Initial Experience of Left Bundle Branch Area Pacing Using Stylet-Driven Pacing Leads: A Multicenter Study

Authors, Journal, Affiliations, Type, DOI

• Authors: Jan De Pooter, MD, PhD; Emine Ozpak, MD; Simon Calle, MD; Peter Peytchev, MD; Ward Heggermont, MD, PhD; Sebastien Marchandise, MD; Frank Provenier, MD, PhD; Bart Francois, MD; Wim Anné, MD, PhD; Peter Pollet, MD, PhD; Cynthia Barbraud, MD; Kris Gillis, MD, PhD; Frank Timmermans, MD, PhD; Frederic Van Heuverswyn, MD; Roderick Tung, MD; Aurélien Wauters, MD, PhD; Jean-Benoit le Polain de Waroux, MD, PhD. (17 authors)
• Journal: J Cardiovasc Electrophysiol 2022;33:1540–1549. © 2022 Wiley Periodicals LLC. Received 21 February 2022; revised 10 May 2022; accepted 19 May 2022
• Affiliations: Eight Belgian centres — Heart Center, University Hospital Ghent; Hartcentrum OLV Aalst; Institut Cardiovasculaire, Cliniques Universitaire Saint-Luc, UCL Louvain, Bruxelles; Dienst Cardiologie, AZ Maria Middelares, Ghent; Dienst Cardiologie AZ Delta, Roeselare; Service Cardiologie, Citadelle Château Rouge, Liège; Dienst Cardiologie AZ Sint Jan, Brugge; plus the Division of Cardiology, University of Arizona College of Medicine-Phoenix, and Service de Cardiologie, Clinique Saint Pierre, Ottignies
• Type: Prospective, multicentre, consecutive-enrolment observational registry. No control group, no randomisation, no comparator arm. Implant success 94.6% (334/353)
• DOI: 10.1111/jce.15558
• Disclosures: De Pooter (Medtronic, Biotronik speaker fees/honoraria); Peytchev and Heggermont — their institution (CRI Aalst) receives consultancy fees from Medtronic, Biotronik, St Jude Medical, Boston Scientific and Microport on their behalf; Wauters (Biotronik); le Polain de Waroux (Medtronic, Boston Scientific, Abbott, Biotronik — proctoring and teaching); Tung (Medtronic, Boston Scientific, Abbott, Biotronik). The lead and sheath studied are Biotronik products, and Biotronik is a disclosed funder of several authors — a relationship to weigh when reading the favourable safety and ease-of-use conclusions

Overview

This registry asks whether left bundle branch area pacing (LBBAP) can be performed with ordinary stylet-driven pacing leads (SDL) rather than the specialised lumenless lead (Medtronic SelectSecure 3830) that nearly all published LBBAP experience had used. Between eight Belgian hospitals, 353 consecutive patients were implanted with the Solia S60 (Biotronik, 5.6 Fr, extendable helix) through a dedicated Selectra3D sheath, with implant success defined as either left bundle branch pacing or left ventricular septal pacing. Success was 94.6%, unipolar thresholds were low (0.6 ± 0.4 V at 0.4 ms) and stable to 12 months, and — the study's most consequential finding — success was independent of centre volume (93–100% across centres, p = .75), including centres with as few as 5 implants. The safety signal cuts the other way from the lumenless literature: septal perforation (2%) and septal coronary artery fistula (1.4%) occurred at rates above those reported for lumenless leads, though all perforations were asymptomatic and no ventricular septal defect or septal haematoma persisted. Its central limitation is definitional — only 73% of "successful" implants achieved actual left bundle capture, so the remaining 27% were pure myocardial (LVSP) pacing, a looser criterion than the reports it is implicitly measured against.

