Left Bundle Branch Research Articles

Bidirectional gated recurrent unit with auto encoders for detecting arrhythmia using ECG data

Heartbeat irregularity or arrhythmia of a patient with serious congestive cardiovascular breakdown is distinguished in this article, and the class not really settled utilizing long haul ECG information. Several existing methods on arrhythmia detection are utilized, which does not accurately classify the Arrhythmia and it takes higher computational time. Morphological filtering and Extended Empirical wavelet transformation preprocess the input data to remove noises and base line. Then these pre-processed data is fed to Ternary Pattern and Discrete Wavelet Transform (TP-DWT) related feature extracting to take relevant feature. Then, the extracted features are given to Bidirectional Gated Recurrent Unit with Auto Encoder (BiGRU-AE) to classify Arrhythmia into Normal, Atrial Fibrillation (AF), First-degree atrioventricular block (1-AVB), Left Bundle Branch (LBBB), Right Bundle Branch Block (RBBB), Premature Atrial Contraction (PAC), Premature Ventricular Contraction (PVC), ST-segment depression (STD) and ST-segment elevation (STE). The proposed BiGRU-AE-AD-ECG is activated in Python and its efficiency is measured under certain metrics, like sensitivity, precision, f-measure, specificity, accuracy, error rate, ROC and computational time. Here, CPSC 2018 dataset is used to validate the efficiency of the BiGRU-AE-AD-ECG method. The performance of BiGRU-AE-AD-ECG method provides 23.40 %, 18.78 % and 28.05 % higher accuracy, 20.41 %, 27.07 % and 18.80 % higher precision, 32.01 %, 27.40 % and 28.95 % higher sensitivity and 28.05 %, 23.41 % and 31.34 % higher specificity analyzed with existing models, like automatic cardiac arrhythmias categorization based on CNN and attention-based RNN network (CNN-RNN-AD-ECG), a multiple lead-branch fusion network under 12-Lead ECG for multiple class arrhythmia categorization (MLBFNet-AD-ECG), analysis of ECG-based arrhythmia identification scheme using machine learning (SVM-AD-ECG)respectively.

Left Bundle Branch Optimized Implantable Cardioverter Defibrillator (LOT-ICD) implantation in a Patient with Myotonic Dystrophy

Left bundle branch (LBB) optimized implantable cardioverter defibrillator (LOT-ICD) is a recently emerged alternative to the standard biventricular pacing - ICD (BiVp-ICD). The IS-1 connector pin of the ICD lead was closed with a protective cap and the LBB pacing (LBBP) lead was inserted into the ICD generator at the ventricular P/S hole. Herein, we presented a myotonic dystrophy patient who underwent LOT-ICD device implantation because of a high degree of atrioventricular block and heart failure with mid-range ejection fraction. A DDD-ICD (DF-1) was implanted in our patient which has been attached to the atrial lead (RA hole), the LBBP lead (ventricular IS-1 hole), and the ICD lead (ventricular DF-1 hole). The IS-1 pin of the ICD lead was closed accordingly. The LOT-ICD should be considered an option to standard BiVp-ICD associated with lower cost, lower procedure time, and no phrenic nerve capture.

Ultra-High-Frequency ECG in Cardiac Pacing and Cardiac Resynchronization Therapy: From Technical Concept to Clinical Application.

Identifying electrical dyssynchrony is crucial for cardiac pacing and cardiac resynchronization therapy (CRT). The ultra-high-frequency electrocardiography (UHF-ECG) technique allows instantaneous dyssynchrony analyses with real-time visualization. This review explores the physiological background of higher frequencies in ventricular conduction and the translational evolution of UHF-ECG in cardiac pacing and CRT. Although high-frequency components were studied half a century ago, their exploration in the dyssynchrony context is rare. UHF-ECG records ECG signals from eight precordial leads over multiple beats in time. After initial conceptual studies, the implementation of an instant visualization of ventricular activation led to clinical implementation with minimal patient burden. UHF-ECG aids patient selection in biventricular CRT and evaluates ventricular activation during various forms of conduction system pacing (CSP). UHF-ECG ventricular electrical dyssynchrony has been associated with clinical outcomes in a large retrospective CRT cohort and has been used to study the electrophysiological differences between CSP methods, including His bundle pacing, left bundle branch (area) pacing, left ventricular septal pacing and conventional biventricular pacing. UHF-ECG can potentially be used to determine a tailored resynchronization approach (CRT through biventricular pacing or CSP) based on the electrical substrate (true LBBB vs. non-specified intraventricular conduction delay with more distal left ventricular conduction disease), for the optimization of CRT and holds promise beyond CRT for the risk stratification of ventricular arrhythmias.

