implantation, offering healthcare practitioners a standardized procedure while underscoring key recommendations

Evaluation of conduction intervals to predict success of resynchronization in biventricular pacing(BiVP) or Conduction System Pacing(CSP) is not spread in clinical practice. A right ventricle-to-left ventricle intrinsic conduction interval (RVs–LVs) > 70 ms or prolonged RVpaced – LVs(RVp-LVs)interval can predict Cardiac Resynchronization Therapy (CRT)response.This paper describes a case of cardiac resynchronization guided by spontaneous and paced interventricular conduction delays (IVCD) obtained in BiVP that led to changing intraoperative approach. A strategy for cardiac resynchronization based on the CSP/BiVP approach according to the IVCD could represent a viable and reliable solution to obtain a narrow paced QRS and to improve the CRT response.

Abstract Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing‐induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre‐procedure evaluation and preparation, implant procedure management, follow‐up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Background Metabolic disorder is noted for pacing‐induced cardiomyopathy. The benefits of His bundle pacing over right ventricular (RV) pacing in preventing pacing‐induced cardiomyopathy from a metabolic perspective are yet to be fully understood. Method and Results Three pig groups were established for this study: sham control, RV pacing (RV pacing for 6 months), and His pacing (RV pacing for 6 months, followed by His bundle pacing for 3 months). Complete atrioventricular block was created in the last 2 groups. Left ventricular function and dyssynchrony were assessed via echocardiography, while proteins linked to metabolism, endoplasmic reticulum stress, and inflammation in left ventricular myocardium were examined. The RV pacing group had significantly more left ventricular mechanical dyssynchrony compared with the other groups. The RV pacing group exhibited triglyceride and diacylglycerol accumulation in cardiomyocytes and higher expression of binding immunoglobulin protein and tumor necrosis factor‐α than the other groups. Additionally, the expression of CD36 was activated, while the expression of hormone‐sensitive lipase was downregulated in the RV pacing group compared with the His pacing and sham control groups. Furthermore, the expressions of GLUT4 and pyruvate dehydrogenase were higher in the RV pacing group than the sham control and His pacing groups. Notably, the abnormal fatty acid and glucose metabolic pathways in the left ventricular myocardium during RV pacing could be corrected by His bundle pacing. Conclusions His bundle pacing can mitigate the abnormal metabolism disorders, endoplasmic reticulum stress, and inflammation induced during RV pacing and may contribute to the superiority of conduction system pacing over RV pacing in reducing heart failure hospitalization.

Objective: We aimed to evaluate the feasibility and safety of his-bundle pacing (HBP) and left bundle branch pacing (LBBP) in patients with hypertrophic cardiomyopathy (HCM) and heart failure (HF). Methods: Patients with HF and interventricular septal thickness (IVST) ≥ 13 mm resulted from HCM, who accepted conduction system pacing (CSP) with a percentage of ventricular pacing > 40% from May 2018 to April 2022 were consecutively enrolled in our center. LBBP was preferred and HBP was the alternative therapy unless IVST ≥ 16 mm or LBBP failed, whereas LBBP would be the alternative therapy if HBP failed in patients with IVST ≥ 16 mm. All patients were followed up for at least one year. Data including clinical, echocardiographic parameters and electrocardiogram measurements, were collected and evaluated in patients with and without left ventricular ejection fraction (LVEF)

BACKGROUND: Pacing is the most effective and dependable method for treating complete atrioventricular block (AVB). OBJECTIVE: The purpose of this study is to investigate the use of His bundle pacing (HBP) in patients with atrioventricular block. METHODS: Patients who underwent HBP or right ventricular pacing (RVP) were enrolled and divided into two groups: the HBP group and the RVP group, respectively. We compared baseline clinical data, fluoroscopy duration, operation duration, pacing electrode parameters during the operation or follow-up, baseline QRS duration, and pacing QRS duration. RESULTS: HBP was attempted in 48 patients and was successful in 34 patients who were included in the HBP group. In addition, 30 RVP patients were included in the RVP group. Fluoroscopy duration and operation duration were significantly longer in the HBP group compared to the RVP group. Compared to the RVP group, the HBP group had a higher pacing threshold, a lower R wave amplitude, and a shorter pacing QRS duration. At 6 months of follow-up, the pacing threshold remained higher, the R wave amplitude was significantly lower, and the end-diastolic diameter of the left ventricle was smaller in the HBP group. CONCLUSION: HBP was safe and effective for atrioventricular block despite the longer fluoroscopy and operation duration in the HBP group when compared to the RVP group. [ABSTRACT FROM AUTHOR]