Keywords

left bundle branch area pacing; left ventricular septal pacing; physiologic pacing; stylet-driven pacing leads

Key Takeaways

1 | Introduction

• Right ventricular pacing (RVP) has been the standard ventricular pacing modality for decades, but induces a dyssynchronous contraction pattern that may cause pacing-induced cardiomyopathy, adverse haemodynamic effects and even increased mortality
• Conduction system pacing emerged as an alternative for physiological pacing. His bundle pacing (HBP), deemed most physiological, is limited by high capture thresholds, low sensing amplitudes and low implant success in patients with infranodal conduction disease
• LBBAP is an attractive alternative: comparable haemodynamic effects to HBP but with lower and more stable pacing thresholds, higher sensing amplitudes and higher implant success
• The evidence gap this study fills: the vast majority of published LBBAP reports used a specialised lumenless pacing lead (LLL) delivered through a preshaped sheath. LBBAP using standard SDL had been proposed by the same group as feasible, but only in small series

2 | Methods

2.1 | Study population

• Prospective enrolment of consecutive adults undergoing LBBAP for anti-bradycardia pacing or heart failure indications at eight Belgian hospitals
• LBBAP was attempted as first-choice pacing strategy, or after a failed HBP or failed conventional CRT attempt
• Approved by local ethics committees of participating centres and the central ethics committee of Ghent University Hospital; written informed consent obtained

2.2 | LBBAP via stylet-driven pacing leads — the technique

The preparation steps are the practical core of the paper, because an extendable helix must be prevented from retracting while the outer lead body is rotated:

• Lead and sheath: 5.6 Fr stylet-driven lead with extendable helix (Solia S60; Biotronik) delivered through a preshaped sheath (Selectra3D; Biotronik)
• Step 1 — extend the helix using the white fixation tool
• Step 2 — pretension the lead: push the green stylet insertion tool onto the lead pin and rotate clockwise 10–15 times to build up torque on the inner coil
• Step 3 — maintain the stored torque: without losing the build-up tension, push the stylet insertion tool further over the first adjacent silicone seal. These steps ensure torque applied to the outer lead body is transferred to the inner coil and helix, decreasing the risk of helix retraction
• Delivery: sheath advanced to the right ventricle over the wire; lead introduced; sheath positioned perpendicular to the interventricular septum by counter-clockwise rotation
• Target site: 1 cm inferior and distal to the His bundle region in the RAO view. Correct septal position confirmed by delineating the right-sided septum with contrast injection in LAO view
• At the correct septal position a "W"-shaped QRS morphology in V1 is generally recorded on unipolar pacing from the extended helix
• Screwing in: clockwise rotation of the outer lead body; lead advancement assessed in LAO 25–35°. While screwing, the stylet was kept advanced to the tip of the lead and the stylet insertion tool remained connected to the pin to maintain inner-coil torque
• ECG progression as the guide: as the lead advanced, the "W" pattern in V1 gradually narrowed and evolved to a Qr, qR, or rSR pattern — the so-called incomplete RBBB pattern
• Guidance was multimodal: contrast injections, unipolar paced QRS morphology, and monitoring of unipolar pacing impedance
• Pacing during deployment was either intermittent at different steps or continuous while screwing (operator preference). Unipolar pacing impedances were measured either on the lead pin or on the stylet to allow continuous pacing while screwing
• Hygiene of the helix: upon each new screw attempt the lead was removed from the sheath and inspected for remaining tissue at the helix, which was cleaned before a new attempt

2.3 | Defining successful LBBAP

• Successful LBBAP = LBBP (left-sided conduction system capture) OR LVSP (pure myocardial capture). This composite definition is the study's most important methodological choice and is addressed in Limitations
• Four criteria were used to define the pacing response:
  1. Appearance of a Qr, qR, or rSr pattern in lead V1
  2. Observed transition in pacing response (nonselective, selective LBBP, or myocardial capture) with changes in unipolar pacing output
  3. Stimulus to peak LV activation time (LVAT — interval from stimulus to R-wave peak time in V6**)** remaining shortest and constant at both low and high output, or shortening abruptly by >10 ms with increasing output
  4. Stimulus to LVAT <80 ms in baseline narrow QRS or RBBB, or <100 ms in LBBB or IVCD
• Patients meeting criterion 1 plus at least one other were deemed LBBP
• If a narrow Qr or qR pattern in V1 was seen without other criteria, despite a deep septal position → LVSP
• In patients without r′ in V1 despite confirmed deep septal position, with narrow paced QRS and significant QRS narrowing (vs right-sided septal pacing) → also labelled LVSP
• Acceptance of the final lead position was left to the discretion of the implanting physician
• On failure: the Solia S60 was left in the RV apex (bradycardia indication) or switched to biventricular pacing with the Solia S60 as the RV apical lead plus a coronary sinus LV lead (heart failure indication)

