Left bundle branch area pacing in patients with baseline narrow, left, or right bundle branch block QRS patterns: insights into electrocardiographic and echocardiographic features.

AIMS: Left bundle branch area pacing (LBBAP) is a recent technique aiming at preservation of physiological ventricular electrical activation. Our goal was to assess mechanical synchrony parameters in relation to electrocardiographic features during LBBAP performed in routine practice. METHODS AND RESULTS: From June 2020 to August 2021, all patients of our institution with permanent pacemaker implantation indication were eligible for LBBAP. A 'qR' pattern in V1 and a delay from pacing spike to the peak of the R-wave in V6 < 80 ms defined a successful LBBAP. Electrocardiogram and echocardiography were performed during spontaneous rhythm and LBBAP: left ventricular mechanical synchrony (LVMS) parameters using 2D Speckle tracking and interventricular mechanical delay (IVMD) were collected. LBBAP was attempted with success in 134/163 patients (82.2%). During LBBAP, the mean QRS width was 104 ± 12 ms. In patients with left bundle branch block (n = 47), LBBAP provided a significant decrease of QRS width from 139 ± 16 to 105 ± 12 ms (P < 0.001) with reduction of LVMS (53 ± 21 vs. 90 ± 46 ms, P = 0.009), and IVMD (14 ± 13 vs. 49 ± 18 ms, P < 0.001). In patients with right bundle branch block (n = 38), LBBAP led to a significant decrease of QRS width from 134 ± 14 to 106 ± 13 ms (P < 0.001) with no effect on LVMS and a reduction of IVMD (17 ± 14 vs. 50 ± 16 ms, P < 0.001). CONCLUSION: LBBAP in routine practice preserved intra-ventricular mechanical synchrony in patients with narrow and RBBB QRS and improved asynchrony parameters in patients with LBBB.

Can permanent His bundle pacing be safely started by operators new to this technique? Data from a multicenter registry.

BACKGROUND: Right ventricular pacing (RVP) induces ventricular asynchrony in patients with normal QRS and increases the risk of heart failure and atrial fibrillation in long term. His bundle pacing (HBP) is a physiological alternative to RVP, and could overcome its drawbacks. Recent studies assessed the feasibility and safety of HBP in expert centers with a vast experience of this technique. These results may not apply to less experienced centers. We aim to evaluate the feasibility and safety of permanent HBP performed by physicians who are new to this technique. METHODS: We included all patients who underwent pacemaker implantation with attempt of HBP in three hospitals between September 2017 and January 2020. Indication for HBP was left to operators' discretion. All the operators were new for HBP. His bundle (HB) electrical parameters were recorded at implant, 3- and 12-month follow-up. RESULTS: HBP was successful in 141 of 170 patients (82.9%); selective HBP was obtained in 96 patients and nonselective HBP in 45. The mean procedure and fluoroscopy durations were 67.0 ± 28.8 min, and 7.3 ± 8.1 min (3.1 ± 4.1 Gy·cm2 ), respectively. The mean HB paced QRS duration was 106 ± 18 ms. The mean HB capture threshold was 1.29 ± 0.77 V and did not increase at 3- and 12-month follow-up. The ventricular lead revision was required in five patients. Our results showed a rapid technical learning allowing a high procedure success rate (89.8%) after 15 procedures. CONCLUSION: HBP performed by operators new to this technique appeared feasible and safe. This should encourage HBP to be performed in patients expected to experience high RVP burden.

Very long-term outcomes after catheter ablation of atrioventricular nodal reentrant tachycardia: How does cryoenergy differ from radiofrequency?

INTRODUCTION: Either cryoenergy or radiofrequency can be used during atrioventricular nodal reentrant tachycardia (AVNRT) ablation. There are still limited data comparing their respective long-term efficacy (>1 year). This study sought to compare the very long-term outcomes of AVNRT ablation using radiofrequency or cryotherapy. METHODS: We retrospectively included all patients who had undergone a first AVNRT ablation in our institution between January 2010 and December 2017. The primary endpoint was recurrence of documented AVNRT. RESULTS: The study population consisted of 409 patients (274 females; mean age, 49.9 years). Ablation was performed using cryoenergy in 260 patients and radiofrequency in 149. High acute procedural success rate (>98%) was obtained and no permanent AV block was observed using both techniques. During a mean follow-up of 3.3 ± 2.3 years, documented AVNRT recurrence occurred in 24 (9.2%) and 4 patients (2.7%) in the cryoablation (CA) and radiofrequency (RF) group, respectively. The risk of AVNRT recurrence was significantly higher in the CA group as compared with the RF group (hazard ratio [HR] = 3.7; 95% confidence interval [CI], 1.3-5.9). Most of the recurrences after CA occurred between 1- and 6-year follow-up (14/24; 58.3%), with one-third of late recurrences after 3-year follow-up. In multivariable analysis, only Koch's triangle anatomical variant was associated with AVNRT recurrence after CA (HR = 6.7; 95% CI, 2.7-16.3). CONCLUSION: While AVNRT recurrence rates were similar at 1 year of follow-up regardless of the energy used, long-term efficacy appeared higher after radiofrequency ablation. Strikingly, recurrences occured much later after cryotherapy compared with radiofrequency ablation.

