His Bundle Pacing Lead Research Articles

Extraction of old His bundle pacing leads and coronary sinus leads - an analysis of 3897 lead extraction procedures including 27 His and 253 coronary sinus lead removals

Abstract Background The lumen-less the Medtronic 3830 lead is most popular for His bundle pacing (HBP) and experience with such lead extraction are very limited especially for leads older than 4 years. Methods Analysis of 3898 transvenous lead extraction (TLE) procedures (including 27 HBP and 253 LVP lead extraction) was performed. Results The HBP was used usually in the CRT-D system (72.4%) and EF and NYHA class were better than patients with LVP extracted leads. Age of extracted HBP or LVP lead did not differ significantly (54.5 vs 50.2 months). Extraction of "old" HBP leads extraction was longer than in case of "young HBP leads (8,6 and 3.8 min). Mechanical dilatation was necessary in 63 and 100% extracted HBP leads. Unexpected procedure difficulties appeared (14,3%) and utility of second line / advanced tools had been utilised (28,6%) only when "old" HBP lead were extracted. Difficulties in extracting HBP leads were comparable to those encountered in the extraction of LVP leads of similar age. There was no extracted 3830 extracted lead break and no major complication, necessity of rescue cardiac surgery and procedure related death when HBP and LVP leads were extracted. The length of the FU period for those still alive patients was shorter for patients with removed leads for HBP as this technique was introduced significantly later than LVP. However, the 1-month mortality rate of patients with LVP lead removed is higher than in the HBP and control groups. Conclusions 1. HBP most frequently is utilised in the CRT-D system for resynchronisation of failing heart (72.4%) 2. Extraction of HBP leads is performed most frequently due to non-infective indications (59,3%) and most often because of lead dysfunction (33,3%). 3. Extraction of "old" (>40 mth) HBP leads is twice longer than younger ones (3.8 and 8,6 min) and mechanical dilatation is necessary frequently. 4. Extraction of "old" (>40 mth) HBP leads is more difficult than younger ones due to appearance unexpected procedure difficulties (14,3%) and necessity utility of second line / advanced tools (28,6%) but it does not entail the risk of major complications and procedure related death. 5. Difficulties in extracting HBP leads comparable to those encountered in the extraction of LVP leads of similar age. 6. Survival after HBP and LVP lead extraction was comparable, but shorter than after removal of other leads.

Extraction of His Bundle Pacing Lead: More Difficult than Coronary Sinus Lead Extraction: An Analysis of 3897 Lead Extraction Procedures Including 27 His and 253 Coronary Sinus Lead Removals.

Experience with the transvenous extraction of leads used for His bundle pacing (HBP) is limited. Analysis of 3897 extractions including 27 HBP and 253 LVP (left ventricular pacing) leads. The main reason for HBP lead extraction was lead failure (59.26%). The age of HBP and LVP leads (54.52 vs. 50.20 months) was comparable, whereas procedure difficulties were related to the LVP lead dwell time. The extraction of HBP leads > 40 months old was longer than the removal of younger leads (8.57 vs. 3.87 min), procedure difficulties occurred in 14.29%, and advanced tools were required in 28.57%. There were no major complications. The extraction time of dysfunctional or infected leads was similar in the HBP and LVP groups (log-rank p = 0.868) but shorter when compared to groups with other leads. Survival after the procedure did not differ between HBP and LVP groups but was shorter than in the remaining patients. 1. HBP is used in CRT-D systems for resynchronisation of the failing heart in 33.33%. 2. Extraction of HBP leads is most frequently performed for non-infectious indications (59.26%) and most often because of lead dysfunction (33.33%). 3. The extraction of "old" (>40 months) HBP leads is longer (8.57 vs. 3.87 min) and more difficult than the removal of "young" leads due to unexpected procedure difficulties (14.29%) and the use of second line/advanced tools (28.57%), but it does not entail the risk of major complications and procedure-related death and is comparable to those encountered in the extraction of LVP leads of a similar age. 4. Survival after lead extraction was comparable between HBP and LVP groups but shorter compared to patients who underwent the removal of other leads.

Conduction System Pacing Upgrade in Chronic Heart Failure with Severe Left Ventricular Dysfunction and Chronic Atrial Fibrillation.

