Permanent His Bundle Pacing Research Articles

His bundle pacing. Technical aspects and evidence base for use as an alternative to cardiac resynchronization therapy and conventional electrical pacing

His bundle pacing is a direct pacing of the specialized His-Purkinje conduction system with the aim of physiological ventricular activation, in contrast to the dyssynchronous activation by conventional myocardial pacing.In this review article on His-Purkinje conduction system pacing, the authors evaluate the available data and current practice, and assess emerging and future directions in this fast growing area. We analyzed the available publications on His bundle and conduction system pacing.Since the first report of permanent His-bundle pacing (HBP) in 2000, the earliest incarnation of stylet-driven technique has been replaced by the more effective non-stylet-driven approach. Widespread adoption has generated a large evidence base. Single-center observational studies have been complemented by large multicenter international registries, mechanistic studies, and the first randomized controlled trials. New data have clarified the mechanisms of РИЗ and illustrated the nature and extent of its potential benefits in preventing pacing cardiomyopathy and correcting bundle branch block.Conduction system stimulation is the most physiological type of cardiac pacing in patients with a narrow QRS complex. Conduction system pacing may be an effective alternative to biventricular pacing in cardiac resynchronization therapy. Randomized controlled trials are needed to expand the evidence base.

His bundle pacing is continually relevant for patients with atrial fibrillation and bradycardia without prior atrioventricular nodal ablation, data from mid-term follow-up.

In patients with atrial fibrillation (AF) and symptomatic bradycardia, His Bundle pacing (HBP) is used to achieve an appropriate heart rate and physiological depolarization of the left ventricle (LV). We aimed to evaluate the impact of HBP on LV function in two different populations: normal LV ejection fraction (LVEF) and low LVEF (<50%). Patients who received HBP as de novo therapy or as an upgrade were divided into two groups based on initial LVEF, followed by echocardiographic and device monitoring. One hundred and twenty three patients (aged 76.0 [69.2-79.8] years, 74.0% men) with AF and bradycardia received HBP and completed follow-up with a median of 6.2 months (6.0-8.0). LV function remained unchanged in initially normal LV function patients (65 participants, LVEF 59.0% [55.0 - 62.0] vs. 58.0% [55.0-63.0]). In patients with low LVEF (58 participants), there was an increase in LVEF (37.5% [30.0-43.0] vs. 44.0% [35.0-50.0]; p < 0.0001), reduction of indexed LV end-systolic volume (62.4 [20.7] ml vs. 51.5 [21.5] ml; p = 0.001) and indexed LV end-diastolic volume (97.5 [26.2] ml vs. 88.1 [25.1] ml; p = 0.009), and improvement in the New York Heart Association class (2.3 [0.71] to 1.6 [0.9]; p < 0.0001). With permanent HBP, patients with AF and bradycardia and without prior atrioventricular nodal ablation did not experience LV systolic function deterioration. Those with reduced baseline LVEF experienced improvements in LV function and its reverse remodeling at the mid-term follow-up.

An abrupt loss of capture during permanent His-bundle pacing: Assessment of mechanism underlying late capture threshold rise.

A His-bundle (HB) capture threshold rise is still a significant concern in permanent His-bundle pacing (HBP). We present a case where an abrupt increase in HB threshold and loss of capture occurred even after 3.5 years of stable permanent HBP for an atrioventricular block. The development of local fibrosis around the lead helix and the change in an insertion angle of the lead might adversely affect the HB capture threshold in the chronic phase.

His bundle pacing in nodal versus infranodal atrioventricular block: a mid-term follow-up study

IntroductionThis study evaluated the feasibility of His bundle pacing (HBP) in consecutive, unselected patients with advanced atrioventricular block (AVB) over a medium-term follow-up period, comparing procedural characteristics between nodal and...

Permanent His bundle pacing in patients with right atriomegaly: The value of different dedicated delivery sheaths.