2.4 | Data collection and follow-up

• Baseline characteristics, ECG data and pacing indications collected in a standardised case report form (CRF); procedural characteristics, number of screw attempts, procedural and fluoroscopy times recorded
• Lead implant depth estimated by contrast injections using fluoroscopic landmarks of the Solia S lead to obtain uniform estimates across centres
• Pacing characteristics (thresholds, sensing, impedance) measured at implant and each follow-up. For homogeneity, follow-up data were collected as unipolar pacing threshold at 0.4 ms, bipolar R-wave amplitude, and unipolar pacing impedance
• Clinical, echocardiographic and device follow-up scheduled at 1, 6 and 12 months per local protocols
• LVAT measurement: pacing stimulus to peak R wave in leads V4, V5 or V6 during unipolar pacing

2.5 | Safety endpoints and complications

• Procedural complications defined as: tamponade, pneumothorax, iatrogenic AV block, permanent right bundle branch injury, vascular access complications, pocket haematoma
• Lead-related complications defined as: helix fracture, helix elongation resulting in lead disuse, helix entrapment resulting in an abandoned lead, septal coronary artery fistulas (SCAF), periprocedural lead perforation through the septum
• Perforation suspected during implant if any of three events occurred: sudden decrease in pacing impedance of >200 Ω, high unipolar pacing thresholds >3 V, or leakage of contrast into the left ventricle
• Septal integrity further evaluated on echocardiography by screening for SCAF (diastolic timed colour Doppler jets originating from the septum), septal haematoma and ventricular septal defects before hospital discharge

2.6 | Statistical analysis

• Categorical variables as absolute numbers (percentage); continuous as mean (± SD) if Gaussian, or median [1st and 3rd quartile]/median [range] if non-Gaussian (Shapiro-Wilk test for normality)
• Student t test, Mann-Whitney U and Kruskall Wallis for continuous comparisons; Wilcoxon signed rank and Friedman for paired analysis; Fisher's exact and Chi Square for categorical
• Two-tailed significance level <.05; SPSS version 28.0 (IBM)

3 | Results

3.1 | Patient characteristics

• 353 patients, 43% female, 76 ± 39 years — see the age note in Limitations, as a standard deviation of 39 years is not physiologically possible
• Weight 79 ± 17 kg; length 169 ± 12 cm
• Medical history: coronary artery disease 31%; acute coronary syndrome 10%; atrial fibrillation 43%; heart failure 19% (ischaemic cardiomyopathy 8%, non-ischaemic 11%)
• Baseline ECG: sinus 71%; PR interval 208 ± 59 ms; QRS 122 ± 33 ms; bundle branch block 41% — LBBB 21%, RBBB 16%, IVCD 4%
• Pacing indication: sinus node disease or brady-tachy syndrome 27%; atrioventricular block 63%; heart failure 10%
• Baseline echo: left atrial diameter 43 ± 8 mm; end-diastolic diameter 50 ± 8 mm; end-systolic diameter 35 ± 9 mm; LVEF 53 ± 11%
• Mean follow-up of the overall cohort: 9 ± 5 months

3.2 | Procedural success and characteristics of LBBAP using SDL

• Success was comparable across pacing indications: 95.7% sinus node disease/brady-tachy, 95.2% atrioventricular block, 91.1% heart failure (p = .131)
• LBBAP implant failure with SDL occurred in 19 (5.3%), for four reasons:
  • Inability to reach deep septal position — 6 (1.7%)
  • Pacing thresholds too high — 2 (0.6%)
  • Electrocardiographic criteria for LBBAP not met — 8 (2.2%)
  • Dislocation after slitting — 3 (0.8%)
• Mean procedure and fluoroscopy times were 71 ± 26 and 9 ± 8 min respectively (means, reported alongside the medians above)