Exploring the effects of His and left bundle branch pacing with stylet-driven lead on tricuspid regurgitation: A short-term follow-up study

The stylet-driven delivery system was replaced with a pre-shaped catheter delivery system for conduction system pacing several years ago, as it offered easier access to the pacing location. However, in several countries, including Indonesia, the availability of catheter systems remains limited. This study aimed to evaluate the occurrence and severity of tricuspid regurgitation when using the stylet-driven lead delivery system in patients undergoing His and Left Bundle Branch (LBB) pacing.

A porcine large animal model of radiofrequency ablation-induced left bundle branch block.

Electrocardiographic (ECG) features of left bundle branch (LBB) block (LBBB) can be observed in up to 20%-30% of patients suffering from heart failure with reduced ejection fraction. However, predicting which LBBB patients will benefit from cardiac resynchronization therapy (CRT) or conduction system pacing remains challenging. This study aimed to establish a translational model of LBBB to enhance our understanding of its pathophysiology and improve therapeutic approaches. Fourteen male pigs underwent radiofrequency catheter ablation of the proximal LBB under fluoroscopy and ECG guidance. Comprehensive clinical assessments (12-lead ECG, bloodsampling, echocardiography, electroanatomical mapping) were conducted before LBBB induction, after 7, and 21days. Three pigs received CRT pacemakers 7days after LBB ablation to assess resynchronization feasibility. Following proximal LBB ablation, ECGs displayed characteristic LBBB features, including QRS widening, slurring in left lateral leads, and QRS axis changes. QRS duration increased from 64.2 ± 4.2ms to 86.6 ± 12.1ms, and R wave peak time in V6 extended from 21.3 ± 3.6ms to 45.7 ± 12.6ms. Echocardiography confirmed cardiac electromechanical dyssynchrony, with septal flash appearance, prolonged septal-to-posterior-wall motion delay, and extended ventricular electromechanical delays. Electroanatomical mapping revealed a left ventricular breakthrough site shift and significantly prolonged left ventricular activation times. RF-induced LBBB persisted for 3weeks. CRT reduced QRS duration to 75.9 ± 8.6ms, demonstrating successful resynchronization. This porcine model accurately replicates the electrical and electromechanical characteristics of LBBB observed in patients. It provides a practical, cost-effective, and reproducible platform to investigate molecular and translational aspects of cardiac electromechanical dyssynchrony in a controlled and clinically relevant setting.

Development of the Cardiac Conduction System.

The electrical impulses that coordinate the sequential, rhythmic contractions of the atria and ventricles are initiated and tightly regulated by the specialized tissues of the cardiac conduction system. In the mature heart, these impulses are generated by the pacemaker cardiomyocytes of the sinoatrial node, propagated through the atria to the atrioventricular node where they are delayed and then rapidly propagated to the atrioventricular bundle, right and left bundle branches, and finally, the peripheral ventricular conduction system. Each of these specialized components arise by complex patterning events during embryonic development. This chapter addresses the origins and transcriptional networks and signaling pathways that drive the development and maintain the function of the cardiac conduction system.