Cardiac resynchronization therapy (CRT) is a standard treatment for patients with severe congestive heart failure. However, one-third of patients receiving CRT are non-responders. Conduction system pacing (CSP), including His-bundle pacing (HBP) and left bundle branch area pacing (LBBAP), has become an alternative to CRT therapy. Furthermore, CRT therapy with CSP has shown to be more effective than CRT alone. When an implantable cardiac defibrillator or CRT-defibrillator is implanted with CSP, the problem of which port the HBP lead and LBBAP lead should be connected to arises. We report 2 cases of upgrading to CRT with CSP by utilizing the atrial ports for HBP and LBBAP leads. The procedure is a simple, reasonable, and effective therapy for end-stage heart failure.

PO-03-015 HIS BUNDLE PACING: OUTCOME AFTER 10-YEARS FOLLOW-UP

His bundle pacing (HBP) ensures a physiologic ventricular activation and can prevent pacing-induced cardiomyopathy. Published experiences confirm good clinical results on short-term follow-up. Data on long-term follow-up are still lacking. to analyze technical and clinical outcomes of HBP in an unselected population after a very long-term follow-up. Retrospective analysis of 370 patients (mean age 75±8 years; 221 males) with standard indication for pacing implanted with HBP from 2003 to 2012. In 52% selective-HBP was obtained while 48% were non selective-HBP. In all cases the HBP was performed by lumenless fixed screw lead and deflectable sheath C304. The indications for pacing were AV block 51%, sinus node disease 22%, atrial fibrillation and slow ventricular rate 25%, heart failure 2%. Ischemic cardiopathy was found in 84 pts (29%); hypertension in 317 pts (86%) and diabetes in 108 pts (29%). Pre-implant QRS was 119±30 ms and basal mean EF 57±11%. The His lead was inserted in ventricular port of CRT-P device in 162 (44%) pts, in atrial port of a DR device in 183 (49%) pts, and in ventricular channel of a SR device in 25 (7%) pts. A back-up lead was implanted in right apex or septum in 203 (55%) patients. All patients were checked once a year. 124 (34%) pts overstepped 10 years follow-up (mean 12.3 ±1.8 years), they were analyzed on technical and clinical performance. At the end of follow-up, the mean EF was 61±8% (P=NS) and the mean paced QRS 123 ± 27 (P=NS). 10 (8%) patients had heart failure hospitalizations. 26 (21%) died after 12.1 ±1.7 years. From a technical point of view, 99 (80%) pts showed good performance of the HBP lead at the last follow-up while 25 (20%) pts experienced lead-related problems: 20 (16%) had HBP lead issues (2 cases of severe HBP malfunction required hospitalization due to syncope) and 5 (4%) had malfunction of the back-up lead. The mean devices longevity was 6.6 ±2.6 years and each patient had 1.5 ±0.8 replacements. It was required to add a back-up catheter in 3.6% of patients. The remaining 205 patients completed a mean follow-up of 6.3±2.7 years while 41(11%) patients were lost at follow-up (died within the first month post-implant or checked in other centres). HBP is safe and feasible in the clinical practice. The system maintains a good performance during a long-term follow-up and ensures a physiologic ventricular contraction thus allowing good clinical outcome. The EF and QRS duration remain in normal values.

His-bundle pacing and atrioventricular nodal ablation for noncontrolled atrial arrhythmia: A technical challenge with major clinical benefits

His-bundle pacing (HBP) is an appealing alternative to right ventricular pacing in patients referred for permanent ventricular pacing and atrioventricular nodal ablation (AVNA) because it preserves physiological ventricular activation. Only limited data regarding HBP combined with AVNA are available in the literature. The purpose of this study was to provide further evidence on the feasibility and efficacy of this therapeutic approach in patients with uncontrolled atrial arrhythmia. We prospectively included all patients who had undergone AVNA after HBP in 3 different hospitals between 2017 and2022. AVNA following HBP lead implantation was performed in 75 patients. Complete atrioventricular (AV) block was obtained in 58 patients (77%), and significant modulation of AV nodal conduction (heart rate <60 bpm) was obtained in 12 patients (16%). AVNA failure was observed in 5 patients (7%). Recording of an atrial signal by the HBP lead was more frequently observed in patients with AVNA modulation/failure than in patients with complete AV block (11/17 vs 5/58; P <.001). No lead dislodgment occurred during the AVNA procedures. Acute His-bundle (HB) capture threshold increase >1 V occurred in 11 patients (15%), with return to baseline value on day 1 in 9 patients. New York Heart Association functional class and left ventricular ejection fraction significantly improved from baseline to last follow-up (3.0 ± 0.7 vs 1.6 ± 0.5; P <.001; and 47% ± 14% vs 60% ± 9%; P <.0001, respectively). AVNA combined with HBP for noncontrolled atrial arrhythmia was feasible and clinically efficient. Implanting the HB lead on the ventricular aspect of the tricuspid annulus avoiding atrial signal recording can facilitate AVNA.

