Search Results (56)

Right ventricular apex (RVA) pacing has historically been the default approach for cardiac pacing; however, it is associated with the development of progressive left ventricular dysfunction and heart failure (HF), particularly in patients with high pacing burdens. While advances in device programming and modern algorithms have sought to mitigate these effects, preserving physiological activation has proven to be more critical than reducing ventricular pacing. Conduction system pacing (CSP) techniques—namely, His-bundle pacing (HBP) and particularly left bundle branch area pacing (LBBAP)—have emerged as superior alternatives, enabling improved left ventricular function and reduced rates of pacing-induced cardiomyopathy (PICM). Nevertheless, despite the clinical advantages of these procedures over RVA, they face limitations including variable implantation success rates, increased pacing thresholds and lead revision rates, technical challenges, and occasional procedure prolongation. Thus, while CSP approaches represent the future of physiological pacing, RVA pacing continues to provide a necessary and reliable option in the current clinical practice. Full article

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. Full article

Background and Objectives: The role of biventricular pacing (BVP) is less well-established in patients with heart failure with reduced ejection fraction (HFrEF) without left bundle branch block (LBBB). Conduction system pacing (CSP) has gained significant traction and may provide a safe and more physiological alternative to BVP in these patients. A few small studies studying this question have reported conflicting results. This meta-analysis aims to compare procedural and clinical outcomes between CSP and BVP in this group. Materials and Methods: An online literature search was systematically conducted to retrieve studies comparing CSP and BVP in HFrEF patients with non-LBBB. Four studies with 461 patients were included. Results: Implant-derived paced QRS duration was significantly shorter (mean difference [MD] −19.7 ms, 95% confidence interval [CI] −36.2 to −3.3, p = 0.0355) with CSP. Echocardiographic response with significantly greater improvement in left ventricular ejection fraction (MD 5.6%, 95% CI 3.1 to 8.0, p = 0.0106) was also observed with CSP. There were no statistically significant differences in clinical outcomes such as all-cause mortality (relative risk [RR] 0.53, 95% CI 0.18 to 1.60, p = 0.133) and heart failure hospitalization (RR 0.54, 95% CI 0.19 to 1.56, p = 0.129). Conclusions: This meta-analysis suggests that CSP may have better electrical synchrony and echocardiographic response compared to BVP in HFrEF patients with non-LBBB. Further randomized studies with longer follow-up may be required to elucidate potential benefits in clinical outcomes. Full article

Background/Objectives: Although cardiac resynchronization therapy (CRT) plays an established role in the management of heart failure, a significant proportion of patients do not respond despite appropriate candidate selection. The optimization of CRT pacing is one strategy to enhance response. Fusion pacing algorithms aim to synchronize intrinsic right ventricular (RV) conduction with paced left ventricular (LV) activation, resulting in a more physiological ventricular depolarization pattern. This approach may improve electrical synchrony and enhance left ventricular contraction compared to conventional simultaneous biventricular pacing. The aim of this study was to compare the acute, beat-to-beat effects of standard biventricular pacing versus fusion pacing on myocardial function, using both conventional and speckle-tracking echocardiography in heart failure patients with left bundle branch block (LBBB). Methods: In total, 27 heart failure patients (21 men and 6 women) with reduced ejection fraction (EF < 35%), left bundle branch block (QRS > 150 ms), and newly implanted CRT-D systems (Abbott) underwent echocardiographic assessment immediately after device implantation. Echocardiographic parameters—including left atrial strain, left ventricular strain, TAPSE, mitral and tricuspid valve function, and cardiac output—were measured at 5 min intervals under three different pacing conditions: pacing off, simultaneous biventricular pacing, and fusion pacing using Abbott’s SyncAV^® algorithm. Results: In our study, CRT led to a significant shortening of the QRS duration from 169 ± 19 ms at baseline to 131 ± 17 ms with standard biventricular pacing, and further to 118 ± 16 ms with fusion pacing (p < 0.05). Despite the electrical improvement, no significant changes were observed in global longitudinal strain (GLS: −9.15 vs. −9.39 vs. −9.13; p = NS), left ventricular stroke volume (67.5 mL vs. 68.4 mL vs. 68.5 mL; p = NS), or left atrial parameters including strain, area, and ejection fraction. However, fusion pacing was associated with more homogeneous segmental strain patterns, improved aortic valve closure time, and enhanced right ventricular function as reflected by tissue Doppler-derived S’. Conclusions: Immediate QRS narrowing observed in CRT patients—particularly with fusion pacing optimization—is associated with a more homogeneous pattern of left ventricular contractility and improvements in selected measures of mechanical synchrony. However, these acute electrical changes do not translate into immediate improvements in stroke volume, global LV strain, or left atrial function. Longer-term follow-up is needed to determine whether the electrical benefits of CRT, especially with fusion pacing, lead to meaningful hemodynamic improvements. Full article

