B-PO01-030 DEEP SEPTAL PACING WITH RAPID LEFT VENTRICULAR ACTIVATION: A SIMPLIFIED APPROACH WITHOUT CONDUCTION SYSTEM TARGETING

Background: Left bundle branch area pacing (LBBAP) has recently been introduced as a novel physiological pacing strategy. Within LBBAP, distinction is made between left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP, no left bundle capture). Objective: To investigate acute electrophysiological effects of LBBP and LVSP as compared to intrinsic ventricular conduction. Methods: Fifty patients with normal cardiac function and pacemaker indication for bradycardia underwent LBBAP. Electrocardiography (ECG) characteristics were evaluated during pacing at various depths within the septum: starting at the right ventricular (RV) side of the septum: the last position with QS morphology, the first position with r’ morphology, LVSP and—in patients where left bundle branch (LBB) capture was achieved—LBBP. From the ECG’s QRS duration and QRS morphology in lead V1, the stimulus- left ventricular activation time left ventricular activation time (LVAT) interval were measured. After conversion of the ECG into vectorcardiogram (VCG) (Kors conversion matrix), QRS area and QRS vector in transverse plane (Azimuth) were determined. Results: QRS area significantly decreased from 82 ± 29 µVs during RV septal pacing (RVSP) to 46 ± 12 µVs during LVSP. In the subgroup where LBB capture was achieved (n = 31), QRS area significantly decreased from 46 ± 17 µVs during LVSP to 38 ± 15 µVs during LBBP, while LVAT was not significantly different between LVSP and LBBP. In patients with normal ventricular activation and narrow QRS, QRS area during LBBP was not significantly different from that during intrinsic activation (37 ± 16 vs. 35 ± 19 µVs, respectively). The Azimuth significantly changed from RVSP (−46 ± 33°) to LVSP (19 ± 16°) and LBBP (−22 ± 14°). The Azimuth during both LVSP and LBBP were not significantly different from normal ventricular activation. QRS area and LVAT correlated moderately (Spearman’s R = 0.58). Conclusions: ECG and VCG indices demonstrate that both LVSP and LBBP improve ventricular dyssynchrony considerably as compared to RVSP, to values close to normal ventricular activation. LBBP seems to result in a small, but significant, improvement in ventricular synchrony as compared to LVSP.

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What is the mechanism of narrow paced QRS duration during left bundle branch area pacing? A case report

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytaa239 ◽

2020 ◽

Vol 4 (4) ◽

pp. 1-5

Author(s):

Yusuke Hayashi ◽

Kenji Shimeno ◽

Kenichi Nakatsuji ◽

Takahiko Naruko

Keyword(s):

Case Report ◽

Three Dimensional ◽

Left Ventricular ◽

Conduction System ◽

Conduction Time ◽

Activation Time ◽

Activation Patterns ◽

Stimulus Interval ◽

Ventricular Activation ◽

Qrs Duration

Abstract Background Although left bundle branch area pacing (LBBAP) can capture the His-Purkinje conduction system and create a narrower paced QRS duration, its mechanism has not been investigated. In this case report, ventricular activation patterns were evaluated using three-dimensional electroanatomical mapping during LBBAP and right ventricular septal pacing (RVSP). Case summary An 81-year-old woman with sick sinus syndrome received LBBAP, followed 4 months later with atrial fibrillation ablation. We compared ventricular activation patterns during RVSP and LBBAP using a three-dimensional electro-anatomical mapping system. Paced QRS durations during RVSP and LBBAP were 163 ms and 115 ms, respectively. The activation pattern and the total left ventricular (LV) activation time were similar during RVSP and LBBAP (86 and 73 ms, respectively), despite the conduction system capture during LBBAP. The stimulus interval to the latest LV activation point during RVSP was 117 ms, and transseptal conduction time was 31 ms (117 − 86 ms). Discussion Although LBBAP could capture the His-Purkinje conduction system, neither ventricular activation patterns nor total activation time changed dramatically. The mechanism of narrower paced QRS duration during LBBAP compared to that during RVSP can be attributable to passing over the slow transseptal conduction.

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Physiology and Practicality of Left Ventricular Septal Pacing

Arrhythmia & Electrophysiology Review ◽

10.15420/aer.2021.21 ◽

2021 ◽

Vol 10 (3) ◽

pp. 165-171

Author(s):

Luuk Heckman ◽

Justin Luermans ◽

Floor Salden ◽

Antonius Martinus Wilhelmus van Stipdonk ◽

Masih Mafi-Rad ◽

...

