Left bundle branch area pacing (LBBAP) has developed in an effort to improve cardiac resynchronization therapy (CRT). We aimed to compare the long-term clinical outcomes between LBBAP and biventricular pacing (BIVP) in patients with heart failure (HF) and complete left bundle branch block (CLBBB). Consecutive patients with HF and CLBBB requiring CRT received either LBBAP or BIVP were recruited at the Second Affiliated Hospital of Nanchang University from February 2018 to May 2019. We assessed their implant parameters, electrocardiogram (ECG), clinical outcomes at implant and during follow-up at 1, 3, 6, 12, and 24 months. Forty-one patients recruited including 21 for LBBAP and 20 for BIVP. Mean follow-up duration was 23.71 ± 4.44 months. LBBAP produced lower pacing thresholds, shorter procedure time and fluoroscopy duration compared to BIVP. The QRS duration was significantly narrower after LBBAP than BIVP (129.29 ± 31.46 vs. 156.85 ± 26.37 ms, p = 0.005). Notably, both LBBAP and BIVP significantly improved LVEF, LVEDD, NYHA class, and BNP compared with baseline. However, LBBAP significantly lowered BNP compared with BIVP (416.69 ± 411.39 vs. 96.07 ± 788.71 pg/ml, p = 0.007) from baseline to 24-month follow-up. Moreover, patients who received LBBAP exhibited lower number of hospitalizations than those in the BIVP group (p = 0.019). In addition, we found that patients with moderately prolonged left ventricular activation time (LVAT) and QRS notching in limb leads in baseline ECG respond better to LBBAP for CLBBB correction. LBBAP might be a relative safe and effective resynchronization therapy and as a supplement to BIVP for patients with HF and CLBBB.

Background:The comparative effects of different types of cardiac resynchronization therapy (CRT) delivered by biventricular pacing (BVP), His bundle pacing (HBP), and left bundle branch area pacing (LBBAP) remain inconclusive.Hypothesis: HBP and LBBAP may be advantageous over BVP for CRT.Methods: PubMed, Embase, Web of Science, and the Cochrane Library were systematically searched for studies that reported the effects after BVP, HBP, and LBBAP for CRT. The effects between groups were compared by a frequentist random-effects network meta-analysis (NMA), by which the mean differences (MDs) and 95% confidence intervals (CIs) were calculated.Results: Six articles involving 389 patients remained for the final meta-analysis. The mean follow-up of these studies was 8.03 ± 3.15 months. LBBAP resulted in a greater improvement in LVEF% (MD = 7.17, 95% CI = 4.31 to 10.04), followed by HBP (MD = 4.06, 95% CI = 1.09 to 7.03) compared with BVP. HBP resulted in a narrower QRS duration (MD = 31.58 ms, 95% CI = 12.75 to 50.40), followed by LBBAP (MD = 27.40 ms, 95% CI = 10.81 to 43.99) compared with BVP. No significant differences of changes in LVEF improvement and QRS narrowing were observed between LBBAP and HBP. The pacing threshold of LBBAP was significantly lower than those of BVP and HBP. Conclusion:The NMA first found that LBBAP and HBP resulted in a greater LVEF improvement and a narrower QRS duration compared with BVP. Additionally, LBBAP resulted in similar clinical outcomes but with lower pacing thresholds, and may therefore offer advantages than does HBP for CRT.

Cardiac resynchronization therapy (CRT) via biventricular pacing (BVP) improves morbidity, mortality, and quality of life, especially in subsets of patients with impaired cardiac function and wide QRS. However, the rate of unsuccessful or complicated left ventricular (LV) lead placement through coronary sinus is 5–7%, and the rate of “CRT non-response” is approximately 30%. These reasons have pushed physicians and engineers to collaborate to overcome the challenges of LV lead implantation. Thus, various alternatives to BVP have been proposed to improve CRT effectiveness. His bundle pacing (HBP) has been increasingly used by activating the His–Purkinje system but is constrained by challenging implantation, low success rates, high and often unstable thresholds, and low perception. Therefore, the concept of pacing a specialized conduction system distal to the His bundle to bypass the block region was proposed. Multiple clinical studies have demonstrated that left bundle branch area pacing (LBBAP) has comparable electrical resynchronization with HBP but is superior in terms of simpler operation, higher success rates, lower and stable capture thresholds, and higher perception. Despite their well-demonstrated effectiveness, the transvenous lead-related complications remain major limitations. Recently, leadless LV pacing has been developed and demonstrated effective for these challenging patient cohorts. This article focuses on the current state and latest progress in HBP, LBBAP, and leadless LV pacing as alternatives for failed or non-responsive conventional CRT as well as their limits and prospects.

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Objective: This study aimed to investigate the relationship between the location of implantation of the Left Bundle Branch Area Pacing (LBBAP) electrode and the coronary artery and to assess the safety of LBBAP surgery. Methods: Patients who underwent the LBBAP procedure and coronary angiography (CAG) at the Second Affiliated Hospital of Nanchang University between January 1, 2019 to October 1, 2020 were included. We read the patient’s LBBAP and CAG imaging data and used the nine-partition method to measure the vertical distance from the tip of the pacing electrode to each coronary artery in multiple projection positions during the ventricular systolic period. Changes in the ST-T segment in the electrocardiogram, serum troponin and myocardial enzyme profiles were observed before and after the LBBAP surgery. Results: Overall, 50 patients were evaluated. The average vertical distances from the electrode tip to the left anterior descending branch (LAD), right posterior coronal descending branch (PD), left posterior ventricular branch (PL) were 19.69±8.72 mm, 26.09±8.02 mm, and 21.11±7.86 mm, respectively. The minimum were 5.28 mm, 9.51 mm and 8.69 mm, respectively. CAG in all patients showed no significant injury to the ventricular septal branch. And there were no elevated serum troponin or cardiac enzyme profiles. Conclusions: This study suggested that the coronary arteries were safest when the LBBAP electrodes were placed within a rectangle formed by the PM, M, PI, and MI center points. The PM was the ideal position to implant the LBBAP electrodes, which had a low risk of coronary vascular injury.

The feasibility and safety of left bundle branch area pacing (LBBAP) used in pediatric patients with atrioventricular block (AVB) have not been well demonstrated. Currently, only several case reports for pediatric patients have been published since the advent of LBBAP, with 3 months to 1 year follow-up. Here, we present a case of LBBAP in a 6-year-old child with a high-degree AVB secondary to the transcatheter device closure of congenital ventricular septal defect. No procedure-related complications were observed, and the electrical parameters were stable at 2-year follow-up. Additionally, we performed a systematic literature review on pediatric patients with LBBAP. Fifteen cases were retrieved after systematically searching PubMed and Embase databases. No complications have been reported among these published cases. In conclusion, consistent with previous cases, our case with 2-year follow-up has demonstrated that LBBAP may be an alternative pacing modality from a very early age. However, given the limited evidence, the long-term outcomes of LBBAP in pediatric patients should be further investigated.