Background/Objectives:Pacing treatment of bradyarrhythmias is both to reduce symptoms and to prevent syncope and sudden cardiac death. The aim of our study was to analyze left bundle branch area pacing (LBBAP) in the prevention of new-onset AF and the improvement of echocardiographic parameters in patients with mildly reduced left ventricular ejection fraction (LVEF) compared to patients with bradyarrhythmias but preserved LVEF who underwent mid-septal right ventricular pacing. Methods: This research was structured as a retrospective observational cohort study that included 186 patients with LBBAP and 186 patients with RVP, enrolled for 3 years until March 2024 with a follow-up time of 1 year. The primary endpoint of our study was new-onset atrial fibrillation after pacemaker implantation. The secondary endpoint was the improvement of echocardiographic parameters. Results: We observed in the LBBAP group a mean QRS complex duration of 108.7 ± 8.83 ms (after pacemaker implantation), compared to a much longer duration in the RVP group (143.8 ± 9.851 ms, p = <0.0001). At 1 year of follow-up, 22 (11.82%) patients in the RVP group were diagnosed with new-onset atrial fibrillation, compared to 6 (3.22%) patients out of 186 included in the LBBAP group (p = 0.0017). Regarding LVEF, at follow-up, RVP patients had a decrease in LVEF compared to those in the LBBAP group who had an improved LVEF (54.54 ± 3.77%, p < 0.0001). Conclusions: LBBAP both prevents the onset of atrial fibrillation and improves echocardiographic parameters, especially left ventricular ejection fraction, thus contributing to significantly reducing the risk of developing/worsening advanced heart failure through pacing-induced cardiomyopathy. Full article

Background: Conduction system pacing (CSP), encompassing His bundle pacing (HBP) and left bundle branch area pacing (LBBAP), has emerged as an alternative to conventional pacing methods such as right ventricular pacing (RVP) and biventricular pacing (BVP). This meta-analysis aimed to compare the effects of CSP versus conventional pacing on left ventricular function and selected clinical and electrophysiological outcomes. Methods: Prospective and retrospective studies (randomized, observational, registry-based) reporting pre-post data or direct comparisons between CSP (HBP, LBBAP) and conventional methods (BVP, RVP) for at least one of LVEF, LVESV, LVEDV, QRS duration, NYHA class, NT-proBNP, R-wave, or pacing threshold were included. PubMed and Web of Science databases were searched up to 31 March 2025. Quality assessment (QualSyst), publication bias (Egger’s test, trim-and-fill), subgroup analyses, and meta-regression (follow-up duration) were performed. The review was registered in the INPLASY database (INPLASY202540050). Results: 28 studies (8777 patients, 47 comparisons) were included. CSP significantly improved LVEF (SMD = 1.16; 95%CI: 0.94–1.38), shortened QRS duration (SMD = 0.75; 95%CI: 0.24–1.26), and reduced NYHA class (SMD = 1.94; 95%CI: 1.59–2.29), NT-proBNP levels (SMD = 1.27; 95%CI:0.85–1.69), LVEDV (SMD = 0.90; 95%CI: 0.42–1.38), and LVESV (SMD = 1.31; 95%CI: 0.81–1.81). In head-to-head comparisons, LBBAP and HBP showed similar efficacy, both superior to conventional pacing. Improvement in LVEF significantly correlated with longer follow-up (p = 0.004). Publication bias was non-significant (Egger p = 0.15), despite high heterogeneity (I² > 90%). Conclusions: CSP demonstrated superior clinical and echocardiographic outcomes compared to conventional pacing. Limitations include the predominance of non-randomized studies, high heterogeneity, and variability in follow-up duration, supporting the need for high-quality randomized trials. Full article