Keyword(s):

Animal Studies ◽

Left Ventricular ◽

Lv Function ◽

Free Wall ◽

Long Term Effects ◽

Intraventricular Dyssynchrony ◽

Septal Pacing ◽

Ventricular Activation ◽

Patient Studies

Left ventricular septal pacing (LVSP) and left bundle branch pacing (LBBP) have been introduced to maintain or correct interventricular and intraventricular (dys)synchrony. LVSP is hypothesised to produce a fairly physiological sequence of activation, since in the left ventricle (LV) the working myocardium is activated first at the LV endocardium in the low septal and anterior free-wall regions. Animal studies as well as patient studies have demonstrated that LV function is maintained during LVSP at levels comparable to sinus rhythm with normal conduction. Left ventricular activation is more synchronous during LBBP than LVSP, but LBBP produces a higher level of intraventricular dyssynchrony compared to LVSP. While LVSP is fairly straightforward to perform, targeting the left bundle branch area may be more challenging. Long-term effects of LVSP and LBBP are yet to be determined. This review focuses on the physiology and practicality of LVSP and provides a guide for permanent LVSP implantation.

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Direct capture of the left bundle branch compared to left bundle branch area pacing deteriorates interventricular synchrony but improves left ventricular lateral wall depolarization duration

EP Europace ◽

10.1093/europace/euab116.396 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

K Curila ◽

P Jurak ◽

P Waldauf ◽

J Halamek ◽

J Karch ◽

...

Keyword(s):

Lateral Wall ◽

Left Ventricular ◽

Public Institution ◽

Research Centre ◽

Direct Capture ◽

Funding Sources ◽

Lead Placement ◽

Septal Pacing ◽

Ventricular Activation ◽

Ventricular Depolarization

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): This paper was supported by the Charles University Research Centre program No. UNCE/MED/002 and 260530/SVV/2020 Background Direct and indirect pacing of the left bundle branch are novel pacing techniques preserving LV synchrony. Aim of the study was to compare differences in ventricular activation between them using an UHF-ECG. Methods The left septal lead placement was done in 68 patients with bradycardia. Four distinct ventricular captures were described; nonselective LBBp (nsLBBp), selective LBBp (sLBBp), paraLBBp and left bundle branch area capture (LBBap). The timings of local ventricular activations and local depolarization durations were displayed by the UHF-ECG. e-DYS was calculated as a difference between the first and last activation. Results There were 35 nsLBBp, 21 paraLBBp, 12 sLBBp and 96 LBBap obtained in 68 patients. The nsLBBp compared to LBBap caused worse interventricular synchrony (e-DYS -23 ms (-28;-18) vs -12 ms (-17;-8), p < 0.001), but improved LV lateral wall depolarization duration. The sLBBp, nsLBBp and paraLBBp differed in e-DYS; -31 ms (-38;-24) vs -23 ms (-28;-17) vs -13 ms (-20;-7), p < 0.01 between each of them. Their left ventricular depolarization durations were the same, but they were longer when pacing resulted in the left axis deviation. If the direct capture of the LBB was not confirmed (LBBap), LV depolarization duration was deteriorated irrespective of the QSR morphology in the V1 or RWPT in the V5. Examples of UHF-ECG maps during LBBap, paraLBBp and nsLBBp are shown in Figure 1. Conclusions The direct capture of the left bundle branch deteriorates interventriclar synchrony but improves the depolarization duration of the left ventricular lateral wall compared to left ventricular myocardial septal pacing. Abstract Figure 1

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Bilateral Bundle Branch Area Pacing to Achieve Physiological Conduction System Activation

Circulation Arrhythmia and Electrophysiology ◽

10.1161/circep.119.008267 ◽

2020 ◽

Vol 13 (8) ◽

Author(s):

Jinxuan Lin ◽

Keping Chen ◽

Yan Dai ◽

Qi Sun ◽

Yuqiu Li ◽

...

Keyword(s):