Abstract 13583: Conduction System Pacing Experience: His Bundle vs. Left Bundle Branch Area Pacing at Columbia University

Introduction: Conduction system pacing (CSP) with His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) are utilized as alternatives to RV endocardial and biventricular pacing. Which patients gain the most benefit from CSP remains an area of active investigation. Objective: To report on the early experience with HBP and LBBAP conduction system pacing at an academic medical center. Methods: All patients with a Medtronic 3830 SelectSecure lead implanted from 3/2016 to 5/2022 at Columbia University were selected for chart review. Patients were excluded if follow up interrogation or clinical data were unavailable for review. Results: A total of 36 patients were included and 3 were excluded for lack of follow up. 25 patients had HBP and 11 patients had LBBAP (Table 1). Average time from implant to most recent interrogation for HBP was 530.8 ± 506.2 days, range 22 - 1589, compared to 113.6 ± 149.6 days, range 10 - 397, for LBBAP. The implant threshold was significantly higher in HBP compared to LBBAP (1.58 ± 1.06 V vs. 0.57 ± 0.19 V, p=0.004) (Table 1). There were increased threshold in both groups at follow up compared to initial implant HBP (1.81 ± 1.19 V vs 1.58 ± 1.06, p=0.17) and LLBAP (&lt; 30 days of follow up [n=4], 0.84 ± 0.66 V vs 0.58 ± 0.22 V,p=0.46; &gt;30 days of follow up [n = 7], 1.34 ± 1.40 vs 0.57 ± 0.19, p=0.18) although it was not significant. Complication rates were low, one HBP lead was deactivated due to high threshold, two LBBAP patients required lead revision, one for dislodgement and one for pocket infection. Conclusions: CSP is a feasible and safe procedure. Higher thresholds were observed in the HBP group at implant compared to the LBBAP group. There was a trend of an increased threshold over time in both groups. Ongoing monitoring of the LBBAP is crucial for long term feasibility.

Abstract 9954: Single Operator Experience, Learning Curve, and Outcomes With Conduction System Pacing

Introduction: Conduction system pacing (CSP) is an increasingly used physiologic pacing modality by either His-bundle pacing (HBP) or left-bundle area pacing (LBAP). However, operators new to this technique may hesitate to implement CSP. We describe a single operator's experience (learning curve, clinical outcomes) with CSP from 07/2016-05/2022. Methods: Retrospective analysis of all 3830 Medtronic SelectSecure leads implanted by one operator at an academic institution. Patient characteristics, procedure times, ECG findings, pacing parameters, and clinical outcomes were analyzed. Results: A total of 140 CSP cases (Medtronic 3830 lead) were attempted over 70 months (78 HBP, 62 LBAP). Implant frequency (year → # of cases): 2016 → 3; 2017 → 5; 2018 → 24; 2019 → 25; 2020 → 36; 2021 → 35; 2022 → 12. The last HBP lead was implanted in March 2021; the 1st LBAP lead was implanted in December 2019. There were 23 unsuccessful attempts to achieve CSP at initial implantation (18 in the 1st 34%, mainly HBP cases; 5 in the last 92 cases) and 5 revisions (all HBP, see figure ). Procedure times shortened after the 1st 25 procedures for both HBP (158 to 132 mins, P=0.028) and LBAP (174 to 133 mins, P=0.002). Mean follow-up: HBP=558.2 days and LBAP=109 days. Ten patients (4 HBP, 6 LBAP) were lost to follow up. LBAP leads showed significantly better capture thresholds compared to HBP at implant and follow-up, although QRS narrowing, LV activation times, and improvement in LV function were not significantly different (see table). Conclusion: LBAP is easier to learn and has fewer failure rates as compared to HBP. Procedure times improve with experience within 25 cases. Majority of failed attempts were in the first third of cases, and all but one were in the HBP group. Operators new to CSP should forego HBP and employ LBAP. LBAP provides similar reductions in QRS duration, LV activation times, and LVEF improvement as compared to HBP, but with lower failure/revision rates and superior long-term pacing thresholds.

