His Bundle Pacing in Heart Failure-Concept and Current Data

Early outcomes of left bundle branch area pacing in children

OBJECTIVE

Left bundle branch area pacing is a recent technique gaining rapid acceptance due to its broader target area and excellent electrical parameters. The aim of this study was to demonstrate the feasibility of left bundle branch area pacing in children and share short-term results.

MATERIALS AND METHODS

A retrospective study conducted at a single centre between December 2021 and April 2024 involved 19 children who underwent left bundle branch area pacing using Select Secure leads. The study included echocardiographic evaluations, pacing parameters, and follow-up outcomes.

RESULTS

The cohort comprised 10 males and 9 females. Median age was seven years (range 2-18), and median weight was 38 kg (range 13-56). All patients had complete atrioventricular block, with seven having isolated congenital complete atrioventricular block and 12 postoperative complete atrioventricular block. In nine patients, transitioning from epicardial to endocardial pacing resulted in ventricular dysfunction due to chronic right ventricular pacing. The remaining patients received left bundle branch area pacing initially. One patient underwent implantation in a septal position close to the left bundle due to left bundle branch area pacing infeasibility. The median post-procedure QRS duration was 92 msec (range 80-117). Median R wave amplitude, threshold, and impedance values were 14.7 mV (range 13.3-16.8), 0.7 mV (range 0.5-1.1), and 728 ohms (range 640-762), respectively. Atrioventricular (DDD mode) leads were implanted in 10 patients, and ventricular leads (VVIR mode) were implanted in nine patients. Median fluoroscopy dose was 18.7 mGy (13.5-34.52).

CONCLUSION

Left bundle branch area pacing can be safely conducted in paediatric patients exhibiting a narrow QRS duration and stable pacing parameters.

Clinical outcomes of His bundle pacing vs. right ventricular pacing in patients with conduction disturbances following transcatheter aortic valve replacement

OBJECTIVE

To assess and compare the clinical outcomes of His bundle pacing (HBP) versus right ventricular pacing (RVP) in patients who develop conduction disturbances following transcatheter aortic valve replacement (TAVR).

METHODS

In this retrospective study, 120 patients who developed CD following TAVR were enrolled, and were implanted with HBP or RVP between January 2015 and December 2024. To adjust for variations in initial risk factors and baseline characteristics between patients who underwent HBP or RVP, we employed the propensity score matching. Each patient was matched in a 1:1 ratio with replacement. Patients who either received HBP or RVP, but could not be adequately matched, were excluded from the study population. Procedural and clinical outcomes were compared among different modalities at pacing implantation and12-month follow-up.

RESULTS

Paced QRS duration, R-wave amplitude at implantation and at follow-up, impedance at follow-up were lower in HBP group compared to RVP group. At12-month follow-up, the decrease in pacing burden was significantly greater in the HBP group than in the RVP group. Pacing threshold at implantation and at follow-up and capture threshold at implantation and at follow-up were higher in HBP group compared to RVP group. During follow-up, the left ventricular ejection fraction (LVEF) and tricuspid regurgitation (TR) area in the HBP group showed a significant improvement compared to preoperative values, while no significant increase in LVEF was observed in the RVP group, with a clear statistical difference between the two groups. At 12-month follow-up, NT-proBNP levels in the HBP group were significantly lower than those in the RVP group. The rates of NYHA functional class II were higher, while the rates of NYHA functional class III and MACE were lower in the HBP group compared to the RVP group during follow-up.

CONCLUSIONS

HBP was feasible and safe in patients after TAVR, demonstrating a reduction in the composite outcome of MACE and better cardiac function compared to RVP.

Cardiac resynchronization therapy in heart failure patients: tough road but clear future

Cardiac resynchronization therapy (CRT) based on biventricular pacing (BVP) is an invaluable intervention currently used in heart failure (HF) patients. The therapy involves electromechanical dyssynchrony, which can not only improve heart function and quality of life but also reduce hospitalization and mortality rates. However, approximately 30% to 40% of patients remain unresponsive to conventional BVP in clinical practice. In the recent years, extensive research has been employed to find a more physiological approach to cardiac resynchronization. The His-Purkinje system pacing (HPSP) including His bundle pacing (HBP) and left bundle branch area pacing (LBBaP) may potentially be the future of CRT. These technologies present various advantages including offering an almost real physiological pacing, less complicated procedures, and economic feasibility. Additionally, other methods, such as isolated left-ventricular pacing and multipoint pacing, may in the future be important but non-mainstream alternatives to CRT because currently, there is no strong evidence to support their effectiveness. This article reviews the current situation and latest progress in CRT, explores the existing technology, and highlights future prospects in the development of CRT.

The efficacy of left bundle branch area pacing compared with biventricular pacing in patients with heart failure: A matched case-control study

BACKGROUND

Left bundle branch area pacing (LBBAP) was reported to improve cardiac function by correcting complete left bundle branch block (CLBBB). Our study aimed to compare the efficacy of LBBAP and biventricular pacing (BIVP) in heart failure patients with CLBBB.

METHODS

Ten patients prospectively underwent LBBAP (LBB-CRT group) and 30 patients received BIVP (BIV-CRT group) were matched using propensity score matching. LBBAP was achieved by the trans-interventricular septum method. Echocardiography, electrocardiogram, NYHA classification, and blood B-type natriuretic peptide concentration were evaluated at preimplantation and at 6-month follow up. CRT response was defined as at least 15% decrease in left ventricular end-systolic volume.

RESULTS

In the LBB-CRT group, CLBBB were successfully corrected by LBBAP with no complications. QRS duration (QRSd) significantly decreased after implantation in both groups, and the decrease of QRSd in the LBB-CRT group was significantly greater than that in the BIV-CRT group (60.80 ± 20.09 vs. 33.00 ± 21.48 ms, p = .0009). The echocardiographic measurements including left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular ejection fraction significantly improved after 6 months in both groups. The response rate was significantly higher in LBB-CRT group than BIV-CRT group (100.00% vs. 63.33%, p = .038). The percentage of patients in New York Heart Association classification Grades I and II was significantly higher in the LBB-CRT group compared with that in the BIV-CRT group (median 1.5 vs. 2.0, p = .029) at 6-month follow-up.

CONCLUSIONS

It is effective and safe to correct CLBBB with LBBAP in heart failure patients. Compared with BIVP, LBBAP can better optimize electrical synchrony and improve cardiac function.

The Past, Present and Future of Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) has revolutionized the care of the patients with heart failure with reduced ejection fraction and electrical dyssynchrony. The current guidelines for patient selection include measurement of left ventricular systolic function, QRS duration and morphology, and functional classification. Despite consistent and increasing evidence supporting CRT use in appropriate patients, CRT has been underutilized. Notwithstanding the heterogeneous definitions of non-response, more than one-third of patients demonstrate a lack of echocardiographic reverse remodeling or poor clinical outcome following CRT. Since the causes of this non-response are multifactorial, it will require multidisciplinary efforts to overcome including optimal patient selection, procedural strategies, as well as optimizing post-implant care in patients undergoing CRT. The innovations of novel pacing approaches combined with advanced imaging technologies may eventually offer a personalized CRT system uniquely tailored to each patient's dyssynchrony signature.