An enlarged right atrium (RA) is a challenging anatomy that can limit the successful use of His bundle pacing (HBP). It is unknown whether new implantation tools could help overcome these challenges. Consecutive patients with RA volume index >25mL/m2 in men and >21mL/m2 in women underwent permanent HBP. We used a stylet-driven lead (SDL) with an extendable helix delivered via a dedicated delivery sheath (Selectra 3D, Biotronik) as a first attempt. In case of failure, a second attempt was performed with the same lead but with a different delivery curve. Finally, a lumen-less lead (LLL) was also available as a third attempt. The study cohort included 24 patients (median age 75.7 years [interquartile range, 70.9-79.0], 88% men) with a RA volume of 49mL/m2 (45-54). Using SDL, HBP was achieved with a single sheath curve in 17 patients (71%). The second attempt with the same lead but a different sheath was successful in four more patients (SDL success 87%). The fluoroscopy time increased significantly when the second attempt was necessary (8min [6-11] vs. 15min [13-17], p<.001). In the remaining three patients, HBP was further attempted with a LLL leading to a final procedural success of 96%. No lead dislodgment nor significant increase in pacing threshold was observed at 1-month (1.2 [0.7-1.7] V@1.0ms vs. 1.1 [0.8-1.7] V@1.0ms, p=.939). The availability of different dedicated delivery systems for HBP can improve procedural outcomes even in challenging circumstances, such as in patients with right atriomegaly.

The Impact of Cardiac Chamber Volumes on Permanent His Bundle Pacing Procedural Outcomes-A Single Center Experience.

His bundle pacing (HBP) has several pitfalls, such as the inability to identify the His bundle and lack of capture at acceptable thresholds. The majority of data regarding HBP were obtained using a dedicated non-deflectable delivery system. This study aimed to evaluate the impact of cardiac chamber dimensions on permanent HBP procedural outcomes when using this type of fixed-curve catheter. Seventy-two patients subjected to HBP from the 1st of January to the 31st of December 2021 at our institution were retrospectively reviewed. The baseline clinical characteristics and echocardiographic measurements of all the cardiac chambers were recorded, as well as procedural outcomes (HB electrogram identification and overall procedural success). During the procedure, the HB electrogram was recorded in 59 patients (81.9%) and successful permanent HBP was achieved in 33 patients, representing 45.8% of all the studied patients. Left atrial (LA) and right atrial (RA) volumes were significantly higher in patients without HB electrogram identification. Only LA and RA volumes were statistically associated with HB electrogram localization, while there was no significant association between the echocardiographic parameters and procedural success. LA volumes above 93 mL and RA volumes above 60 mL had an 8.81 times higher chance of failure to localize the HB electrogram compared with patients with lower volumes (p < 0.001). When considering non-deflectable delivery catheters for HBP, careful preprocedural echocardiographic analysis of the atrial volumes could help in the proper selection of implanting tools, thus optimizing the procedural outcomes and costs.

Left Bundle Branch Pacing Postatrioventricular Junction Ablation for Atrial Fibrillation: Propensity Score Matching With His Bundle Pacing.

Left bundle branch pacing (LBBP) has emerged as a promising pacing modality to preserve physiological left ventricular activation; however, prospective data evaluating its long-term safety and efficacy in pacemaker-dependent patients following atrioventricular junction (AVJ) ablation are lacking. This study aimed to examine the feasibility, safety, and efficacy of LBBP in patients with atrial fibrillation and heart failure (HF) after AVJ ablation and compare LBBP with His bundle pacing (HBP) through a propensity score (PS) matching analysis. We prospectively enrolled patients with atrial fibrillation and HF referred for AVJ ablation and LBBP between July 2017 and December 2019. The control group was patients selected from HBP implants performed from 2012 to 2019 using PS matching with a 1:1 ratio. A total of 99 patients were enrolled in the study. The LBBP implant success rate was 100%. Left ventricular ejection fraction improved from baseline 30.3±4.9 to 1-year 47.3±14.5 in HF patients with reduced ejection fraction and from baseline 56.3±12.1 to 1-year 62.3±9.1 in HF patients with preserved ejection fraction (both P<0.001), and left ventricular ejection fraction in both groups remained stable for up to 3 years of follow-up. A threshold increase >2 V at 0.5 ms occurred in only one patient. Of 176 (81.9%) of 215 patients who received permanent HBP post-AVJ ablation, 86 were matched to the LBBP group by 1:1 PS (propensity score matched His bundle pacing, N=86; propensity score matched left bundle branch pacing, N=86). No significant differences in echocardiographic or clinical outcomes were observed between the 2 groups (P>0.05), whereas lower thresholds, greater sensed R-wave amplitudes, and fewer complications were observed in the propensity score matched left bundle branch pacing group (P<0.05). LBBP is feasible, safe, and effective in patients with atrial fibrillation and HF post-AVJ ablation and has similar clinical benefits, a higher implant success rate, better pacing parameters, and fewer complications compared with HBP.