Tall R waves in the right precordial leads as a possible expression of left septal fascicular block

Histological, physiological and pathophysiological studies have shown that the left bundle branch mainly divides into three fascicles, and a septal (middle) fascicle is present in over half of human hearts. Electrocardiographic criteria for the diagnosis of the block of this fascicle have been suggested by some authors: tall R waves in lead V2 and sometimes in V1 in the absence of a right bundle branch block pattern or a well evident jump of R waves from V1 to V2, absence of initial septal q waves and/or possible small q waves in the right precordial leads, normal QRS duration and normal QRS axis. At present, this intraventricular block can only be suspected but not diagnosed with certainty even after clinical/instrumental exclusion of pathological situations associated with tall R waves in leads V1 and V2 (right ventricular hypertrophy, lateral infarction, severe septal hypertrophy) because of the marked variability of normal ECG and the potential presence of confounding diseases.

Cardiac resynchronization therapy in acute heart failure and left bundle-branch block in a real-life registry.

To determine the prevalence, characteristics, timing of implementation and prognosis of patients with left bundle branch block (LBBB) and acute heart failure (AHF) treated with cardiac resynchronization therapy (CRT) in a real-life registry. We analysed the characteristics of patients with AHF and LBBB at the time of inclusion in the EAHFE (Epidemiology Acute Heart Failure Emergency) cohort to determine the indication for CRT, the timing of implementation and its impact on 10-year all-cause mortality. 729 patients with a median age of 82 years and there was a high burden of comorbidities and functional dependence. The median left-ventricle ejection fraction (LVEF) was 40%. Forty-six (6%) patients were treated with CRT at some point during follow-up, with a median time of delay for CRT implementation of 960 (IQR=1,147 days) and at least 108 more untreated patients fulfilled criteria for CRT. Patients receiving CRT were younger, had different comorbidities, less functional dependence (higher Barthel index) and lower LVEF values. The median follow-up was 5.7 years (95% CI: 5.6-5.8) and CRT was not associated with changes in 10-year mortality (adjusted HR 1.33, 95% CI: 0.72-2.48; p-value 0.4). When compared with untreated patients fulfilling criteria for CRT, very similar results were observed (adjusted HR 1.34, 95% CI: 0.67-2.68). CRT implementation was delayed and underused in patients with AHF and LBBB. Under these circumstances, CRT is not associated with a reduction in all-cause mortality in the long term.

Upper turnaround point in a reentry circuit of the idiopathic left posterior fascicular ventricular tachycardia.

The anatomic extent of the reentry circuit in idiopathic left posterior fascicular ventricular tachycardia (LPF-VT) is yet to be fully elucidated. We hypothesized that entrainment mapping could be used to delineate the reentry circuit of an LPF-VT, especially including the upper turnaround point. Twenty-three consecutive LPF-VT patients (mean age, 29±9 years, 18 males) were included. We performed overdrive pacing with entrainment attempts at the left bundle branch (LBB) and the left His bundle (HB) region. Overdrive pacing from the LBB region showed concealed fusion in all 23 patients (post-pacing interval [PPI], 322.1±64.3ms; tachycardia cycle length [TCL], 319.0±61.6ms; PPI-TCL, 3.1±4.6ms) with a long stimulus-to-QRS interval (287.9±58.0ms, approximately 90% of the TCL). Pacing from the same LBB region at a slightly faster pacing rate showed manifest fusion with antidromic conduction to the LBB and minimal in-and-out time to the LBB potential (PPI-TCL, 21.3±13.7ms). Overdrive pacing from the left HB region showed manifest fusion with a long PPI-TCL (53.9±22.5ms). Our pacing study results suggest that the upper turnaround point in a reentry circuit of the LPF-VT may extend to the proximal His-Purkinje conduction system near the LBB region but below the left HB region. The LPF may constitute the retrograde limb of the reentry circuit.