Short term outcome of distal (ventricular) His bundle pacing and atrioventricular node ablation in patients with symptomatic atrial fibrillation - Refining the concept

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Many patients with atrial fibrillation (AF) do not benefit from rhythm control due to failed catheter ablation, advanced left atrial disease and comorbidities. "Pace and AV node (AVN) ablation" strategy is often adopted for rate control but with a substantial risk of pacing-induced cardiomyopathy. His bundle pacing (HBP) enables physiological biventricular activation through the His Purkinje conduction system. However, the proximity of the HBP lead to the site of AV node ablation may potentially compromise lead integrity in patients who undergo conventional HBP and AVN ablation. Therefore, we have modified HBP by placing the HBP lead distally at the ventricular side of the His bundle (D-HBP) before AVN ablation in patients with symptomatic AF. All patients had a backup RV lead. Method Patients who had D-HBP as part of a "Pace and AVN ablation" strategy were retrospectively analysed. Implant and device clinic follow-up data were collected and analysed. Result Twenty-one patients who had "pace and AVN ablation strategy" with D-HBP between 26th February 2020 and 3rd November 2021 were included. They had a mean age of 75 ± 1.4 years (mean ± SEM), NYHA class of 2.1 ± 0.2, QRS duration of 106 ± 5.3ms and 50% had at least moderately impaired LV systolic function. Seventeen patients (81%) had narrow QRS duration. D-HBP was successful in twenty of twenty-one patients (95%). At D-HBP implant, the mean acute threshold of the HBP lead was 0.96 ± 0.12V at 0.5 ± 0.05ms and the mean HBP lead impedance was 548.1 ± 29.5Ω. Selective HBP pacing was observed in thirteen of twenty patients. The mean QRS duration of HBP paced beats was 104.5 ± 4.7ms. Failure to capture the His bundle was observed in one patient. AVN ablation was performed on the same day after D-HBP in eleven patients and as a subsequent procedure in nine patients. The mean duration of procedure and fluoroscopy for D-HBP were 77.4 ± 4.6 minutes and 11.9 ± 1.4 minutes respectively. There were no acute procedural complications with no lead damage, displacement or lead perforation observed. The median follow-up period was 207 days. The mean D-HBP lead threshold following AVN ablation was 1.1 ± 0.2 V at 0.6 ± 0.07 ms and the mean lead impedance was 433.8 ± 20.7Ω, which were similar to before AVN ablation. One patient was reprogrammed with RV pacing only for elevated HBP lead threshold after AVN ablation to 4.2 V at 1ms. The mean D-HBP percentage was 92.3 ± 6.6% and the mean estimated battery longevity of the pacemaker was 7.9 ± 0.6 years at the last follow up. There was improvement in heart failure symptoms in eight patients from previously symptomatic to NYHA class I following D-HBP and AVN ablation. Conclusion D-HBP appear to be safe with potentially more favourable lead parameters than conventional proximal HBP in patients with symptomatic AF offered "Pace and AVN ablation" strategy.

Abstract 13774: Comparison of His Bundle Pacing and Bi-Ventricular Pacing in Heart Failure Patients With Atrial Fibrillation Who Need Atrial-Ventricular Node Ablation: The ALTERNATIVE Study

Introduction: Cardiac resynchronization therapy typically is attempted with biventricular pacing (BVP). As an alternative to BVP, his bundle pacing (HBP) can maintain electrical and mechanical synchrony in patients with atrial fibrillation (AF) and atrioventricular node ablation (AVNA). However, there is still a lack of prospective randomized studies to compare BVP and HBP. Hypothesis: For patients with heart failure (HF) and AF who need AVNA, HBP is not inferior to traditional BVP. Methods: ALTERNATIVE is a prospective multicenter randomized single blind crossover study. Fifty consecutive AF patients who received BVP or HBP in conjunction with AVNA between March 2016 and February 2019 were enrolled in 6 centers. Patients were implanted with a right apical pacing lead, left ventricular lead, and HBP lead. After successful implant, patients were randomized in single patient-blinded fashion to either HBP or BVP. After 9 months, patients were crossed over to the other pacing modality and followed for another 9 months. Pacing parameters, echocardiographic measurements were obtained at baseline and at each follow-up. Results: Fifty patients were enrolled from 6 centers in this study. 25 received BVP and 25 HBP at first stage. Thirty-eight patients completed the crossover analysis at 18 months. LVEF were significantly improved for both pacing modes compared with baseline (30.93±7.27% vs. 51.29±10.79%, p&lt;0.001 in HBP; 33.43±9.40% vs. 51.94±10.97%, p&lt;0.001 in BVP). HBP was superior to BVP in terms of post-implant QRS duration (103.33±12.00 ms vs. 132.42±15.25 ms). Moreover, HBP can lead to greater improvement in cardiac function than BVP (p&lt;0.001 in LVEDd; p&lt;0.001 in LVEF). Conclusions: HBP can be used as a favorable alternative to BVP in patients with HF and AF after AVNA whose QRS complex is less than 120 ms. Further long-term and large studies are warranted to compare the outcomes between HBP and BVP.