A single-centre experience of His bundle pacing without electrophysiological mapping system: implant success rate, safety, pacing characteristics and one-year follow up.

Despite the challenges related to His bundle pacing (HBP), recent data suggest an improved success rate with experience. As a non-university, non-electrophysiology specialised centre in Singapore, we report our experiences in HBP using pacing system analyser alone. Data of 28 consecutive patients who underwent HBP from August 2018 to February 2019 was retrospectively obtained. The clinical and technical outcomes of these patients were compared between two timeframes of three months each. Patients were followed up for 12 months. Immediate technical success was achieved in 21 (75.0%) patients (mean age 73.3 ± 10.7 years, 47.6% female). The mean left ventricular ejection fraction was 53.9% ± 12.1%. The indications for HBP were atrioventricular block (n = 13, 61.9%), sinus node dysfunction (n = 7, 33.3%) and upgrade from implantable cardioverter-defibrillator to His-cardiac resynchronisation therapy (n = 1, 4.8%). No significant difference was observed in baseline characteristics between Timeframe 1 and Timeframe 2. Improvements pertaining to mean fluoroscopy time were achieved between the two timeframes. There was one HBP-related complication of lead displacement during Timeframe 1. All patients with successful HBP achieved non-selective His bundle (NSHB) capture, whereas only eight patients had selective His bundle (SHB) capture. NSHB and SHB capture thresholds remained stable at the 12-month follow-up. Permanent HBP is feasible and safe, even without the use of an electrophysiology recording system. This was successfully achieved in 75% of patients, with no adverse clinical outcomes during the follow-up period.

New right bundle branch block after selective HIS bundle pacing, Two methods for correction

HIS Bundle Pacing (HBP) is considered the most physiologic pacing technique as it generates a physiological activation of both ventricles through synchronous ventricular depolarization of His bundle– Purkinje conduction system. Permanent HBP and Atrioventricular Node (AVN) ablation in patients with heart failure and atrial fibrillation were found to have an improvement in cardiac function and reduction of left ventricular dimensions [1]. We present case of paroxysmal atrial fibrillation and atypical atrial flutter that underwent HBP and AVN ablation. The patient developed a Right Bundle Branch Block (RBBB) following his AVN ablation with widening of QRS duration to 148 msec. We managed to correct this and restore a narrow QRS by two different mechanisms: 1. Programming the Interventricular (VV) delay to 20 msec (His pacing first followed by septal RV pacing through a back-up lead, 2. Unipolar pacing of the HIS lead with different configuration. By both methods, QRS duration was reduced to 108-110 msec with restoration of physiologic biventricular pacing. To the best of our knowledge, this has not been reported before. Keywords: atrial fibrillation; his bundle pacing; ablate; pace.

Permanent His-bundle pacing in the right atrium in a patient with a Mobitz II atrioventricular block: a case presentation

BackgroundThis case report presents a patient diagnosed with sick sinus syndrome who was successfully treated with permanent His-bundle pacing (PHBP).Case presentationA 36-year-old man was transferred to our hospital due to recurrent syncope. He was diagnosed with sick sinus syndrome based on the 24-h Holter and a history of syncope. He was admitted to hospital and successfully treated with PHBP. The postoperative examination showed that the pacing rhythm, pacemaker pacing and perception function were normal. He was discharged without any complications after a successful pacemaker implantation.ConclusionsWe described a case in which PHBP may become an optimal approach to the management of patients with sick sinus syndrome. Right ventricular pacing has been attempted with inconsistent efficacy outcomes. HBP provides a promising alternative pacing option that might provide symptom resolution to patients with sick sinus syndrome.