3.3 | Electrophysiological and pacing characterization of LBBAP using SDL

• Pacing response labelled LBBP in 244 (73%) of patients — 16% selective, 57% nonselective — and LVSP in 90 (27%)
• QRS duration changes by baseline conduction state — a key table for the LVSP question, since it shows what "success" bought each substrate:

• In patients with baseline narrow QRS the paced QRS was longer than native (95 → 125 ms) — the expected cost of ventricular pacing, unchanged by the LBBAP label
• LBB potentials were recorded in only 48 (14%) of patients — markedly lower than the 50–80% typically cited for lumenless LBBP
• Patients with implant pacing thresholds >1 V: 23 (6.5%); >3 V: 3 (0.8%)
• Pacing thresholds and sensing amplitudes remained stable during follow-up

3.5 | Echocardiographic outcome

• Normal EF at implant: EF remained preserved — 56 ± 3% baseline vs 56 ± 6% with LBBAP, p = .384
• Heart failure indication with reduced EF: EF increased from 28 ± 6% to 40 ± 3%, p < .01
• None of the patients developed de novo heart failure or experienced worsening heart failure — though note this is an uncontrolled observation in a cohort where only 10% had an HF indication

3.4 | Procedural and long-term lead related complications

• Periprocedural septal perforation in 8 (2%) — all remained asymptomatic. In every case the lead was retracted and successfully re-implanted in a different deep septal position. No tamponade occurred related to LBBAP lead placement
• With lead repositioning, severe helix damage occurred in 3 patients resulting in lead disuse. One helix fracture in a deep septal position could not be retrieved
• SCAF detected in 5 (1.4%): 2 detected on contrast injection at implant, 3 on echocardiographic follow-up the day after implant. All 5 remained asymptomatic without signs of cardiac ischaemia or heart failure, and all disappeared at 3-month echocardiography
• No ventricular septal defects or septal haematomas were documented at any echocardiographic follow-up — including in patients with periprocedural perforation and in those with multiple screw attempts
• Overall LBBAP lead revision rate was low: 5 patients (1.4%)
  • Lead dislocation at day 1 in 2 patients, both dislocating to the right ventricle
  • One late septal perforation with dislocation to the left ventricle 3 weeks after implant, causing loss of capture in unipolar configuration. No thrombo-embolic events; the lead was successfully reimplanted in a new deep septal position
  • One patient with dislocation of both atrial and LBBAP leads due to Twiddler's syndrome
  • One LBBAP lead fracture at 7 months, characterised by sudden increase in both unipolar and bipolar impedances (>2000 Ω), noise oversensing and intermittent loss of capture

3.6 | Implant success in low and high-volume centres — the study's key finding

• Median 25 patients implanted per centre (range 5–162)
• Implant success comparable among centres: 97 ± 3%, range 93%–100%, p = .75 — and independent of caseload
• Mean procedural time varied 52 to 95 min and was not related to centre volume
• Mean fluoroscopy time varied 5 to 15 min and was also not related to centre volume

3.x | Pacing characteristics at follow-up (Table 3)

• Threshold stability is the clinical claim being made: 0.6 ± 0.4 V at implant rising only to 0.7 ± 0.3 V at 12 months (p = .291). But only 67 of 353 patients (19%) contribute to the 12-month column

4 | Discussion

4.1 | Main findings

• The study demonstrates feasibility and safety of LBBAP using SDL, and is described as the first and largest multicentre experience of LBBAP using SDL to date. Three main findings:
  1. LBBAP via SDL is associated with a high implant success rate (95%)
  2. Pacing thresholds are low and remain stable at midterm follow-up, with low rates of lead complications
  3. LBBAP using SDL yields similar high implant success rates in both high and low volume centres