His bundle pacing (HBP) has become popular in recent years as a more physiological alternative to conventional right ventricular pacing. Implantation requires 12‑lead ECG during surgery, which is not readily available in a standard operating room. Often but not always HBP is performed in an electrophysiology lab. EASI is a reduced lead system which enables derived 12‑lead ECG. EASI derived 12‑lead ECGs on modern tablet computers offer a more mobile and lightweight ECG solution which does not obstruct fluoroscopy during implantation. This case series aims to compare standard 12‑lead ECG to EASI derived 12‑lead ECG in patients undergoing HBP implantation. A total of 11 patients received permanent HBP guided only by fluoroscopy, a pacing system analyzer (Medtronic CareLink SmartSync Device Manager) and EASI derived 12‑lead ECG (CardioSecur Pro). During the first postoperative device interrogation HBP criteria, as defined in the EHRA consensus paper on conduction system pacing, were evaluated with the EASI derived system as well as a standard 12‑lead ECG and compared to each other. There was perfect agreement with regards to these criteria which lead to identical conclusions in all cases. HBP implantation can be performed with EASI derived 12‑lead ECG instead of conventional 12‑lead ECG. Criteria for discriminating between selective His bundle, non-selective His bundle or myocardial capture alone are clearly visible in the EASI derived ECG leading to the same conclusion when compared to standard 12‑lead ECG. Compared to a conventional 12‑lead ECG the EASI system offers a leaner setup with less visual obstruction on fluoroscopy. [ABSTRACT FROM AUTHOR]

Background: “Ablate and pace” strategy is a reasonable treatment option in refractory atrial fibrillation (AF) when sinus rhythm (SR) cannot be achieved with catheter ablation or pharmacological therapy. Atrioventricular node ablation (AVNA) combined with conduction system pacing (CSP), with left bundle branch pacing (LBBP) or His bundle pacing (HBP), is gaining recognition since it offers the most physiological activation of the left ventricle. However, the incidence of conversion to SR after AVNA with CSP is not known. The purpose of the investigation was to determine the incidence of spontaneous conversion to SR and its predicting factors in patients undergoing CSP and AVNA. Methods: Consecutive refractory symptomatic AF patients undergoing AVNA with CSP at our institution between June 2018 and December 2022 were retrospectively analyzed. Twelve lead electrocardiogram (ECG) recordings were analyzed at each outpatient follow-up visit. Echocardiographic and clinical parameters were assessed at baseline and six months after the implantation. Results: Sixty-eight patients (male 42.6%, age 71 ± 8 years, left ventricular ejection fraction 40 ± 15%) were included. Thirty-seven patients (54.4%) received HBP and 31 (45.6%) LBBP. During follow-up, spontaneous conversion to SR was registered in 6 patients (8.8%); 3 in the HBP group and 3 in the LBBP group. Baseline characteristics of patients who converted to SR did not differ from non-sinus rhythm (NSR) patients except for left atrial volume index (LAVI), which was significantly smaller in the SR group (45 mL/m² (41–51) vs. 60 mL/m² (52–75); p = 0.002). Multiple regression model confirmed an inverse association between LAVI and conversion to SR even after considering other clinically relevant covariates (odds ratio 1.273, p = 0.028). At follow-up, LAVI did not change in any group (SR: p = 0.345; NSR: p = 0.508). Improvement in New York Heart Association (NYHA) class was comparable in both groups. Conclusions: Spontaneous conversion to SR after AVNA combined with CSP is not uncommon, especially in patients with smaller left atria. Further studies are warranted to clarify which patients should be considered for initial dual-chamber device implantation to provide atrio-ventricular synchrony in case of SR restoration. [ABSTRACT FROM AUTHOR]

Background or Purpose: His bundle pacing (HBP) is the most physiological form of ventricular pacing. Few prospective studies have analyzed lead localization using imaging techniques and its relationship with electrical parameters and capture patterns. The objective of this study is to examine the correlation between electrical parameters and lead localization using three-dimensional transthoracic echocardiography (3D TTE). Methods: This single-center, prospective, nonrandomized clinical research study (January 2018 to June 2020) included patients with an indication of permanent pacing, in whom 3D TTE was performed to define lead localization as supravalvular or subvalvular. Results: A total of 92 patients were included: 56.5% of leads were supravalvular, and 43.5% were subvalvular, which resembles previous anatomic descriptions of autopsied hearts of His bundle localization within the triangle of Koch (ToK). R-wave sensing was higher when the His lead was localized subvalvular instead of supravalvular. His lead localization was not associated with HBP threshold or impedance differences, nor with the two different HBP patterns of capture, or with the ability of HBP to correct baseline BBB. The thresholds remained stable during follow-up visits, regardless of His lead localization. Higher R-wave sensing was observed during follow-up than at baseline, mainly in the subvalvular His leads. However, lead impedances in both positions decreased during follow-up. Conclusions: Lead localization in relation to the tricuspid valve did not influence the electrical performance of HBPs. Wide anatomical variations of the His bundle within the ToK explain our findings, reinforcing the idea that the technique for HBP should be fundamentally guided by electrophysiological and not anatomical parameters. [ABSTRACT FROM AUTHOR]