Can permanent His Bundle Pacing be safely started by operators new to this technique? Data from a multicenter registry

Can permanent His Bundle Pacing be safely started by operators new to this technique? Data from a multicenter registry

Efficacy of His Bundle Pacing on LVRelaxation and Clinical Improvement in HFandLBBB.

Efficacy of His Bundle Pacing on LVRelaxation and Clinical Improvement in HFandLBBB.

His bundle pacing: initial Slovenian single-centre experience

Background: High right ventricular (RV) pacing burden may promote left ventricular dysfunction. Recently, His bundle pacing (HBP) has emerged as an alternative method to RV pacing that provides physiological ventricular activation by directly stimulating the conduction system.&#x0D; Methods: Consecutive 75 patients (male 61.3%, age 65 ± 14 yrs, preserved ejection fraction 53.8%, atrial fibrillation (AF) 56%) in whom HBP was attempted at our centre between May 2018 and September 2020 were included. Acute implant success rate, complications and mid-term outcomes were assessed.&#x0D; Results: Permanent HBP was acutely successful in 69 patients (92%). There were no acute procedure-related complications. Most common indication was AF with rapid ventricular response (38.7%) where HBP was performed in conjunction with atrioventricular node ablation. Median fluoroscopy time was lower during the second half of implants (6.35 (2.7 – 47) vs. 5.4 (1.3 – 13.6) minutes; p = 0.004). His capture parameters remained stable during the median follow-up of 193 (59 – 342) days. Eleven patients (11/69, 15.9%) with initially successful procedure experienced a significant rise in HBP threshold. Three patients (3/69, 4.3%) needed HBP lead revision or deactivation.&#x0D; Conclusion: Our initial experience indicates that HBP is feasible and safe in various pacing indications. Further randomized clinical trials with long-term follow-up are needed to provide the grounds for wider clinical application of this promising physiological pacing technique.

Abstract 11706: His Bundle Pacing and Atrioventricular Nodal Ablation in the Management of Refractory Atrial Fibrillation, a Systematic Review and Meta-Analysis

Introduction: Ventricular rate control is critical in management of atrial fibrillation (AF). When pharmacologic therapy fails in controlling the ventricular rate, atrioventricular nodal ablation (AVNA) and pacing is considered an effective therapy for symptomatic management. His bundle pacing (HBP) is considered a physiologic mode of pacing with AVNA ensuring synchronized activation of right and left ventricles preserving ventricular functioning. Hypothesis: HBP and AVNA are feasible, safe, and effective for management of refractory AF. Methods: We identified 218 studies after literature review of EMBASE, Medline, and Cochrane databases. Our analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Results: Six studies (two randomized controlled trials, four observational cohorts) were included in the final meta-analyses. A total of 275 patients underwent attempted permanent HBP and AVNA. The mean age of patients was 70.74 (SD 4.38; 95% CI 62.15-79.32). Mean implant success rate for acute HBP was 94.5% (SD 10.12; 95% CI 74.70, 100.00). Selective HBP was noted in 44.7% (95% CI 12.5-76.9), while Non-selective-HBP was noted at rate of 42.2% (95% CI 10.2-74.2). The mean follow-up duration was 21.71 months (SD 3.77; 95% CI 14.32-29.11). All-cause mortality had a pooled proportion of 0.107 (SD 0.110, 95% CI -0.109-0.323); hospitalization proportion was 0.078 (SD 0.072; 95% CI -0.063-0.219). We noted a significant improvement in left ventricular ejection fraction (LVEF) (Baseline [BL] 41.84%, Follow-up [FU] 53.63%, Standardized mean difference [SMD] 0.646, p 0.028), NYHA class (BL 2.77, FU 1.55, SMD -2.542, p &lt;0.001) and LV end diastolic volume (SMD -0.495, 95% CI -0.721, -0.269, p &lt;0.001). We found a significant rise of threshold potential (BL 1.12 V, FU 1.49 V, SMD 0.393, p &lt;0.001 and an increase between baseline and follow up QRS duration (BL 102.21 ms, FU 106.90 ms, SMD 0.646, p 0.028). Conclusion: HBP and AVNA are feasible, safe, effective and has high success rate for management of refractory AF. Further studies are needed to evaluate its role in comparison to left bundle branch area pacing and cardiac resynchronization therapy to evaluate comparative efficacy in refractory AF.