Atrial fibrillation detection by the subcutaneous defibrillator: real-world clinical performances and implications from a multicentre study.

AIMS: No data exist concerning the clinical performances of the subcutaneous implantable cardioverter-defibrillator (S-ICD) atrial fibrillation (AF) detection algorithm. We aimed to study the performances and implications of the latter in a 'real-world' setting. METHODS AND RESULTS: Between July 2017 and August 2019, 155 consecutive S-ICD recipients were included. Endpoint of the study was the incidence of de novo or recurrent AF using a combined on-site and remote-monitoring follow-up approach. After a mean follow-up of 13 ± 8 months, 2531 AF alerts were generated for 55 patients. A blinded analysis of the 1950 subcutaneous electrocardiograms available was performed. Among them 47% were true AF, 23% were premature atrial contractions or non-sustained AF, 29% were premature ventricular contractions or non-sustained ventricular tachycardia, and 1% were misdetection. Fourteen percent (21/155) patients had at least one correct diagnosis of AF by the S-ICD algorithm. One patient presented symptomatic paroxysmal AF not diagnosed by the S-ICD algorithm (false negative patient). Patient-based sensitivity, specificity, positive, and negative predictive values were respectively 95%, 74%, 38%, and 99%. Among patients with at least one correct diagnosis of AF, 38% (8/21) had subsequent clinical implications (anticoagulation initiation or rhythm control therapies). CONCLUSION: The S-ICD AF detection algorithm yields a high sensitivity for AF diagnosis. Low specificity and positive predictive value contribute to a high remote monitoring-notification workload and underline the necessity of a manual analysis. Atrial fibrillation diagnosis by the S-ICD AF detection algorithm might lead to significant therapeutic adjustments.

Catheter ablation reduces ventricular tachycardia burden in patients with arrhythmogenic right ventricular cardiomyopathy: insights from a north-western French multicentre registry.

Aims: Studies assessing radiofrequency ablation (RFA) of ventricular tachycardia (VT) in arrhythmogenic right ventricular cardiomyopathy (ARVC) report VT recurrences, but have not evaluated the impact of RFA on relevant clinical events during follow-up. We aimed to investigate relevant RFA outcomes in a multicentric registry. Methods and results: This study included 49 patients with ARVC (46 with definite diagnosis, 3 with borderline diagnosis according to revised Task Force Criteria) who underwent 92 RFA procedures (83 endocardial, 9 combined endo-epicardial) between 1999-2015. Ventricular tachycardia recurrences and VT burden were assessed after each procedure or after the last RFA. Over a mean follow-up of 64 ± 51 months, VT-free survival was 37% at 1 year, 19% at 5 years, and 14% at 10 years. Ventricular tachycardia burden was significantly reduced after one procedure (23 vs. 11 VT episodes/year, P < 0.01) and after the last RFA (14 vs. 2 VT episodes/year, P < 0.01). Over a mean follow-up of 49 ± 52 months, clinical response after the last RFA (freedom from sudden cardiac death, VT requiring hospitalization, or heart transplantation) was 86% at 1 year, 69% at 5 years, and 60% at 10 years. Clinical response was associated with right ventricular dysfunction (RVD) and low numbers of mappable VT before the first RFA. Conclusion: RFA was predominantly targeted at the endocardial surface. Ventricular tachycardia recurrences were common, but few ARVC patients experienced major clinical events during follow-up. Further studies should investigate the benefit of extensive substrate ablation combined with endo-epicardial strategies.

Pacemaker memory in post-TAVI patients: Who should benefit from permanent pacemaker implantation?

