Safety and efficacy of left bundle branch pacing in comparison with conventional right ventricular pacing: A systematic review and meta-analysis

Comparison of ventricular synchrony in children with left bundle branch area pacing and right ventricular septal pacing

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Echocardiographic Evaluation of the Effect on Left Ventricular Function Between Left Bundle Branch Pacing and Right Ventricular Pacing

Purpose

The purpose of this study was to assess the left ventricular function effects of permanent left bundle branch pacing (LBBP) versus traditional right ventricular pacing (RVP).

Patients and Methods

Consecutive patients receiving pacemaker implantation were included and divided into left bundle branch block (LBBB) group and right ventricular pacing (RVP) group. Baseline characteristics were collected, and they received 1-year follow-up. Electrocardiogram (ECG) characteristics and pacing parameters were assessed before and after implantation. Cardiac function parameters such as left ventricular ejection fraction (LVEF) and tricuspid regurgitation (TR) were recorded and compared.

Results

Of 78 patients included, 45 patients received LBBP (mean age, 72.7 ± 12.2 years; male, 55.6%) and 33 patients underwent RVP (mean age 72.9 ± 11.8 years; male, 63.6%). The pacing parameters were satisfactory during the implantation and remained stable during mid-term follow-up. During the follow-up period, LBBP patients had a greater decrease in LVEDD and LVESD. The TR in the LBBP group was significantly improved as compared to the RVP group (P=0.016).

Conclusion

Permanent LBBP achieves favorable cardiac hemodynamic effects with good stability and safety. LBBP may reduce severe TR at 1-year follow-up, and LBBP may be an option for patients with severe TR.

Risk of Atrial Fibrillation Following Left Bundle Branch Area Pacing versus Right Ventricular Pacing and Biventricular Pacing: A Systematic Review and Meta-Analysis

Background

Left bundle branch pacing (LBBP) is a relatively novel physiological pacing strategy with better electrocardiogram characteristics and pacing parameters than other pacing strategies. At present, no meta-analysis or systematic review has examined the risk of atrial fibrillation (AF) after LBBP compared to other pacing strategies.

Methods

We searched the PubMed, Embase, and Cochrane Library databases from inception through September 18, 2022 to identify relevant studies reporting AF incidence rates after LBBP. The incidence of AF following LBBP and that associated with other pacing strategies were extracted and summarized for the meta-analysis. We used odds ratios (ORs) and 95% confidence intervals (CIs) as summary estimates.

Results

Five studies with 1144 participants were included. The pooled rate of AF was 3.7% (95% CI, 0.8%-8.0%) in the LBBP group and 15.5% (95% CI: 9.6%-22.4%) in the other pacing strategies (right ventricular pacing [RVP] and biventricular pacing [BVP]). Compared with other pacing strategies, LBBP was associated with a lower AF risk (OR, 0.33; 95% CI: 0.22-0.51, I 2 = 0.0%; p = 0.485). Similar results were observed for LBBP when compared with RVP (OR: 0.33, 95% CI: 0.22-0.51, I 2 = 0.0%, p = 0.641) and BVP (OR: 0.47, 95% CI: 0.01-15.22, I 2 = 60.4%, p = 0.112).

Conclusions

Compared with BVP and RVP, LBBP was associated with a significantly lower risk of AF. However, further large-sample randomized controlled trials are needed to confirm that LBBP is superior to other pacing strategies in reducing AF risk.

Conduction system pacing in pediatric and congenital heart disease

Conduction system pacing (CSP) has evolved rapidly to become the pacing method of choice for many adults with structurally normal hearts. Studies in this population have repeatedly demonstrated superior hemodynamics and outcomes compared to conventional pacing with the recruitment of the native conduction system. Children and patients with congenital heart disease (CHD) are also likely to benefit from CSP but were excluded from original trials. However, very recent studies have begun to demonstrate the feasibility and efficacy of CSP in these patients, with growing evidence that some outcomes may be superior in comparison to conventional pacing techniques. Concerns regarding the technical challenges and long-term lead parameters of His Bundle Pacing (HBP) have been overcome to many extents with the development of Left Bundle Branch Area Pacing (LBBAP), and both techniques are likely to play an important role in pediatric and CHD pacing in the future. This review aims to assimilate the latest developments in CSP and its application in children and CHD patients.

Clinical Outcomes of Left Bundle Branch Area Pacing in Comparison with Right Ventricular Septal Pacing in Patients with High Ventricular Pacing Ratio ≥40%

Background

Methods

Results

Conclusion

Hemodynamic Effects of Permanent His Bundle Pacing Compared to Right Ventricular Pacing Assessed by Two-Dimensional Speckle-Tracking Echocardiography

We compared the effects of right ventricular (RVP; n = 26) and His bundle (HBP; n = 24) pacing in patients with atrioventricular conduction disorders and preserved LVEF. Postoperatively (1D), and after six months (6M), the patients underwent global longitudinal strain (GLS) and peak systolic dispersion (PSD) evaluation with 2D speckle-tracking echocardiography, assessment of left atrial volume index (LAVI) and QRS duration (QRSd), and sensing/pacing parameter testing. The RVP threshold was lower than the HBP threshold at 1D (0.65 ± 0.13 vs. 1.05 ± 0.20 V, p < 0.001), and then it remained stable, while the HBP threshold increased at 6M (1.05 ± 0.20 vs. 1.31 ± 0.30 V, p < 0.001). The RVP R-wave was higher than the HBP R-wave at 1D (11.52 ± 2.99 vs. 4.82 ± 1.41 mV, p < 0.001). The RVP R-wave also remained stable, while the HBP R-wave decreased at 6M (4.82 ± 1.41 vs. 4.50 ± 1.09 mV, p < 0.02). RVP QRSd was longer than HBP QRSd at 6M (145.0 ± 11.1 vs. 112.3 ± 9.3 ms, p < 0.001). The absolute value of RVP GLS decreased at 6M (16.32 ± 2.57 vs. 14.03 ± 3.78%, p < 0.001), and HBP GLS remained stable. Simultaneously, RVP PSD increased (72.53 ± 24.15 vs. 88.33 ± 30.51 ms, p < 0.001) and HBP PSD decreased (96.28 ± 33.99 vs. 84.95 ± 28.98 ms, p < 0.001) after 6 months. RVP LAVI increased (26.73 ± 5.7 vs. 28.40 ± 6.4 mL/m², p < 0.05), while HBP LAVI decreased at 6M (30.03 ± 7.8 vs. 28.73 ± 8.7 mL/m², p < 0.01). These results confirm that HBP does not disrupt ventricular synchrony and provides advantages over RVP.