Chagas disease stroke and associated risk factors: A case-control study

Introduction: The intricate relationship between Chagas disease and ischemic stroke remains unclear. Limited evidence exists concerning secondary prophylaxis, etiological diagnosis, and stroke-related determinants. This study aims to discern factors linked to stroke in Chagas disease by contrasting patients with and without a history of ischemic stroke. Methods: Retrospective data from all outpatient Chagas disease patients from two Brazilian hospitals – one Chagas center and one stroke clinic – were examined. Descriptive analyses were conducted to identify stroke-associated factors. Variables were compared between patients with and without ischemic stroke history. Results: Among 678 subjects, 72 had experienced stroke. Univariate associations with stroke included male gender, heart failure, prior or ongoing alcoholism, electrocardiographic features (non-sinus rhythm, left bundle branch, right bundle branch block, left anterosuperior fascicular block, atrial fibrillation), as well as echocardiographic findings indicative of reduced left ventricular ejection fraction and segmental abnormalities. After logistic regression (multivariate analysis), congestive heart failure, right bundle branch block, left anterosuperior divisional block, and atrial fibrillation retained independent associations. Conclusion: In this study, cardiac involvement emerged as the predominant factor correlated with stroke in Chagas disease. While atherosclerosis-related risk factors were prevalent, their influence on ischemic stroke in Chagas disease appeared limited.

The number of screwing attempt and predictors for the success of left bundle branch area pacing : A multicenter experience with standard stylet-driven pacing leads

Abstract Objectives Although Left Bundle Branch Area Pacing (LBBAP) is emerging conduction system pacing modality, it is unclear which parameters are predictive of procedural success and how many screwing attempts are acceptable. This retrospective observational study sought to assess predictors of successful LBBAP, left bundle branch (LBB) capture, and factors associated with the number of screwing attempts. Methods We performed a multicenter retrospective analysis of 120 patients who underwent LBBAP with stylet driven lead. We analyzed factors affecting the number of screwing attempts and procedural success. Procedural, 12-lead ECG, echocardiographic parameters and clinical variables were used in multivariate analyses. Results LBBAP success rate was 95.8% (115/120), and LBB capture success rate was 86.1% (99/115). Few screwing attempts was associated with procedural success (2.1 ± 1.2, 2.7 ± 1.2, and 3.5 ± 1.3 in LBBAP with LBB capture, LBBAP without LBB capture and failed LBBAP group, respectively) (p for trends=0.03). 4 or more screwing attempt was independently associated with higher complication rate compared to fewer screwing attempt (n≤3) (p<0.05). The larger RA size (B = 1.901, 95% confidence interval [CI] 1.07 - 2.73, p <0.001), smaller RV size (B = -0.995, 95% CI -1.88 - -0.31, p = 0.007), and intraventricular conduction delay (IVCD) at pre-implant ECG were independently associated with more screwing attempts. Larger RA size (4th quartile) was associated with larger final sheath size and frequent sheath size change to larger sheath when compared to others. Conclusions More screwing attempts was associated with failed LBBAP procedure and failed LBB capture, and 4 or more screw attempts was associated with higher complication rate. Larger the RA size, smaller the RV size, and IVCD in pre-implant ECG are predictive of more screwing attempt.

Abstract 13371: Left Bundle Branch Area Pacing: Experiences From the First Two Years Implanting in an Academic Training Program

Background: Left bundle branch area pacing (LBBAP) has emerged as a more durable physiologic pacing strategy to His bundle pacing and a promising alternative to cardiac resynchronization therapy. Integration of this procedural technique within an academic training program has not yet been described. Objective: Highlight the procedural learning curve of implanting LBBAP leads within a fellowship program. Methods: Retrospective analysis of consecutive patients who underwent placement of a Medtronic 3830 lead for LBBAP at our institution from 1/2021-12/2022. Results: A total of 180 patients underwent LBBAP lead placement over the study time period. Overall, total procedure time was 133.7±58.2min, lead placement time 30.7±20.0min, fluoroscopy time 22.5±21.2 min, left bundle branch (LBB) capture rate 70% and paced QRS duration 128.6±19.3 ms. When dividing the study period by 6-month intervals, there was a rise in procedural volume (21, 28, 62 and 59 cases, respectively), a trend towards less fluoroscopy use (20.2±12.2, 16.7±9.1, 16.2±12.6 and 16.6±14.4 min), less total radiation (345.2±323.3, 317.2±630.9, 214.9±271.2 and 171.7±253.9 mGy), decreased LBBAP lead placement time (37.8±24.3, 30.7±16.3, 28.2±21.5, 30.6±18.7 min), decreased delivery system exchanges (19%, 11%, 8% and 2%*, *p≤0.01 from first six months) and improved LBB capture rates (50%, 69%, 83%*, 64%, *p≤0.01 from first six months). Both fellowship classes showed significant improvements in LBB capture rates (40% to 94% and 38% to 84%, p≤0.01 for both) and paced-QRS duration (140.0±27.2ms to 120.2±16.5ms and 136.2±21.8ms to 121.7±17.2ms, p≤0.05 for both) after 12 months of experience. Conclusion: Over the first two years of performing LBBAP in an academic training program, there was a rise in procedural volume with trends towards less fluoroscopy use, decreased LBBAP lead placement time with significantly decreased delivery system exchanges and improved LBB capture rates. Significant improvements in LBB capture rates and paced-QRS duration were seen by fellows after 12 months of experience. LBBAP is an increasingly popular pacing technique that can be effectively integrated within a training program, with early introduction important to accommodate the initial learning curve.