BACKGROUND: One of the most frequent complications of transcatheter aortic valve implantation (TAVI) is the occurrence of atrioventricular (AV) conduction disorders secondary to AV node or His bundle injury leading to permanent pacemaker implantation (PPI). The objective was to quantify the rate of ventricular pacing (VP), according to post-TAVI indication for PPI using recorded pacemaker memory. METHODS: From October 2009 to January 2017' all patients who had PPI following TAVI performed at Rouen University Hospital were included. Indications for PPI were: ≥ 1 episode of complete atrioventricular block (CAVB) or 2:1 atrioventricular block, and new-onset persistent left bundle branch block (NOP-LBBB) with either prolonged PR interval (> 200 ms) or HV interval (>70 ms). The primary endpoint was VP percentage at the first pacemaker interrogation (a VP percentage ≥ 1% was considered as significant). RESULTS: Out of 936 TAVI patients (Sapien-3' n = 379 [Edwards Lifesciences, Irvine, CA, USA]; Sapien-XT' n = 513; CoreValve' n = 44, Medtronic, Minneapolis, MN, USA), 87 (9.3%) had PPI. Eighty of these 87 patients were followed-up and analyzed. At the first pacemaker interrogation, a significant VP percentage was observed in 60/80 followed-up patients (75%), in 46/51 patients (90.2%) implanted for CAVB, and 12/23 patients (52.2%) implanted for NOP-LBBB associated with either prolonged PR or HV interval. No clinical predictive factor of significant VP percentage was found. CONCLUSION: In the post-TAVI period, our data support PPI in patients with CAVB even if paroxysmal. Our data also suggest PPI may be considered in patients with NOP-LBBB associated with either prolonged PR or HV interval.

Pentaspline Pulsed Field Ablation Catheter Versus Cryoballoon for Atrial Fibrillation Ablation: Results From a Prospective Comparative Study.

BACKGROUND: Cryoballoon ablation is currently the gold standard technique for single-shot pulmonary vein isolation (PVI). Pulsed field ablation (PFA) has recently emerged as an interesting nonthermal alternative energy for PVI. The purpose of our study was to evaluate the safety and long-term efficacy of PVI using the pentaspline PFA catheter in comparison to cryoballoon ablation. METHODS AND RESULTS: Between January 2021 and December 2022, we included all consecutive patients of our center in whom a first PVI-only procedure was performed using PFA or cryoballoon. The choice of the energy was based on patients' preference between general anesthesia (PFA) and local anesthesia (cryoballoon). The primary end point was freedom from documented atrial arrhythmia recurrence after a 3-month blanking period. A total of 301 patients (paroxysmal atrial fibrillation in 220 patients) underwent a first PVI procedure performed using PFA (n=151) or cryoballoon (n=150). Complete short-term PVI was obtained in 144 of 150 patients (96%) in the cryoballoon group and in all patients of the PFA group (P=0.01). Procedure duration was significantly longer in the cryoballoon group. Transient and persistent phrenic nerve injuries were observed in the cryoballoon group only (13/150 and 2/150, respectively). One-year freedom from atrial arrhythmia was significantly higher in the PFA group compared with the cryoballoon group (87.9% versus 77.7%; adjusted hazard ratio, 0.53 [95% CI, 0.30-0.96]; P=0.037). CONCLUSIONS: This prospective, comparative, real-life study suggested that PFA could overcome safety limitations of cryoballoon with optimal effectiveness. Randomized controlled studies are required to further investigate the potential superiority of PFA over cryoballoon.

His bundle pacing versus left bundle branch area pacing in patients undergoing atrioventricular node ablation: A prospective and comparative study.

BACKGROUND: Pacemaker implantation combined with atrioventricular node ablation (AVNA) is a well-established strategy for uncontrolled atrial arrhythmias. Limited data are available regarding His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in this setting. AIM: To compare the outcomes of HBP and LBBAP in patients undergoing pacemaker implantation combined with AVN in routine clinical practice. METHODS: We prospectively included all patients who underwent AVNA after successful conduction system pacing (CSP) in two hospitals between September 2017 and May 2023. The primary outcome was the 1-year composite of first episode of heart failure hospitalization, symptomatic atrioventricular node reconduction requiring a second AVNA procedure, lead revision or death from any cause. RESULTS: A total of 164 patients underwent AVNA following successful CSP (68 HBP and 96 LBBAP). Mean pacemaker implantation and AVNA procedure times were shorter in the LBBAP group than the HBP group (46±18 vs 59±23min; P<0.001 and 31±12 vs 43±22min, respectively; P<0.001). Complete atrioventricular block was more frequently obtained in the LBBAP group (88/96 patients [92%] vs 54/68 patients [79%]; P=0.04). One-year freedom from the composite outcome was more frequent in the LBBAP group (89.7% vs 72.9%; hazard ratio 0.32, 95% confidence interval 0.14-0.72; P=0.01). The strategy was similarly effective in both groups with a significant improvement in NYHA class and left ventricular ejection fraction. A secondary pacing threshold elevation >1V occurred only in the HBP group (11%). CONCLUSION: In this prospective, comparative study, LBBAP provided better 1-year outcomes than HBP.

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

BACKGROUND: 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. OBJECTIVE: 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. METHODS: We prospectively included all patients who had undergone AVNA after HBP in 3 different hospitals between 2017 and 2022. RESULTS: 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). CONCLUSION: 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.