B-PO01-040 LEAD STABILITY IN HIS BUNDLE PACING—INCIDENCE, PREDICTORS, AND TIMING OF INCREASED PACING THRESHOLDS

His bundle pacing (HBP) is the most physiologic form of pacing and is associated with multiple benefits, but with concerns regarding lead performance and thresholds over time. To describe HBP lead thresholds at baseline and follow-up. Patients implanted with HBP between 2016-2020 were prospectively studied at a single center. Pacing thresholds at baseline and follow-up were analyzed in V-ms (mWebers) to account for changes in pulse-width over time. HBP threshold of ≥ 2 V-ms was considered at high at implant, and any rise ≥ 1.5 V-ms was considered substantial. Among 216 patients with assessed for HBP, 140 received HBP leads. Baseline characteristics included median age 75 years, 63% male, 59% with cardiomyopathy, 41% history of coronary artery disease, 46% with atrial fibrillation, median LVEF 46.4% (30.2-60%), and 38% receiving cardiac resynchronization therapy (CRT) devices. Median QRS width was 130 ms (105-159 ms): 44% narrow, 21% LBBB, 24% RBBB, 10% IVCD. High threshold at baseline was noted in 44 patients (31%). Threshold rise in output voltage was significant across multiple time points, and substantial rise was noted at 2 years (FIGURE). A total 18 (24.3%) demonstrated rise of 1 V-ms at any point in follow-up and 12 (8.6%) demonstrated substantial rise of 1.5 V-ms. Of these, 8 (5.7%) required lead revision. History of atrial fibrillation was predictive of late rise in thresholds. Baseline thresholds were not predictive of substantial late rise. Substantial threshold rise may occur late after HBP and is not predicted by baseline implant thresholds.

B-PO03-056 CULPRIT, BYSTANDER, OR A HOLE OTHER MATTER: ENDOCARDIAL LV PACEMAKER LEAD EXTRACTION FOR SEVERE MITRAL REGURGITATION

LV endocardial lead placement for CRT can be performed, usually when conventional means of CRT have been exhausted. LV endocardial lead placement may have unintended consequences on the mitral valve leading to incomplete coaptation and mitral regurgitation. The indications for extraction of an LV endocardial lead for mitral valve disease and potential long-term consequences are less clear. To understand potential consequences of LV lead placement and extraction. N/A We present a 78-year-old female with a dual chamber pacemaker for intermittent complete heart block who developed progressive decline in LVEF in the setting of high RV pacing burden. Placement of a coronary sinus lead was unsuccessful following two attempts and epicardial lead placement was deferred due to patient preference. An LV endocardial lead was placed via atrial trans-septal access. There was mild mitral regurgitation at the time of implant. Five years later she developed clinical heart failure with severe mitral regurgitation and suspected P3 scallop impingement. The LV endocardial lead was extracted using a laser sheath through the interatrial septum. A HIS bundle pacing lead was placed. The intraoperative TEE did not demonstrate improvement in mitral regurgitation. She had subsequent heart failure admissions and repeat TEE was performed demonstrating moderate to severe mitral regurgitation with incomplete A1/P1 coaptation. She was not felt to be a candidate for percutaneous repair of her valve. She was also found to have a persistent 1.1cm atrial septal defect with bidirectional shunt following device extraction. RHC demonstrated a Qp/Qs of 2.36. She is now referred for atrial septal defect closure. This case highlights the uncertainty in identifying LV endocardial leads as the cause of clinically significant mitral regurgitation. Our patient's mitral regurgitation did not recover appreciably following lead extraction suggesting that functional valve disease played a more significant role. The unclear benefit of lead extraction should be carefully weighed against its risk which includes worsening mitral regurgitation and residual atrial septal defect.