Estimulación fisiológica: estado actual y perspectivas futuras

Conduction system pacing is a cardiac pacing modality that seeks to maintain ventricular electromechanical activation synchrony through direct stimulation of the specific conduction system, generally the bundle of His or the left bundle branch. Although technically more complex than conventional right ventricular pacing, the advent of dedicated tools has favored its implementation in clinical practice as a more physiologic alternative to conventional right ventricular pacing and as a rescue strategy when conventional resynchronization therapy through biventricular pacing is not feasible. More recently, the growing scientific evidence that compares it to the latter would place it as a real alternative strategy in patients with heart failure and an indication for resynchronization. This text reviews the fundamentals of the main implant modalities and technique, the available scientific evidence, and future prospects.

An effective mathematical model of cardiac electrical activities for Bundle Branch Blocks

In this paper a mathematical model of cardiac induction system is developed. Sinoatrial node (SA), atrioventricular node (AV) and His Purkinje system (HP) are represented by modified Van der Pol-type oscillators (VDP) connected with time-delay coupling. Atrial and ventricular muscles are modeled using modified Aliev-Panfilov equations (AP), with stimulation current from the related pacemakers, to represent the P, QRS, Ta, and T waves. The main aim of this paper is to model bundle branch blocks (BBBs) for right (RBBB) and left (LBBB) branches. In fact, the right and left ventricles are directly affected by these blocks since the HP bundle is composed of right and left bundle branches that provide electrical signals, respectively, to the right and left ventricles. Four VDP oscillators are utilized, one for each of SA, AV, right HP, and left HP. The depolarization of the right and left ventricular muscles are represented by two systems of AP equations to produce right QRS and left QRS waves. The results of the simulation are compared with real normal and pathological electrocardiograms (ECGs) to show the effectiveness and the accuracy of the proposed model. The simulation proves that the model can reproduce the blocks in the HP bundle branches.

Pacing for atrioventricular block with preserved left ventricular function: On-treatment comparison between his bundle, left bundle branch, and right ventricular pacing

Pacing for atrioventricular block with preserved left ventricular function: On-treatment comparison between his bundle, left bundle branch, and right ventricular pacing

Tailored electrocardiographic-based criteria for different pacing locations within the left bundle branch

BackgroundElectrocardiographic (ECG)-based criteria are used to confirm left bundle branch (LBB) pacing (LBBP), but current cutoff values have never been validated for different pacing locations. ObjectiveThe purpose of this study was to describe diagnostic performance of V6-R wave peak time (RWPT), V6-V1 interpeak interval, and aVL-RWPT for different pacing sites within the LBB and to determine 100% specific values for each criterion at each pacing location. MethodsConsecutive patients with confirmed LBBP were selected. Population was divided into subgroups based on the site of pacing: left bundle trunk pacing (LBTP), left septal fascicular pacing (LSFP), left posterior fascicular pacing (LPFP), and left anterior fascicular pacing (LAFP). ResultsA total of 147 patients with unequivocal LBB capture were analyzed. Left fascicular pacing was more frequently achieved (82.8%) than LBTP (17.2%). Diagnostic performance of V6-RWPT, V6-V1 interpeak interval, and aVL-RWPT for discrimination of LBBP was good in all subgroups. V6-RWPT cutoff values with 100% specificity (SP) for LBBP discrimination were 75 ms in LBTP, 68 ms in LPFP, 81 ms in LAFP, and 79.5 ms in LSFP. V6-V1 interpeak interval cutoff values with 100% SP for LBBP discrimination were 35.5 ms in LBTP, 53.5 ms in LPFP, 41 ms in LAFP, and 46 ms in LSFP. In LAFP, aVL-RWPT cutoff value with 100% SP for LBBP discrimination was 68 ms, but was 74 ms in LBTP, 74.5 ms in LSFP, and 73.5 ms in LPFP. ConclusionsTailored ECG-based criteria might be useful to confirm LBBP at different pacing locations within the LBB.