Right Ventricular ◽

Right Bundle Branch Block ◽

Left Ventricular ◽

Conduction System ◽

Conduction Delay ◽

Activation Time ◽

Bundle Branch Block ◽

Ventricular Activation ◽

Qrs Duration ◽

The Right

Background: Left bundle branch pacing (LBBP) is a technique for conduction system pacing, but it often results in right bundle branch block morphology on the ECG. This study was designed to assess simultaneous pacing of the left and right bundle branch areas to achieve more synchronous ventricular activation. Methods: In symptomatic bradycardia patients, the distal electrode of a bipolar pacing lead was placed at the left bundle branch area via a transventricular-septal approach. This was used to pace the left bundle branch area, while the ring electrode was used to pace the right bundle branch area. Bilateral bundle branch area pacing (BBBP) was achieved by stimulating the cathode and anode in various pacing configurations. QRS duration, delayed right ventricular activation time, left ventricular activation time, and interventricular conduction delay were measured. Pacing stability and short-term safety were assessed at 3-month follow-up. Results: BBBP was successfully performed in 22 of 36 patients. Compared with LBBP, BBBP resulted in greater shortening of QRS duration (109.3±7.1 versus 118.4±5.7 ms, P <0.001). LBBP resulted in a paced right bundle branch block configuration, with a delayed right ventricular activation time of 115.0±7.5 ms and interventricular conduction delay of 34.0±8.8 ms. BBBP fully resolved the right bundle branch block morphology in 18 patients. In the remaining 4 patients, BBBP partially corrected the right bundle branch block with delayed right ventricular activation time decreasing from 120.5±4.7 ms during LBBP to 106.1±4.2 ms during BBBP ( P =0.005). Conclusions: LBBP results in a relatively narrow QRS complex but with an interventricular activation delay. BBBP can diminish the delayed right ventricular activation, producing more physiological ventricular activation. Graphic Abstract: A graphic abstract is available for this article.

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Novelties in cardiac pacing. Left bundle branch pacing, a step-by-step guide

In a good rythm ◽

10.5604/01.3001.0015.4536 ◽

2021 ◽

Vol 2 (59) ◽

pp. 27-41

Author(s):

Marek Jastrzębski

Keyword(s):

Cardiac Pacing ◽

Left Ventricular ◽

Conduction System ◽

Target Area ◽

His Bundle ◽

His Bundle Pacing ◽

Septal Pacing ◽

Rotation Technique ◽

Ventricular Activity ◽

Pace Mapping

Left bundle branch pacing (LBBP) technique is a new method for conduction system pacing that is useful for both bradyarrhythmia and heart failure indications. LBBP, while less physiological than His bundle pacing, offers several practical advantages. Namely, lower and stable pacing thresholds, good sensing of the intrinsic ventricular activity and easiness in localizing the pacing target. The LBBP method more often than His bundle pacing results in engagement of the conduction system distal to the area of the block. A step-by-step approach to LBBP was described. Attention was given to the following phases of the procedure: 1) localization of the target area on the septum, 2) the lead rotation technique with an interpretation of the lead responses (drill effect, screwdriver effect, entanglement effect), 3) methods for monitoring the lead depth in the septum to avoid perforation (fixation beats, continuous pace mapping, impedance), and 4) methods to differentiate between LBBP and left ventricular septal pacing.

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Comparison of QRSarea and left ventricular activation time during left bundle branch pacing and left ventricular septal pacing

EP Europace ◽

10.1093/europace/euab116.390 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

LIB Heckman ◽

JGK Luermans ◽

K Curila ◽

AMW Van Stipdonk ◽

S Westra ◽

...

Keyword(s):

Left Ventricular ◽

Funding Sources ◽

Septal Pacing ◽

Ventricular Activation ◽

Intrinsic Conduction ◽

Qrs Morphology ◽

Conversion Matrix ◽

Qrs Duration ◽

Normal Cardiac Function ◽

Funding Acknowledgements

Abstract Funding Acknowledgements Type of funding sources: None. Background Left bundle branch area pacing (LBBAP) has recently been introduced as a novel physiological pacing strategy. Within LBBAP, distinction is made between left bundle branch pacing (LBBP) and left ventricular septal pacing (LVSP, no left bundle capture). Objective To compare acute electrocardiographic (ECG) and vectorcardiographic (VCG) effects of LBBP and LVSP as compared to intrinsic conduction. Methods In 50 patients with normal cardiac function and pacemaker indication for bradycardia, ECG characteristics of LBBP and LVSP were evaluated during RVSP and pacing at various depths in the septum: starting at the RV side of the septum: the last position with QS morphology, the first position with r’ morphology, LVSP and – in patients where LBB capture was achieved – LBBP. From the ECG’s QRS duration and QRS morphology in V1, and the stimulus-LVAT interval were measured. After conversion of the ECG into VCG (Kors conversion matrix), QRS area was calculated. Results In LVSP, QRS area significantly decreased from 82 ± 29 µVs during RVSP to 46 ± 12 µVs during LVSP. In patients where LBB capture was achieved QRS area significantly decreased from 78 ± 23 µVs to 38 ± 15 µVs in LBBP. In patients with LBB capture, QRS area was significantly smaller during LBBP compared to LVSP (figure A), but LVAT was not significantly different (figure B, p = 0.138). In patients with normal ventricular activation where LBBP was achieved (n = 20), QRS area was significantly larger during LVSP (48 ± 17) compared to LBBP (37 ± 16), the latter being not significantly different from normal intrinsic ventricular activation (35 ± 19 µVs). Conclusions ECG and VCG indices demonstrate that ventricular dyssynchrony is comparable but slightly more synchronous during LBBP compared to LVSP. Abstract Figure. QRS area and S-LVAT in LVSP and LBBP

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