Abstract 13251: Left Bundle Branchpacing Post-Atrioventricular Junction Ablation for Atrial Fibrillation: A Propensity Score Matching Analysis

Introduction: Although left bundle branch pacing (LBBP) has emerged as a novel pacing modality which can allow for safe atrioventricular junction (AVJ) ablation and lower pacing threshold compared to His bundle pacing (HBP), its long-term safety and efficacy in patients with atrial fibrillation (AF) is still unknown. Hypothesis: This study aimed to examine the long-term clinical feasibility, safety, and efficacy of LBBP in AF patients post-AVJ ablation and provide a balanced comparison of LBBP versus HBP. Methods: This study prospectively enrolled patients with AF and heart failure (HF) who underwent AVJ ablation and LBBP from July 2017 to December 2019. The control group patients were selected, by propensity score (PS) matching with a 1:1 ratio, among those HBP implantations performed in the years 2012-2019. Results: A total of 99 patients were enrolled in this study, with successful permanent LBBP post-AVJ ablation in 100% of patients (primary LBBP: 76; secondary LBBP: 23). Significantly improvements were observed in LVEF, tricuspid regurgitation, and mitral regurgitation at 1-year follow-up (p&lt;0.05). The proportion of patients whose acute threshold &lt;1 V@0.5ms was 97.9% and only one patient had an increase in threshold ≥1 V@0.5ms at 1-year follow-up. Further, patients with LBBP as an active-group was compared to patients with HBP (control-group) through PS matching with 170 successfully matched (PS-HBP, N=85; PS-LBBP, N=85). In the control-group, the success rate of permanent HBP was 81.9% (176/215), which was lower than that with LBBP (p&lt;0.001). No significant differences in clinical outcomes were observed between groups (p&gt;0.05), while lower thresholds, greater sensed R-wave amplitudes, and less complication were observed in PS-LBBP group (p&lt;0.05). Conclusions: LBBP is feasible, safe, and effective in AF and HF patients post-AVJ ablation, which has comparable clinical benefit, higher success rate, better pacing parameters, and less complication than HBP.

Permanent His-bundle pacing using distal His-bundle electrogram-guided approach in patients with atrioventricular block.

Permanent His-bundle pacing (HBP) is effective and safe; however, the success rate of HBP is low, especially in patients with infranodal block. This study aimed to assess the efficacy and feasibility of HBP implantation using an electrophysiological guided approach targeting a distal His-bundle electrogram (HBE) in patients with atrioventricular block (AVB). Thirty-four consecutive patients with AVB (infranodal block in 28 patients) who underwent HBP were enrolled. During implantation, we attempted to target the distal part of the HBE (distal HBE) beyond the block site based on unipolar mapping. The His-capture threshold was evaluated for 1 year after implantation. HBP was achieved in 26 patients and in 21 patients (75%) with infranodal block. Detection of distal HBE was significantly higher in the successful HBP group than in the HBP failure group (65.4%vs. 0%, p=.001). Among 15 patients with intra-Hisian block, 14 patients (93%) successfully achieved HBP with distal HBE detection. During the 1-year follow-up period, an increase in His-capture threshold by ≥1.0 V at 1.0ms occurred in five (19.2%) of 26 patients. The increased His-capture threshold group exhibited significantly less detection of distal HBE (20%vs. 76.2%; odds ratio 0.078, 95% confidence interval 0.07-0.87, p=.038) and a higher His-capture threshold at implantation (2.0 ± 1.1 V vs. 1.1 ± 0.9 V; odds ratio 1.702, 95% confidence interval 1.025-2.825, p=0.04) than the non-increased His-capture threshold group. HBP implantation guided by distal HBE approach may be feasible with subsequent stable pacing in patients with intra-Hisian and atrioventricular nodal block.

Novel approach to diagnosis of His bundle capture using individualized left ventricular lateral wall activation time as reference.