Feasibility and safety of left bundle branch area pacing in patients with septal hypertrophy.

Left bundle branch area pacing (LBBAP) aims to provide physiological ventricular activation during pacing. Left ventricular septal hypertrophy (LVSH) might be challenging for LBBAP due to the thickness of the interventricular septum and potential presence of septal scar. This study assesses the feasibility, safety, and outcome of LBBAP in patients with LVSH using primarily stylet-driven leads (SDL). Adult patients with LVSH who underwent LBBAP between March 2019 and November 2022 were enrolled. Baseline patient characteristics, procedural data and postprocedural results were collected. The feasibility of LBBAP in LVSH patients was compared to a cohort of LBBAP patients with normal septal wall thickness (NST). SeventeenLVSH and 133 NST patients underwent LBBAP with successful implantation achieved in 15 LVSH patients (88%). Mean implant depth was 17.2 ± 1.9 mm, with 53% proven left bundle branch (LBB) capture. Paced QRS duration (146 ± 14 ms) and V6 R-wave peak time (V6 RWPT; 79 ± 20 ms) were comparable between patients with and without septal hypertrophy, although patients with NST had higher rates of proven LBB capture (71% vs. 53%). In LVSH pacing thresholds (0.6 ± 0.3 V at 0.4 ms) and R-wave amplitude (13.9 ± 5.6 mV) were favorable and remained stable at follow-up. At 12 months, 87% of patients had stable or improved left ventricular ejection fraction. The results of the study indicate that LBBAP in patients with LVSH is safe and feasible and no lead-related complications were observed despite a mean implant depth exceeding 15 mm. LBBAP using SDL results in favorable pacing and electrocardiographic characteristics in LVSH patients, comparable to patients with NST.

Predictors of implantation failure in left bundle branch area pacing using a lumenless lead in patients with bradycardia.

Left bundle branch area pacing (LBBAP) is a novel conduction system pacing technique. In this multicenter study, we aimed to evaluate the procedural success, safety, and preoperative predictors of procedural failure of LBBAP. LBBAP was attempted in 285 patients with pacemaker indications for bradyarrhythmia, which were mainly atrioventricular block (AVB) (68.1%) and sick sinus syndrome (26.7%). Procedural success and electrophysiological and echocardiographic parameters were evaluated. LBBAP was successful in 247 (86.7%) patients. Left bundle branch (LBB) capture was confirmed in 54.7% of the population. The primary reasons for procedural failure were the inability of the pacemaker lead to penetrate deep into the septum (76.3%) and failure to achieve shortening of stimulus to left ventricular (LV) activation time in lead V6 (18.4%). Thickened interventricular septum (odds ratio [OR], 2.48; 95% confidence interval [CI], 1.15-5.35), severe tricuspid regurgitation (OR, 8.84; 95% CI, 1.22-64.06), and intraventricular conduction delay (OR, 8.16; 95% CI, 2.32-28.75) were preoperative predictors of procedural failure. The capture threshold and ventricular amplitude remained stable, and no major complications occurred throughout the 2-year follow-up. In patients with ventricular pacing burden >40%, the LV ejection fraction remained high regardless of LBB capture. Successful LBBAP was affected by abnormal cardiac anatomy and intraventricular conduction. LBBAP is feasible and safe as a primary strategy for patients with AVB, depending on ventricular pacing.

