Case report of heterotaxy syndrome with sinus node dysfunction and left ventricular hypertrabeculation: clinical and genetic insights

Left bundle branch area (LBBA) pacing (LBBAP) has been proposed as an alternative therapy option in patients indicated for cardiac pacing to treat bradycardia or heart failure. The aim of the study was to evaluate the safety and effectiveness of LBBAP in patients implanted with a Tendril 2088 stylet-driven lead. The international retrospective data collection registry included 11 sites from 5 countries globally. Patients with attempted implants of the Tendril lead in the LBBA were followed for at least 6 months post the implant attempt. The primary safety and efficacy endpoints were freedom from LBBAP lead-related serious adverse events and the composite of LBBA capture threshold of ≤2.0 V and R-wave amplitudes ≥5 mV (or ≥value at implant), respectively. Of 221 patients with attempted implants of the Tendril 2088 lead in the LBBA, 91.4% (202/221) had successful implants for LBBAP. Regardless of the LBBAP implant success, all patients were followed for at least 6 months (8.7 ± 7.3 months). Baseline characteristics: 44% female, 84% ≥65 years old, 34% coronary artery disease, and 86% of primary indications for pacemaker implant. Both primary safety and effectiveness endpoints were met (freedom from LBBAP lead-related serious adverse device effects of 99.5% and electrical performance composite success rate of 93%). The capture thresholds in LBBAP at implant and 6 months were 0.8 ± 0.3 V@0.4 ± 0.1 ms and 0.8 ± 0.3 V@0.4 ± 0.1 ms. The rate of patients with capture threshold rise ≥1 V was 1.5% through 6 months. The R-wave amplitudes in LBBAP at implant and 6 months were 9.3 ± 3.2 mV and 10.6 ± 3.0 mV. This large multicenter study demonstrates that the stylet-driven Tendril™STS 2088 lead is safe and effective for LBBAP with high success and low complication rates.

Effectiveness of left bundle branch area pacing to restore narrow QRS in patients with right bundle branch block

Atrioventricular block (AVB) is a frequent complication in patients undergoing transcatheter aortic valve implantation (TAVI). Right apex ventricular pacing (RVP) represents the standard treatment but may induce cardiomyopathy over the long term. Left bundle branch area pacing (LBBAP) is a promising alternative, minimizing the risk of desynchrony. However, available evidence with LBBAP after TAVI is still low. To assess the feasibility and safety of LBBAP for AVB post-TAVI compared with RVP. Consecutive patients developing AVB early after TAVI were enrolled between 1 January 2022 and 31 December 2022 at three high-volume hospitals and received LBBAP or RVP. Data on procedure and at short-term follow-up (at least 3 months) were collected. A total of 38 patients (61% men, mean age 83 ± 6 years) were included; 20 patients (53%) received LBBAP. Procedural success was obtained in all patients according to chosen pacing strategy. Electrical pacing performance at implant and after a mean follow-up of 4.2 ± 2.8 months was clinically equivalent for both pacing modalities. In the LBBAP group, procedural time was longer (70 ± 17 versus 58 ± 15 min in the RVP group, P = 0.02) and paced QRS was shorter (120 ± 19 versus 155 ± 12 ms at implant, P < 0.001; 119 ± 18 versus 157 ± 9 ms at follow-up, P < 0.001). Complication rates did not differ between the two groups. In patients with AVB after TAVI, LBBAP is feasible and safe, resulting in a narrow QRS duration, either acutely and during the follow-up, compared with RVP. Further studies are needed to evaluate if LBBAP reduces pacing-induced cardiomyopathy in this clinical setting.