4.2 | Current experience with LBBAP using LLL and SDL

• LBBAP preserves normal ventricular activation during ventricular pacing, unlike conventional RVP; thresholds are low and stable, overcoming two important limitations of HBP
• Existing experience was mostly with one LLL (SelectSecure 3830; Medtronic) via a preshaped sheath (C315His or C304). Because LLL lack an inner lumen and a retractable helix mechanism, they benefit from a thin iso-diametric 4.1 Fr body
• SDL differ from LLL in two important features:
  1. The lead body contains an inner lumen for stylet insertion → thicker body, 5.5–6 French versus LLL
  2. SDL often have an extendable helix design, which must be exposed pre-implant and requires measures to remain extended while rotating the lead body in the septal position
• Prior experience with SDL in conduction system pacing is limited. A few studies reported HBP with SDL; Zanon et al. reported two cases of LBBAP using SDL (Solia S) with the Selectra3D sheath. The same group had previously published the first comparison of SDL vs LLL in a small series, showing comparable implant success and acute pacing characteristics
• This study's claim: LBBAP with SDL yields high implant success in a multicentre setting with excellent thresholds and a high safety profile to 1 year. Pacing thresholds, paced QRS duration, LBBAP capture response and procedural characteristics are comparable with previous single and multicentre reports on LBBAP using LLL

4.3 | Safety profile of SDL used for LBBAP

• LBBAP requires the lead to be screwed 10–15 mm deep into the septum to reach the left bundle branch area, depending on septal thickness and lead obliqueness. Because helices of current SDL and LLL are only 1.8–2.0 mm long, a significant part of the distal lead body must be implanted within the septal myocardium
• The a priori concern: SDL have a larger lead body and a non-isodiametric design (at the helix cage), so deep septal positions might be more difficult to achieve. The counter-evidence: high implant success at a mean implant depth of 13 mm shows the lead design and diameter of SDL is not a limitation
• The perforation concern, stated candidly: with the stylet inserted, SDL become stiffer than LLL and might be more prone to perforate through the septum when targeting the left-sided subendocardial septal area. Septal perforations occurred in 2%, but caused no adverse outcome, major complication or persistent septal damage on echocardiography
• The authors acknowledge the rate is higher than a single-centre LLL study, and offer two explanations:
  1. The learning curve with SDL, which requires a training period like any new technique
  2. The first implanted patients were not excluded in this registry, whereas some other LBBAP studies with LLL did exclude their early cases
• They add that continuous unipolar pacing and impedance monitoring on the stylet makes perforation easier to avoid
• On SCAF: a larger lead body and helix might theoretically damage septal structures including septal coronary arteries. SCAF following LBBAP is rarely reported because SCAF are rare, usually asymptomatic, and easily missed without contrast injection or targeted early echocardiography. The low number here despite contrast injections and dedicated echo follow-up in most patients is offered as confirmation of SDL safety
• On the "entanglement effect": the helix of SDL may become tangled in right-sided septal tissue, getting entrapped in subendocardial tissue rather than advancing. Excessive traction can then cause helix elongation, helix fracture, and the need to abandon the lead
  • Only one helix fracture occurred, unretrievable, in the very early learning curve of one centre
  • Across the registry the mean number of screw attempts was 2 per patient — with very few damaged helices, indicating that repositioning SDL generally does not lead to helix damage
  • Management: gentle alternating clockwise and counter-clockwise rotations of the lead body — without actively retracting the helix and without releasing the build-up torque — allow easy removal of the entangled lead in the vast majority of cases

4.4 | Advantages and disadvantages of SDL used for LBBAP

• Five properties that make SDL well suited to deep septal targeting:
  1. Larger lead calibre allows excellent grip when applying rotations on the outer lead body
  2. With the stylet inserted, maneuverability (torque and push) is exemplary and facilitates progression into the septum without excessive risk of perforation
  3. The stylet adds stability on the septum when mapping and screwing
  4. Impedance monitoring is easily achieved by connecting the pacing clamp to the stylet, allowing continuous pacing and impedance monitoring while screwing
  5. The delivery sheaths for SDL have a larger diameter and are more supportive than those used with LLL
• The disadvantage: with extendable helices, helix unwinding might occur when rotating the outer lead body — though with appropriate preparation, helix retraction can easily be avoided. The low number of lead dislocations confirms the stability of SDL in deep septal position
• Future perspective: a lead design combining the properties of current SDL with a fixed helix might further improve LBBAP success

4.5 | Limitations (authors' own — see also the section below)