Redefining QRS transition to confirm left bundle branch capture during left bundle branch area pacing.

QRS transition criteria during dynamic manoeuvers are the gold-standard for non-invasive confirmation of left bundle branch (LBB) capture, but they are seen in <50% of LBB area pacing (LBBAP) procedures. We hypothesized that transition from left ventricular septal pacing (LVSP) to LBB pacing (LBBP), when observed during lead penetration into the deep interventricular septum (IVS) with interrupted pacemapping, can suggest LBB capture. QRS transition during lead screwing-in was defined as shortening of paced V6-R wave peak time (RWPT) by ≥10 ms from LVSP to non-selective LBBP (ns-LBBP) obtained during mid to deep septal lead progression at the same target area, between two consecutive pacing manoeuvres. ECG-based criteria were used to compared LVSP and ns-LBBP morphologies obtained by interrupted pacemapping. Sixty patients with demonstrated transition from LVSP to ns-LBBP during dynamic manoeuvers were compared to 44 patients with the same transition during lead screwing-in. Average shortening in paced V6-RWPT was similar among study groups (17.3 ± 6.8 ms vs. 18.8 ± 4.9 ms for transition during dynamic manoeuvres and lead screwing-in, respectively; p = 0.719). Paced V6-RWPT and aVL-RWPT, V6-V1 interpeak interval and the recently described LBBP score, were also similar for ns-LBBP morphologies in both groups. LVSP morphologies showed longer V6-RWPT and aVL-RWPT, shorter V6-V1 interpeak interval and lower LBBP score punctuation, without differences among the two QRS transition groups. V6-RWPT < 75 ms or V6-V1 interpeak interval > 44 ms criterion was more frequently achieved in ns-LBBP morphologies obtained during lead screwing-in compared to those obtained during dynamic manoeuvres (70.5% vs. 50%, respectively p = 0.036). During LBBAP procedure, QRS transition from LVSP to ns-LBBP can be observed as the lead penetrates deep into the IVS with interrupted pacemapping. Shortening of at least 10 ms in paced V6-RWPT may serve as marker of LBB capture.

Permanent Pacemaker Use in Transcatheter Aortic Valve Replacement: Real World Experience from the National Inpatient Sample

Background: Transcatheter Aortic Valve Replacement (TAVR) is associated with conduction abnormalities requiring permanent pacemaker implantation (PPMI). Data regarding predictors for PPMI following TAVR is scarce. Methods: This is a retrospective study utilizing the 2017 National In-Patient Sample (NIS). Patients who underwent TAVR and PPMI during the same admission were identified using appropriate ICD-10 codes, as were patients with left bundle branch (LBBB), right bundle branch (RBBB), and first-degree AV delay (AVB). Patients were split into two groups based on PPMI. The groups were compared using univariate and multivariate analyses after adjusting for age, gender, race, comorbidities, insurance status, and Charlson comorbidity index (CCI). Secondary outcomes included factors influencing length of stay (LOS) and total charges incurred. Results: In 2017, 54,175 (57.6% males) patients underwent TAVR. There were 8,067 patients with LBBB, 2,402 with RBBB, and 2,905 with AVB at baseline. A 4170 total of patients (55.2% males) required PPMI. Patients requiring PPMI were older (80.5 vs 79.6 years, p=0.001). On multivariate analyses, baseline RBBB, LBBB, hypertension (HTN), CCI 2, and CCI &gt;/=3 predicted PPMI (aOR 4.82, p&lt;0.001; aOR 1.63, p&lt;0.001; aOR 1.21, p=0.013, aOR 1.53, p=0.022 and aOR 1.46, p=0.031 respectively). On multivariate analyses, patients who underwent PPMI had significantly higher LOS (aOR 2.18, p&lt;0.001) and incurred higher total charges (USD 278,000 vs USD 204,920; p&lt;0.001). Conclusion: In this cohort, RBBB, LBBB, HTN, and increased CCI predicted PPMI after TAVR. Further studies are required to corroborate our findings.