During nonselective His bundle (HB) pacing, it is clinically important to confirm His bundle capture versus right ventricular septal (RVS) capture. The present study aimed to validate the hypothesis that during HB capture, left ventricular lateral wall activation time, approximated by the V6 R-wave peak time (V6 RWPT), will not be longer than the corresponding activation time during native conduction. Consecutive patients with permanent HB pacing were recruited; cases with abnormal His-ventricle interval or left bundle branch block were excluded. Two corresponding intervals were compared: stimulus-V6 RWPT and native HB potential-V6 RWPT. The difference between these two intervals (delta V6 RWPT), which was diagnostic of lack of HB capture, was identified using receiver operating characteristic (ROC) curve analysis. A total of 723 electrocardiograms (ECGs) (219 with native rhythm, 172 with selective HB, 215 with nonselective HB, and 117 with RVS capture) were obtained from 219 patients. The native HB-V6 RWPT, nonselective-, and selective-HB paced V6 RWPT were nearly equal, while RVS V6 RWPT was 32.0 (±9.5) ms longer. The ROC curve analysis indicated delta V6 RWPT > 12 ms as diagnostic of lack of HB capture (specificity of 99.1% and sensitivity of 100%). A blinded observer correctly diagnosed 96.7% (321/332) of ECGs using this criterion. We validated a novel criterion for HB capture that is based on the physiological left ventricular activation time as an individualized reference. HB capture can be diagnosed when paced V6 RWPT does not exceed the value obtained during native conduction by more than 12 ms, while longer paced V6 RWPT indicates RVS capture.

The Story of Managed Ventricular Pacing

A significant milestone in cardiac pacing occurred approximately two decades ago, when the primary operating mode was reimagined to more closely mimic normal top-down cardiac activation. When introduced, Managed Ventricular Pacing (MVP™; Medtronic, Minneapolis, MN, USA) was an unprecedented dual-chamber mode as it preferentially paced the right atrium in the AAI/R mode and simultaneously protected against transient heart block, albeit only in the instance of dropped ventricular beats. At the time, dual-chamber DDD/R with atrial-based timing and programmable atrioventricular delay was state of the art. MVP™ “unlocked” conventional dual-chamber pacing by not consistently requiring a 1:1 atrioventricular relationship during its primary operating mode (ie, AAI/R+). Ultimately, MVP™ emerged as a primitive means to promote His–Purkinje activation, and it is not a coincidence that its roots can be traced back to first-in-man permanent His-bundle pacing.

B-PO02-046 DOUBLE SHEATH-DOUBLE LEAD TECHNIQUE TO OVERCOME DIFFICULT CASES OF HIS BUNDLE LEAD IMPLANTATION

B-PO02-046 DOUBLE SHEATH-DOUBLE LEAD TECHNIQUE TO OVERCOME DIFFICULT CASES OF HIS BUNDLE LEAD IMPLANTATION

A novel and practical technique to facilitate lead insertion at the His bundle region.

His bundle (HB) pacing techniques are challenging and time-consuming. This is primarily due to the limitations in locating the relatively small area of the HB body for pacing. Permanent HB pacing was performed in 133 consecutive patients with symptomatic bradycardia. A right atrial septo-gram (RAS) was performed in all patients to locate the HB. Briefly, 8-10cc of contrast was injected through the Medtronic C315HIS delivery sheath while fluoroscopy cine runs were obtained in the RAO 15-20° projection. The images obtained provided the visualization of an approximately 90° angle composed by the medial aspect of the tricuspid valve annulus (TVA) anteriorly and the superior aspect of the interatrial septum superiorly. The apex of this angle coincides with the tip of the triangle of Koch (TK), where the HB body is usually located. A Medtronic SelectSecure™ MRI SureScan™ Model 3830 lead was then advanced and directed towards this area. The HB was mapped using pace mapping and unipolar recordings from the lead tip. Localization of the apex of the TK/HB body with the RAS was successful in all patients. The overall acute success of inserting the lead at the HB was 95%. This study demonstrated that our method of utilizing a RAS to facilitate the localization the HB body proved to be safe and efficient in achieving permanent HB pacing with a success rate higher than previously reported.