Left bundle branch block (LBBB), initially described in the early 20th century, has become increasingly recognized as one of the leading causes of advanced heart failure (HF). In addition to rapidly growing data on guideline-directed medical therapy, cardiac resynchronization therapy (CRT) via transvenous coronary sinus lead has been the gold-standard therapy, but one-third of the indicated patients do not receive the expected benefits. Recently, cardiac conduction system pacing (CSP) was identified as an alternative to traditional CRT strategy, and multiple data have been published during the last few years. This review will discuss the diagnostic criteria of LBBB and its relation to the development of HF and review available data for traditional CRT as well as CSP in depth. Full article

Cardiac resynchronization therapy (CRT) using biventricular (BiV) pacing is the standard treatment for heart failure (HF) patients with reduced left ventricular ejection fraction (LVEF) and electrical dyssynchrony. However, one in three patients remains a non-responder. Left bundle branch area pacing (LBBAP) could represent a more physiological alternative, but its effectiveness is limited in cases of atypical left bundle branch block (LBBB) or intraventricular conduction delay (IVCD). Left Bundle Branch Pacing Optimized cardiac resynchronization therapy (LOT-CRT) integrates LBBAP with coronary sinus (CS) lead pacing to improve electrical synchrony and clinical outcomes. This review evaluates the feasibility, advantages, disadvantages, and clinical outcomes of LOT-CRT. Additionally, we describe our center’s experience and propose an evidence-based implantation algorithm. A review of published studies investigating LOT-CRT was conducted, comparing its effectiveness with BiV-CRT and LBBAP alone using QRS narrowing, LVEF improvement, left ventricular remodeling, New York Heart Association (NYHA) class changes and NT-proBNP levels. It was found that LOT-CRT outperforms BiV-CRT or LBBAP alone in selected populations, at the cost of higher clinical skills, longer procedural times, and specific device setups. Randomized trials are underway to further define its role in clinical practice. Full article

Conduction system pacing started with His bundle pacing (HBP) and then rapidly switched gears into left bundle branch pacing (LBBP). We describe our center’s experience with LBBP using either lumenless leads (LLLs) or stylet-driven leads (SDLs). Patients who were admitted to two tertiary centers between 1 April 2021 and 30 June 2024 and met the guidelines for pacing were recruited and prospectively followed up. A total of 124 patients underwent permanent pacemaker (PPM) implantation using the LBBP technique with a mean follow-up of 19.7 ± 13.3 months. In total, 90 patients were implanted with LLLs and 34 with SDLs. There was no significant difference in the procedural time and final paced QRS duration, but fluoroscopy time was significantly longer in the SDLs (26.2 ± 17.7 min vs. 17.5 ± 13.0 min, respectively, p = 0.026). The on-table impedance values were also significantly higher in the LLLs, and this persisted throughout the follow-up. There were no differences in the rates of complications. The success of conduction system pacing implantation with SDLs and LLLs is comparable with reasonable safety and reliable outcomes. Good pre-implant patient selection will contribute to improved outcomes. Full article

Heart failure with reduced ejection fraction due to ischemic cardiomyopathy remains a significant clinical challenge. Electrical conduction delays exacerbate symptoms by causing uncoordinated contractions, reducing pumping efficiency, and increasing mortality. Right ventricular pacing further worsens dyssynchrony, while resynchronization therapy improves outcomes but has a high non-responder rate. Given these limitations, bundle branch pacing engages the heart’s conduction system, restoring synchronized contraction and enhancing cardiac function. This review examines the impact of left-bundle-branch-block-induced dyssynchrony, the role of advanced imaging in assessing ventricular function, and the clinical outcomes of bundle branch pacing in heart failure patients. Specifically, we explore the mechanical and hemodynamic effects of left bundle branch block, imaging techniques for dyssynchrony evaluation, and the comparative benefits of bundle branch pacing versus resynchronization therapy. Conduction delays impair function, increase myocardial stress, and worsen clinical outcomes. Advanced imaging plays a critical role in patient selection, identifying those most likely to benefit from conduction system pacing. By restoring electrical coordination, bundle branch pacing enhances ventricular function, reduces hospitalizations, and promotes reverse remodeling. It offers similar or superior benefits to conventional resynchronization therapy, regulates stress hormones, reduces oxidative damage, and improves calcium handling. Bundle branch pacing represents a significant advancement in heart failure management, but careful patient selection remains crucial. Future research should focus on optimizing implantation techniques and validating long-term benefits through large-scale clinical trials. Full article