Physiological Pacing: A New Road to Future

Anatomy and physiology are the basis of human body functioning and as we have progressed in management of various diseases, we have understood that physiological intervention is always better than an anatomical one. For more than 50 years, a standard approach to permanent cardiac pacing has been an anatomical placement of transvenous pacing lead at the right ventricular apex with a proven benefit of restoring the rhythm. However, the resultant ventricular dyssynchrony on the long-term follow-up in patients requiring more than 40% ventricular pacing led to untoward side effects in the form of heart failure and arrhythmias. To counter such adverse side effects, a need for physiological cardiac pacing wherein the electrical impulse be transmitted directly through the normal conduction system was sought. His bundle pacing (HBP) with an intriguing alternative of left bundle branch pacing (LBBP) is aimed at restoring such physiological activation of ventricles. HBP is safe, efficacious, and feasible; however, localization and placement of a pacing lead at the His bundle is challenging with existing transvenous systems due to its small anatomic size, surrounding fibrous tissue, long-learning curve, and the concern remains about lead dislodgement and progressive electrical block distal to the HBP lead. In this article, we aim to take the reader through the challenging journey of HBP with focus upon the hardware and technique, selective versus nonselective HBP, indications and potential disadvantages, and finally the future prospects.

Comparison of electrical characteristics between atrial and ventricular side His-bundle pacing in bradycardia patients

Abstract Background His-bundle pacing (HBP) is recognized as the most physiological way of pacing but with less study focused on electrical characteristics in different site. Purpose We aimed to evaluate the differences of pacing and echocardiographic parameters between atrial and ventricular side His-bundle pacing. Methods Patients who successfully underwent HBP implantation from September 2018 to August 2019 were retrospectively analyzed. All patients were assigned to atrial-side HBP (aHBP) group or ventricular-side HBP (vHBP) group according to the location of the His-bundle pacing lead, which was confirmed by two methods including postoperative echocardiography and visualization of tricuspid valve annulus (TVA). The pacing and echocardiographic parameters were compared between two groups during the procedure and at 3-month follow-up. Results A total of 71 bradycardia patients who successfully underwent HBP implantation and confirmed lead position were included. Among them, twenty-seven were assigned to aHBP group and the other 44 were assigned to vHBP group with no significant differences in baseline clinical characteristics between two groups. During the procedure, the proportion of selective HBP was significantly higher (77.8% vs. 11.4%; P&amp;lt;0.01) and the intra-procedural HV intervals was significantly longer (50.85±6.53 ms vs. 42.95±6.02 ms, P&amp;lt;0.01) in aHBP group than in vHBP group. The capture threshold in vHBP group was significantly lower than in aHBP group at implantation (0.92±0.22 V/1.0ms vs. 1.05±0.26 V/1.0ms, P=0.03) and remain significantly difference after 3-month follow-up (0.98±0.23 V/1.0ms vs. 1.15±0.44 V/1.0ms, P=0.03). The R-wave amplitude was significantly higher in vHBP group than in aHBP group at implantation (5.82±2.52 mV vs. 3.74±1.81 mV, P&amp;lt;0.01), and these differences still persisted during follow-up (5.88±2.51 mV vs. 3.67±1.61 mV, P&amp;lt;0.01). During 3-month follow-up, an increase in the capture threshold &amp;gt;1 V/1.0ms was seen in 2 cases in aHBP group while all patients remained stable in vHBP group. One patient developed a pocket hematoma in aHBP group compared to none in vHBP group. None of deterioration of tricuspid regurgitation and other procedure-related complications were observed during 3-month follow-up. Conclusions Ventricular side His-bundle pacing can achieve favourable pacing parameters including a lower pacing threshold and a higher R-wave amplitude than atrial side His-bundle pacing, which may be an ideal pacing strategy for patients in need of ventricular pacing. Funding Acknowledgement Type of funding source: None

Extraction of the permanent His bundle pacing lead: Safety outcomes and feasibility of reimplantation

Permanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing. However, concerns remain about the feasibility and safety of lead extraction from the His bundle region. The aim of our study was to assess the safety and feasibility of extraction of chronically implanted permanent HBP leads in addition to report on the feasibility of reimplanting in the His bundle region. Patients undergoing extraction of leads from the His bundle location for standard indications were studied. The primary outcomes were removal success rates, need for extraction tools, and feasibility of reimplantation in the His bundle region. Thirty patients (male 23 (27%); mean age 73.3 ± 14 years) with permanent HBP leads of at least 6-month duration were included. The indications for removal of the HBP leads were infection (n=3), lead failure (n = 22), nonfunctional lead (n = 3), and upgrade to implantable cardioverter-defibrillator (n = 2). The mean duration of the implanted leads was 25 ± 18 months (range 6-72 months). Removal of HBP leads was successful in 8 of 8 patients (100%) with ≤12-month duration and 21 of 22 patients (95%) with >12-month duration. Extraction tools were used in 4 patients, while manual traction was successful in the remaining patients. Reimplantation in the His-Purkinje conduction system was successful in 19 of 22 patients (86%). In this largest study of HBP lead extractions, the overall success rate of extraction of chronically implanted HBP leads was high with a low complication rate. The need for mechanical extraction tools was low, and reimplantation in the His-Purkinje conduction system was feasible.