Comparing Left Bundle Branch Area vs Right-Ventricular Septal Pacing in High-Degree Conduction Disease After Transcatheter Aortic Valve Replacement: Randomized Trial Study Protocol

Left bundle branch–optimized cardiac resynchronization therapy: Pursuing the optimal resynchronization in severe (distal) conduction system disease

Navik 3D (APN Health, Waukesha, WI, USA) is a navigation software program that uses two-dimensional (2D) fluoroscopy images to provide three-dimensional (3D) information. Left bundle branch area (LBBA) pacing (LBBAP) is a novel physiologic pacing technique where the lead is placed in the right ventricular (RV) basal septum to capture the left bundle branch (LBB). Precise lead placement in this region can be challenging using 2D fluoroscopy. We studied the feasibility of using Navik 3D to identify the location, plane, and depth of the lead in the septum to assist with LBBAP procedures. This observational, prospective single-center study included 14 patients undergoing LBBAP. Navik 3D was used to identify the LBBA, RV septum, RV apex, and lead position in three dimensions using two orthogonal 2D views. The 3D images were overlaid on real-time, gated fluoroscopic images for navigation of the lead. Images of the 3D locations and successful or unsuccessful lead locations were projected onto 2D fluoroscopic images, allowing for repositioning if necessary. All attempted patients had successful LBBA lead implants. An LBB potential was recorded in 61.5% of the patients. Selective LBBAP was achieved in 85% of the patients. The mean QRS duration postimplant was 129.8 ± 13.1 ms. The mean left ventricular activation time (stimulus R-wave peak in V6) postimplant was 75 ± 12 ms. No acute complications were recorded. 3D localization of the LBBA using the Navik 3D mapping system was feasible and may assist with more appropriate LBBA lead placement.

Comparison of immediate changes of repolarization parameters after left bundle branch area pacing and traditional biventricular pacing in heart failure patients

Background/Introduction Conduction system pacing (CSP), encompassing His bundle pacing (HBP) and left bundle branch area pacing (LBBAP), has gained prominence in treating bradycardia and heart failure in recent years. Despite its increasing utilization, data on real-world adoption of CSP are limited. Purpose The C-SING study aimed at assessing patient characteristics, implant success, procedural details, and safety of CSP when performed in routine clinical practice. Methods Periprocedural data from 27 experienced CSP centers across Italy were collected on patients undergoing CSP implantation for various indications between January 2021 and January 2024. Results The study comprised 1,317 patients (median age 78 years [interquartile range, 71-83], male 66.2%). Leading indications included atrioventricular (AV) block (40.8%), sinus node dysfunction (12.1%), atrial fibrillation with bradycardia (9.7%), AV node ablation (9.5%), and heart failure (12.5%). Pacemakers were implanted in 77.3% of patients, cardiac resynchronization devices in 21.7%, and implantable cardioverter-defibrillators in 1.0%. Stylet-driven and lumenless CSP leads were utilized in 64.7% and 35.3% of procedures, respectively. Final 12-lead ECG assessment revealed LBBAP capture in 88.7% patients, HBP in 8.4% (selective 4.2%, non-selective 4.2%), and no CSP capture in 3.0%, resulting in a 97.0% CSP lead implantation success rate. In patients with LBBAP, predominant capture types were left bundle branch pacing (19.6%), left posterior fascicular pacing (19.2%), and left septal fascicular pacing (14.8%). Comparing HBP to LBBAP, the latter showed shorter procedural time (60 minutes [45-80] vs. 70 minutes [60-95], p=0.003), but similar fluoroscopy time (6.0 minutes [3.3-10.8] vs. 6.1 minutes [4-10], p=0.735). Paced QRS duration was longer in LBBAP (118 ms [105-130]) compared to HBP (110 ms [101-122], p&amp;lt;0.001). LBBAP showed lower capture thresholds (0.6 V [0.5-0.9] @0.4 ms vs. 0.8 V [0.5-1.5] @1.0 ms, p&amp;lt;0.001) and higher R-wave sensing (10.7 mV [8-16] vs. 4.5 mV [2.4-9.9], p&amp;lt;0.001). The rate of periprocedural complications was higher in patients with LBBAP than HBP (7.3% vs. 1.8%, p=0.03), with the most frequent events being intraprocedural perforation into the left ventricular cavity during lead screwing (2.6%) and CSP lead dislodgment before hospital discharge (1.4%). These occurrences necessitated lead repositioning without additional complications. Conclusion CSP demonstrated feasibility as a primary pacing strategy for various indications in a real-world, multicenter setting. LBBAP, more frequently used than HBP, exhibited shorter procedural time and superior acute electrical parameters. LBBAP revealed a higher rate of minor procedural complications than HBP. Further investigations, supported by additional long-term outcome data, are essential to comprehensively assess CSP performance.