Cardiac resynchronization therapy (CRT) is a cornerstone in the treatment of dyssynchronous heart failure with reduced ejection fraction. However, the phenomenon of non-response has plagued CRT since its initial application. Notwithstanding issues such as failure to capture the left ventricle, lower-than-required pacing delivery percent, and failure to optimize atrioventricular and interventricular delays, there are patients who fail to exhibit an adequate response to CRT in its classical biventricular pacing (BiVP) form. Several modalities have been proposed as a means to remedy this issue, including pacing the conduction system itself—His or left bundle branch pacing, allowing for intrinsic conduction in some myocardial segments, pacing the left ventricle from multiple points in the coronary sinus (multipoint pacing), or even combining the above (e.g., His/left bundle pacing and BiVP leading to His/left bundle-optimized CRT). In the present review, we present recent evidence for the advantages and disadvantages of each modality and attempt to formulate a pathophysiology and simulation-based strategy to determine the best way forward for delivering CRT in non-responders to BiVP. Full article

Most patients with heart failure exhibit ventricular dyssynchrony, which is addressed by cardiac resynchronization therapy, traditionally through the use of biventricular pacing (BVP) devices. Despite this, around 30% of patients do not achieve the desired clinical outcome, and echocardiographic findings show that some patients deteriorate even further. Conduction system pacing (CSP) is a more physiologic pacing technique and includes his-bundle pacing (HBP) and left bundle branch area pacing (LBBAP). In this review, we further discuss and compare various CSP techniques for cardiac resynchronization therapy in patients with heart failure with reduced ejection fraction. After analyzing the current state of the literature on this topic until 2023, eight studies were included in this review and consisted of two trials and five observational studies with a total of 2841 patients. Both BVP and CSP resulted in improved outcomes in terms of NYHA class, QRS duration, and left ventricular ejection fraction over time. These effects were more pronounced in patients undergoing CSP, as the technique is more physiological and results in the synchronized activation of the ventricles. LBBAP yielded better outcomes compared to BVP and resulted in fewer heart failure hospitalizations and a lower all-cause mortality rate. Full article

Cardiac Resynchronization Therapy (CRT) has been established as a major component of heart failure management, resulting in a significant reduction in patient morbidity and death for patients with increased QRS duration, low left ventricular ejection fraction (LVEF), and high risk of arrhythmias. The ability to synchronize both ventricles, lower heart failure hospitalizations, and optimize clinical outcomes are some of the attractive characteristics of biventricular pacing, or CRT. However, the high rate of CRT non-responders has led to the development of new modalities including leadless CRT pacemakers (CRT-P) and devices focused on conduction system pacing (CSP). This comprehensive review aims to present recent findings from CRT clinical trials and systematic reviews that have been published that will likely guide future directions in patient care. Full article

Introduction. Recently published data suggested significantly lower pacing-induced cardiomyopathy (PICM) incidence with conduction system pacing (CSP). Because most data evaluated only the impact on the left ventricle, this study aimed to assess changes in echocardiographic parameters of morphology and function for all heart chambers in patients with baseline preserved and mid-range LVEF over a medium-term follow-up period after CSP. Methods. A total of 128 consecutive patients with LVEF > 40% and successful CSP for bradyarrhythmic indication were prospectively enrolled. A complete 2D echocardiographic examination was performed at baseline and the last follow-up. Results. In total, 38 patients received His bundle pacing (HBP) and 90 received left bundle branch area pacing (LBBAP). The mean follow-up period was 699.2 ± 177.2 days, with 23 patients lost during this period. The ventricular pacing burden for the entire group was 97.2 ± 4.2%. Only three patients (2.9%) met the criteria for PICM. CSP led to a significant increase in LVEF (from 54.2 ± 7.9 to 56.7 ± 7.8%, p = 0.01) and a significant decrease in LV diastolic (from 107.2 ± 41.8 to 91.3 ± 41.8 mL, p < 0.001) and systolic (from 49.7 ± 21.4 to 39.5 ± 18.2 mL, p < 0.001) volumes. There were no significant changes in E/e′, mitral regurgitation, atrial volumes, and right ventricle (RV) diameter. There was a significant improvement in RV function. Tricuspid regurgitation was the only parameter that worsened. There were no differences in evolution for each echocardiographic parameter between the HBP and the LBBAP groups. Conclusions. HBP and LBBAP are equally protective for harmful changes in both atria and ventricles. The prevalence of PICM, defined as a decrease in LVEF, is very low with CSP. Full article

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. Full article