Deep Negative Deflection in Unipolar His-Bundle Electrogram as a Predictor of Excellent His-Bundle Pacing Threshold Postimplant.

Background His-bundle pacing (HBP) is a physiological form of pacing. Although high capture thresholds are common, few predictors of low HBP threshold have been determined. We aimed to identify electrophysiological predictors. Methods Fifty-one patients (53% with atrioventricular block) underwent HBP for bradycardia with an intrinsic QRS duration of <120 ms. Attempts to anchor the HBP lead were guided by unipolar His-bundle electrograms (HB EGMs) recorded with an electrophysiology recording system. Patients were followed-up for >6 months. Results In total, 153 attempts at anchoring the HBP lead were made, of which, 45 achieved acceptable HBP thresholds (≤2.5 V at 1 ms). The amplitude of negative deflection in HB EGM and the selective HBP form at fixation were independently associated with achieving an acceptable threshold. A negative amplitude of ≥0.060 mV in HB EGM was determined as the optimal value for identifying the acceptable threshold. This deep negative HB EGM was recorded with an HBP threshold of 1.4±1.3 V (in 34 attempts), significantly lower than that of positive HB EGM without deep negative deflection (2.8±1.3 V, in 31 trials; or >5 V, in 38 trials). The permanent HBP lead remained with deep negative (≥0.060 mV) or positive HB EGMs in 28 and 14 patients, respectively, and with positive or negative HB injury current in 19 and 23 patients, respectively. During follow-up, increased HBP threshold of >1 V was significantly more prevalent in the positive HB EGM group. The HBP thresholds of deep negative HB EGM and HB injury current, but not of the selective HBP group, were significantly lower than the other subgroups during follow-up. Conclusions Deep negative HB EGM at fixation was associated with an excellent short-term HBP threshold, similar to HB injury current. Analysis of unipolar HB EGM postfixation may enable prediction of permanent HBP threshold.

Direct Visualization of the His Bundle Pacing Lead Placement by 3-Dimensional Electroanatomic Mapping: Technique, Anatomy, and Practical Considerations.

His bundle pacing (HBP) remains technically challenging and is currently guided by electrograms and 2-dimensional fluoroscopy. Our objective was to describe a new technique for HBP directly guided by electroanatomic mapping (EAM). Twenty-eight patients were included. The atrioventricular septum was mapped via EAM, and His bundle (HB) electrograms, selective, and nonselective HB capture sites were tagged. Pacing leads were connected to EAM, navigated to tagged HB target sites and deployed. Intracardiac electrograms and pacing parameters were recorded. Lead location was tagged on the cloud of HB sites, which was divided into 3 arbitrary segments. In 5 patients, atrioventricular nodal ablation was performed with direct visualization of the HBP lead by EAM. Reproducible navigation of the pacing lead to predetermined HBP locations guided by EAM was achieved in all patients. The lead was successfully deployed in 25 patients. HB cloud area was 360 (212) mm2. There was no correlation between HBP threshold and lead location on the His cloud. The intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlated with its EAM position on the His cloud ( P=0.045). Procedure, fluoroscopy, and mapping times were 116.0 (38.8), 8.6 (6.3), and 9.0 (11.4) minutes, respectively. HBP threshold at implant was 1.5 (2.3) V at 1.5 (1.0) ms. Distance between HB lead and ablation sites was 10.0 (1.3) mm in patients undergoing atrioventricular nodal ablation. Direct guidance of HBP by EAM allows for direct visualization of the pacing lead on the HB cloud and reproducible navigation to predetermined HB capture sites. Intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlates with His cloud location. EAM can be applied during standard HBP procedures or combined with atrioventricular nodal ablation.