BackgroundConduction system pacing (CSP), including His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP), has been used as an alternative for pacemaker indicated patients requiring ventricular pacing. ObjectiveThe purpose of this study was to characterize the safety and performance of HBP and LBBAP among patients enrolled in the Medtronic product surveillance registry (PSR). MethodsThis observational analysis included patients who underwent pacemaker implantations for HBP or LBBAP with a Medtronic Model 3830 lead between January 2019 and December 2023 in the Medtronic PSR. The primary outcomes were lead-related complications and pacing capture threshold. Baseline characteristics, R-wave amplitude, impedance, and all-cause mortality were summarized. ResultsA total of 2342 patients were included across 77 centers (mean age 74 years; 38.9% female). Of the patients implanted with a 3830 lead for CSP, 64.1% (n = 1502) had LBBAP placement and 35.9% (n = 840) had HBP placement. The most commonly reported indications for CSP were sinus node dysfunction (67.0%) and atrioventricular block (57.2%). LBBAP had lower pacing thresholds, higher R-wave sensing, and higher impedance (all P <.001) through 30 months. At 36 months postimplant, the lead complication rate for LBBAP and HBP was 2.5% and 6.3%, ,respectively with no difference in all-cause mortality. ConclusionIn a multicenter cohort of LBBAP and HBP patients treated with the catheter-delivered 3830 lead, lead-related complication rates were low and electrical parameters were stable through 30 months.

Background: Left bundle branch area pacing (LBBAP) has shown promising outcomes at experienced centers, but less is known about the learning curve with new adoption of LBBAP. We conducted a retrospective analysis (2020-2023) of the learning curve for LBBAP at our center. Methods: Procedural success and complications in adult patients undergoing LBBAP by operators with &gt;5-years’ experience in device implantation were compared between operators’ experience ≤10th (LBBAPinexp) vs. &gt;10th (LBBAPexp) LBBAP implant. Successful LBBAP was defined as left ventricular activation time (LVAT) ≤80 ms. Results: Seven operators implanted LBBAP in 288 patients (age 73±11 years, 38% women): 68 (24%) in LBBAPinexp vs. 220 (76%) patients in LBBAPexp groups with similar baseline characteristics (all p &gt;0.05). The median number of implants per operator was 22 (range 8-83). Table 1 shows the procedural characteristics and ECG results. Post-implant LVAT ≤80 ms was less frequent in LBBAPinexp compared to LBBAPexp (56.9% vs 72.4%, p=0.04, Figure 1). There were no differences in paced QRS duration ≤130 ms (75.9% vs. 76.1 %, p=1.0) or operator self-identified success (85% vs. 91%, p=0.2). With new single-/dual-chamber device implants, there was no difference in implant duration (103.4±31.8 vs. 101.6±38.5 minutes, p=0.3) but there was longer fluoroscopy in LBBAPinexp (12.6±10.1 vs. 8.2±8.0 minutes, p&lt;0.0001, Figure 1). The average number of attempts at LBBAP was lower in LBBAPinexp vs. LBBAPexp (2.0 ± 1.5 vs. 2.9 ± 2.9, p=0.03). There was no difference in complications between the 2 groups (Table 2). Conclusion: Operators use less fluoroscopy, make more attempts at LBBAP and more frequently achieve LVAT ≤80 ms after their first 10 implants.