• Successful LBBAP was defined as both LBBP and LVSP, which differs from other LBBAP reports where only proven conduction system capture was accepted as a successful final position
• Most operators were certified electrophysiologists with large (>5 years) experience implanting cardiac implantable electronic devices. Care should be taken extrapolating these results to starting implanters without electrophysiology experience
• One type of SDL (Solia S60) and one type of delivery sheath (Selectra3D) were used; other SDL with different sheaths might behave differently
• No long-term data (>1 year) on pacing performance or extractability of LBBAP leads

5 | Conclusion

• LBBAP with SDL is associated with high implant success, stable pacing characteristics and low complication rates in this large multicentre registry
• The observations suggest LBBAP can be performed safely with a variety of standard pacing leads, which might contribute to wider implementation of LBBAP as a new pacing modality

Limitations of the document

Authors' own stated limitations

• The success definition is composite and looser than the comparator literature — LBBAP success was defined as LBBP or LVSP, whereas other reports accepted only proven conduction system capture. Since 27% of this cohort was LVSP, roughly a quarter of the headline 94.6% success describes pure myocardial pacing, not conduction system capture. Success rates here are therefore not directly comparable with lumenless-lead series, and the paper does not attempt to re-report them separately
• Operator experience is a major unaddressed confounder for the volume-independence claim. The authors state most operators were certified electrophysiologists with >5 years of device experience. The finding that success was independent of centre volume therefore shows that experienced operators succeed regardless of how many LBBAP cases they have done — it does not show that a low-volume or non-electrophysiologist implanter would. The authors flag this, but the discussion's framing ("easy to use and promising") reaches somewhat further than the design supports
• Single lead, single sheath (Solia S60 + Selectra3D). Generalisability to other SDL — particularly those without an inner lumen enabling stylet pacing, or different sheath curves — is asserted rather than tested
• No long-term data beyond 1 year; extractability is entirely unstudied, which matters for a lead deliberately placed deep in the septum

Additional limitations evident in the study

• No control group and no randomisation. Every comparison to lumenless leads is cross-study and historical, including the central safety comparison (2% perforation "slightly higher than" a single-centre LLL study). Differences in operator skill, case mix, era, contrast use and echo surveillance all bear on that comparison, and the paper adjusts for none of them
• The 12-month pacing data rests on 67 of 353 patients (19%), and the 6-month data on 259 (73%). Threshold stability at 12 months (p = .291) is therefore a claim about a self-selected fifth of the cohort — plausibly the healthiest and those with the best leads, since patients with revised or abandoned leads would not contribute. The p value is reported without any survival or competing-risk framing, and mean follow-up is only 9 ± 5 months
• "Success" was adjudicated by the implanting physician, not a core laboratory. Acceptance of the final lead position was explicitly "left to the discretion of the implanting physician", and capture type (LBBP vs LVSP) rests on ECG criteria applied at the bedside. There is no independent adjudication, no blinded review, and — importantly — the LBB potential, the most specific marker of actual left bundle capture, was recorded in only 14%, far below the 50–80% typical of lumenless LBBP series
• The composite "success" endpoint cannot distinguish a lead that captured the conduction system from one that merely paced septal myocardium, so the registry's 94.6% and MELOS's 92.4% are measuring different things. That the study reports the components (57/16/27%) is a strength, but it never presents success rates restricted to LBBP
• Implant depth was estimated, not measured — "estimated by contrast injections and based on the fluoroscopic landmarks of the Solia S lead", a method the authors designed to obtain uniform estimates, but which has no stated validation or inter-observer reproducibility
• The EF improvement in heart failure (28 ± 6% → 40 ± 3%) has no control arm and is small (10% of the cohort, n≈34). Regression to the mean, and the selection of patients who survived to follow-up echocardiography, both plausibly contribute. The companion claim that no patient developed de novo or worsening heart failure is likewise uncontrolled and, given 43% had AF and most had preserved EF, a relatively low bar
• Two internal numerical inconsistencies and one impossible statistic appear in the paper:
  • Age is reported as 76 ± 39 years in both the abstract and Table 1. A standard deviation of 39 years would span roughly −2 to 154 years and is physiologically impossible; the true dispersion is presumably about ±13 years. It is reproduced in the paper's own two locations, so it is not an extraction error from this ingest
  • Implant success is reported as 94% (abstract), 94.6% (text) and 95% (Table 2) for the same 334/353 numerator. Each is defensible rounding, but reporting three values for one figure invites confusion and the abstract's "94%" is the only one that reads as a distinct number
  • The paper's section numbering runs 3.1, 3.2, 3.3, 3.4, 3.6, 3.5 in the source, with "3.6 | LBBAP implant success using SDL in low and high-volume centers" placed before "3.5 | Echocardiographic outcome" (and the echocardiographic heading appears after the 4 | DISCUSSION heading in the extracted text). The content is intact; the ordering is the paper's own
• Complications are reported as raw counts with no denominator adjustment for follow-up duration or for multiple events per patient, and there is no prespecified primary safety endpoint — so "low complication rates" is a qualitative reading of an unpowered count
• Rating rationale: a prospective, consecutively enrolled, multicentre registry with a genuinely new and clinically useful finding (volume-independence) and detailed complication reporting — but uncontrolled, single-device, self-adjudicated, with a composite endpoint that overstates conduction-system capture and 12-month data on 19% of the cohort. Stronger than a small single-centre feasibility study, weaker than MELOS's 2,533-patient multicentre registry — hence medium