His bundle pacing in older patient with continuous proximal atrio-ventricular block after myocardial infarction

His bundle pacing (HBP) synchronizes atrio-ventricular and intraventricular delays. We observed the relationship between the level of atrio-ventricular block, ventricles synchrony, diastolic function improvement in a patient with moderate systolic disorders and diastolic dysfunction after myocardial infarction. HBP may be useful to treat conduction disorders and prevent further systolic and diastolic dysfunction. We present the case of a 92-year-old man in a very good general psychophysical status, treated with percutaneous coronary intervention of circumferential branch of left coronary artery angioplasty due to myocardial infarction, regional contractility disorders of left ventricle with ejection fraction (LVEF) 45%, and observed long PR interval with paroxysmal second degree atrioventricular conduction block. A successful implantation of a permanent HBP lead in the postinfarction period was performed. The His bundle capture restored AV synchrony and diminished diastolic disorders. Our case demonstrates that atrioventricular conduction disorders in the course of myocardial infarction may be corrected by HBP.

The influence of His bundle pacing on tricuspid valve functioning using three-dimensional echocardiography

Key Teaching Points • In most patients, the His bundle pacing (HBP) lead is positioned on the atrial side of the His bundle; in others, it is positioned in the tricuspid valve or on the ventricular side of the His bundle. • Echocardiography showed no worsening of tricuspid regurgitation severity in any patient with a permanent HBP, even in those whose leads were located on or under the tricuspid valve. • The HBP lead tip can be positioned in a commissural position in the right ventricle without impinging on leaflet mobility.

Atrioventricular node ablation and His bundle pacing.

Atrioventricular node ablation (AVNA) and right ventricular pacing (RVP) are effective therapies for patients with atrial fibrillation (AF) and rapid ventricular rates. His bundle pacing (HBP) is a physiologic alternative to RVP. The aim of our study is to assess the feasibility and safety of HBP in patients undergoing AVNA and its effect on left ventricular (LV) function. Permanent HBP is the preferred form of ventricular pacing at our institute. Atrioventricular node ablation and HBP were performed in patients with AF and difficulty in rate control. His bundle pacing implant characteristics and thresholds were recorded. Fluoroscopic relationship of AVNA site to HBP lead electrodes was documented. Left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) functional class at baseline and during follow-up were assessed. Forty-two patients underwent HBP and AVNA: age 74 ± 11 years; men 45%; HTN 64%; DM 19%; CAD 36%; permanent AF 40%; cardiomyopathy 55%. His bundle pacing was successful in 40 of 42 patients (95%). Successful AVNA site was at or below the ring electrode in 22 (no acute change in HBP threshold); above the ring electrode in 13 and left side in 2 pts (acute increase in HBP threshold in 7 of 15 pts). Final HBP threshold at implant was 1 ± 0.8 V@1 ms and increased to 1.6 ± 1.2 V@1 ms during a mean follow-up of 19 ± 14 months. Left ventricular ejection fraction increased from 43 ± 13% to 50 ± 11% (P = 0.01). New York Heart Association functional status improved from 2.5 ± 0.5 to 1.9 ± 0.5 (P = 0.04). Atrioventricular node ablation and HBP were successful in 95% of patients. His bundle pacing lead characteristics remained relatively stable. Left ventricular ejection fraction improved significantly during follow-up. His bundle pacing is feasible, safe and effective in pts undergoing AVNA.

Electrophysiological observations of acute His bundle injury during permanent His bundle pacing

BackgroundPermanent His bundle pacing (HBP) is a physiological alternative to right ventricular pacing (RVP). Catheter manipulation during HBP can cause trauma to the His bundle during implantation. We sought to determine acute and long-term incidence of His bundle (HB) injury with HBP. MethodsPatients undergoing permanent HBP at Geisinger Wyoming Valley Medical Center from 2006 to 2014 formed the study group. Patients with pre-existing His-Purkinje disease (HPD) were excluded from the study. Any development of new bundle branch block (BBB) or AV block (B) during acute HBP lead-induced block was recorded. Resolution of AVB and/or BBB was documented. ResultsHBP was attempted in 450 patients. In 358 patients without HPD, 28 (7.8%) developed acute HB injury in the form of complete AVB (4, 1.1%), RBBB (21, 5.9%) or LBBB (3, 0.8%) during HBP lead placement. In all 7 patients with AVB or LBBB, conduction completely recovered. The HB electrogram from the lead displayed injury current in all 7 patients. Lead-induced RBBB resolved in 12 of 21 patients and persisted in 9 (2.5%) patients. Pacing from the HBP lead resulted in correction of acute conduction block in 27 of 28 patients and 8 of 9 patients with chronic RBBB. None of the patients with transient conduction block developed new conduction disease during follow-up of 21±19months. ConclusionsDespite acute trauma to HB in 7.8% of patients undergoing permanent HBP, complete resolution of conduction block occurred in 19 of 28 patients (68%). RBBB persisted in 9 patients (32%) but mostly normalized with HBP.