Left bundle branch area pacing (LBBAP) may be an alternative to biventricular pacing (BVP) for cardiac resynchronization therapy (CRT). We sought to compare the acute hemodynamic and ECG effects of LBBAP, BVP, and left bundle-optimized therapy CRT (LOT-CRT) in CRT candidates with advanced conduction disease. In this multicenter study, 48 patients with either nonspecific interventricular conduction delay (n=29) or left bundle branch block (n=19) underwent acute hemodynamic testing to determine the change in left ventricular pressure maximal first derivative (LV dP/dtmax) from baseline atrial pacing to BVP, LBBAP, or LOT-CRT. Atrioventricular-optimized increases in LV dP/dtmax for LOT-CRT (mean, 25.8% [95% CI, 20.9%-30.7%]) and BVP (26.4% [95% CI, 20.2%-32.6%]) were greater than unipolar LBBAP (19.3% [95% CI, 15.0%-23.7%]) or bipolar LBBAP (16.4% [95% CI, 12.7%-20.0%]; P≤0.005). QRS shortening was greater in LOT-CRT (29.5 [95% CI, 23.4-35.6] ms) than unipolar LBBAP (11.9 [95% CI, 6.1-17.7] ms), bipolar LBBAP (11.7 ms [95% CI, 6.4-17.0]), or BVP (18.5 [95% CI, 11.0-25.9] ms), all P≤0.005. Compared with patients with left bundle branch block, patients with interventricular conduction delay experienced less QRS reduction (P=0.026) but similar improvements in LV dP/dtmax (P=0.29). Bipolar LBBAP caused anodal capture in 54% of patients and resulted in less LV dP/dtmax improvement than unipolar LBBAP (18.6% versus 23.7%; P<0.001). Subclassification of LBBAP capture (European Heart Rhythm Association criteria) indicated LBBAP or LV septal pacing in 27 patients (56%) and deep septal pacing in 21 patients (44%). The hemodynamic benefit of adding left ventricular coronary vein pacing to LBBAP depended on baseline QRS duration (P=0.031) and success of LBBAP (P<0.004): LOT-CRT provided 14.5% (5.0%-24.1%) greater LV dP/dtmax improvement and 20.8 (12.8-28.8) ms greater QRS shortening than LBBAP in subjects with QRS ≥171 ms and deep septal pacing capture type. In a CRT cohort with advanced conduction disease, LOT-CRT and BVP provided greater acute hemodynamic benefit than LBBAP. Subjects with wider QRS or deep septal pacing are more likely to benefit from the addition of a left ventricular coronary vein lead to implement LOT-CRT. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04905290.

Left bundle branch area pacing: How to prevent a coronary venous fistula.

Performance of an active fixation stylet-driven lead in left bundle branch area pacing: Results from INSIGHT-LBBA.

Initial Experience, Safety, and Feasibility of Left Bundle Branch Area Pacing

Left bundle branch area pacing (LBBAP) has recently been reported to be a new, clinically feasible and safe physiological pacing strategy. The present study aims to investigate the usefulness of LBBAP in reducing mechanical dyssynchrony compared with right ventricular septal pacing (RVSP). A total of 39 LBBAP patients, 42 RVSP patients, and 93 healthy control participants were retrospectively evaluated. We compared phase analysis- (bandwidth, phase standard deviation [PSD], entropy) and regional wall motion analysis parameters. Wall motion analysis parameters included the time to the end-systolic frame (TES) assessed using single-photon emission computed tomography analysis. The maximum differences between segmental TES (MDTES), the standard deviation of TES (SDTES), and the TES difference between the lateral and septal segments (DTES-LS) were obtained. All phase analysis parameters were significantly smaller in the LBBAP group than in the RVSP group (bandwidth: LBBAP, 74 ± 31° vs. RVSP, 102 ± 59°, p = .009; PSD: LBBAP, 19 ± 6.7° vs. RVSP, 26 ± 15°, p = .007; entropy: LBBAP, 0.57 ± 0.07 vs. RVSP, 0.62 ± 0.11 p = .009). The regional wall motion analysis parameters were also smaller in the LBBAP group than in the RVSP group (MDTES:LBBAP, 17 ± 7.1% vs. RVSP, 25 ± 14%, p = .004; SDTES:LBBAP, 4.5 ± 1.7% vs. RVSP, 6.0 ± 3.5%, p = .015; DTES-LS: LBBAP, 4.1 ± 3.4% vs. RVSP, 7.1 ± 5.4%, p = .004). All phase analysis and wall motion analysis parameters were same in the LBBAP and control groups. LBBAP may reduce mechanical dyssynchrony and achieve greater physiological ventricular activation than RVSP.