Key Concepts Mentioned

• concepts/Left-Bundle-Branch-Area-Pacing — the technique under study; this paper is the largest multicentre evidence for the stylet-driven-lead route to it
• concepts/Conduction-System-Pacing — the umbrella category
• concepts/His-Bundle-Pacing — the comparator modality whose limitations (high thresholds, low sensing, low success in infranodal disease) motivated the shift to LBBAP
• Stylet-driven pacing leads (SDL) vs lumenless leads (LLL) — the paper's organising contrast: SDL 5.5–6 Fr with an inner stylet lumen and an extendable helix, versus the 4.1 Fr iso-diametric fixed-helix SelectSecure 3830
• Left bundle branch pacing (LBBP) vs left ventricular septal pacing (LVSP) — the capture distinction; 73% vs 27% here, and the reason the 94.6% success figure is not comparable with capture-only series
• Stimulus to LVAT (left ventricular activation time) — the interval from pacing stimulus to R-wave peak in V4–V6; 74 ± 17 ms here, and the capture criterion with the <80 ms / <100 ms output-dependent cut-offs
• Septal perforation — 2% here, above the lumenless literature; detected by impedance fall >200 Ω, threshold >3 V, or contrast leak into the LV
• Septal coronary artery fistula (SCAF) — 1.4%; defined by diastolic timed colour Doppler jets from the septum; all resolved by 3 months
• Helix entanglement and retraction — the SDL-specific failure mode (entrapment in subendocardial tissue rather than septal advancement), and the pretensioning preparation designed to prevent it

Key Entities Mentioned

• concepts/Left-Bundle-Branch-Area-Pacing — primary concept page
• Biotronik Solia S60 — the stylet-driven lead studied (5.6 Fr, extendable helix); also the lead in sources/impedance-lbbap-jce-2022
• Biotronik Selectra3D — the dedicated delivery sheath used; the same sheath as in the Zanon case reports
• Medtronic SelectSecure 3830 — the lumenless lead that dominates the comparator literature (4.1 Fr, fixed helix), with C315His/C304 sheaths
• Medtronic, Biotronik, Boston Scientific, Abbott, St Jude Medical, Microport — disclosed industry relationships across the author list; Biotronik manufactures both the lead and the sheath studied
• Eight Belgian centres — University Hospital Ghent (coordinating), OLV Aalst, Cliniques Universitaire Saint-Luc Louvain, AZ Maria Middelares Ghent, AZ Delta Roeselare, Citadelle Château Rouge Liège, AZ Sint Jan Brugge, Clinique Saint Pierre Ottignies; plus University of Arizona College of Medicine-Phoenix
• Wiley Periodicals — publisher (J Cardiovasc Electrophysiol)

Wiki Pages Updated

• Created: wiki/sources/stylet-lbbap-jce-2022.md
• Updated: wiki/concepts/Left-Bundle-Branch-Area-Pacing.md
• Updated: wiki/concepts/Conduction-System-Pacing.md
• Updated: wiki/sourceindex.md
• Updated: wiki/wikiindex.md