bluuebunny/crossref_metadata_2025_split huggingface dataset:
In-vivo mapping of human polymorphic ventricular tachycardia in Brugada syndrome
Authors: Pannone L , Della Rocca D G , Vergara P , Sorgente A , Overeinder I , Bala G , Almorad A , Stroker E , Pappaert G , Sieira J , La Meir M , Brugada P , Chierchia G B , Sarkozy A , De Asmundis C 
Published: May 2024

Abstract

Background/introduction
Brugada syndrome (BrS) is associated with ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Different mechanisms have been described for human PMVT, including epicardial drifting of rotational activity before stabilization on the apex.

Purpose
The aim of this study is mapping human PMVT mechanisms in BrS with ECG imaging (ECGI) in-vivo.

Methods
All BrS patients, were prospectively enrolled between 1992 and 2022. Inclusion criteria for the study were: 1) BrS diagnosis; 2) PMVT mapped with ECGI during thoracoscopic epicardial right ventricle outflow tract ablation. PMVT was adjudicated if a changing QRS pattern was present. Phase mapping was performed for each PMVT. All maps were imported on a dedicated software and analyzed offline. Left anterior descending coronary artery was added, based on CT scan reconstruction as a reference for the interventricular septum (in grey in Figure 1). Phase maps were performed using the Hilbert transform on detrended signals and the phases of wavefront propagation were color-coded. Rotational activity was defined as a continuous progression of phase from -π to +π around a phase singularity point. Focal activity was defined as a wavefront that appears de novo, without arising from another wavefront and spreading from its origin.

Results
A total of 21 BrS patients with VF were analyzed and 2 patients (9.5%) were found with PMVT. A total of 2 episodes of PMVT were mapped (one for each BrS patient) with a duration of 2.9 s and 1.3 s, respectively. Both PMVT had spontaneous initiation and termination. The mean number of rotational activities was 2.45 ± 0.07, with a mean of 2.9 ± 0.71 rotations on the apex and 0.8 ± 1.13 rotations on the septum. No other rotational activity was observed. There were 2 and 1 focal activities on the septum, respectively. No other focal activity was observed. The phase mapping of both PMVT episodes was consistent with the mechanism shown in Figure 1. In the first phase of PMVT (negative QRS) a stable rotor (white arrow) is found over ventricular apex (Figure 1, Panels A-D). In Figure 1, Panel E a septal activity appears (yellow arrow). The reduction of QRS voltage is secondary to a fusion between septal (yellow arrow) and apical (white arrow) rotational activities (Figure 1, Panels F-G). In the second phase of PMVT (positive QRS) a stable focal activity (yellow arrow) is found over the ventricular septum (Figure 1, Panels H-J).

Conclusion
In patients with BrS, change in the QRS pattern during PMVT is secondary to a fusion between rotational septal and apical activities.Figure 1
Automated template matching versus conventional pace-mapping during pvc ablation: results from a randomized controlled trial
Authors: Schulz N , Steven D , Sultan A , Van Den Bruck J H , Woermann J , Schipper J , Scheurlen C , Dittrich S , Filipovic D , Erlhoefer S , Lueker J 
Published: May 2024

Abstract

Background
Pace-mapping has an important role in the ablation of idiopathic premature ventricular contractions (PVC). There is a software with an automated algorithm annotating and visualizing template matching points. Automated template matching (ATM) facilitates the matching process and may thus shorten the procedure duration and potentially increase ablation success.
In this randomized study we evaluate whether the use of the automated template matching (ATM) software compared to conventional pace-mapping (PM) influences outcomes and periprocedural parameters in patients undergoing PVC ablation.

Methods
The study was performed as a prospective randomized controlled single-center clinical trial. Patients scheduled for de-novo PVC ablation were included and randomly assigned to either PVC ablation using the ATM algorithm (ATM) or conventional pace-mapping (PM).
The primary endpoint was the procedural outcome represented by the PVC burden after three and twelve months. Secondary endpoints were periprocedural parameters including procedure duration, number, and duration of radiofrequency application (RFA), fluoroscopy (FS) dose, and duration.
An interim analysis was predetermined after 72 patients had completed their three-month follow-up.

Results
After the interim analysis, the study was prematurely ended for futility.
At termination of the trial 108 patients had been included. 18 patients dropped out of the study. Out of the remaining 90 patients, 88 patients (97%) have completed the three-month follow-up, and 73 patients (81%) the twelve-month follow-up. The mean age at the time of procedure was 57.3 years [18-82] without significant differences between both groups.
Before ablation, the mean PVC burden was 20.8% [0.1-55.0] (ATM: 20.8% [3.0-55.9]; PM: 20.7% [0.1-44.0]; p=0.959). At 3-month follow-up, the mean PVC burden in both groups (ATM: 4.7% [0-29.4]; PM: 3.6% [0-45.7]; p=0.512) showed no significant difference between the groups. At 12-month follow-up the mean PVC burden in both groups (ATM: 3.8% [0-31]; PM: 2.2% [0-25.6]; p=0.282) also resulted in a non-significant difference between the groups.
Furthermore, the procedural parameters (table) did not differ significantly between both groups.

Conclusion
In this randomized trial, the use of the automated template matching software did not result in improved outcomes or procedure-related parameters. Conventional pace-mapping appeared to be equally effective compared to the automated template matching software as used in this study.Table secondary endpoints
Bipolar catheter ablation of left ventricular summit PVC
Authors: Woermann J , Van Den Bruck J , Schipper J , Filipovic K , Ackmann J , Erlhoefer S , Pavel F , Scheurlen C , Dittrich S , Sultan A , Steven D , Lueker J 
Published: May 2024

Abstract

Background
Premature ventricular contractions (PVC) arising from the left ventricular summit are a challenging arrhythmia to manage, often refractory to conventional radiofrequency ablation. This study aimed to investigate the effectiveness of bipolar ablation as a therapeutic option for PVCs originating from this anatomically complex region.

Methods
We conducted a retrospective analysis of a prospective ablation registry to identify patients with recurrent, symptomatic PVCs originating from the left ventricular (LV) summit who underwent bipolar ablation. Bipolar ablation involved the use of two ablation catheters, delivering radiofrequency energy from opposite sides of the summit. The catheters were connected by a dedicated adapter, allowing to connect one ablation catheter in position of a return electrode. Procedural success was defined as the elimination of PVCs during the procedure and freedom from PVCs on follow-up monitoring. Results were compared to a similar patient group who had received unipolar ablation of summit-PVCs.

Results
A total of 12 pts received bipolar ablation between July 2022 and October 2023. Three pts underwent ablation for VT and were excluded. A total of 9 pts (mean age 57±18 years, n=7 [78%] male, BMI 28±5kg/m2) were included in the analysis. All but one had a history of a previous unsuccessful ablation attempt (median 1 [1-2]). In a group of 33 patients undergoing unipolar ablation 8 (32%) had received ≥ 1 previous ablation and were included in the analysis. Baseline parameters did not differ between groups. The acute procedural success rate for bipolar ablation was 89% in bipolar pts and 75% in unipolar pts, with a mean procedural time of 173±33 min, a mean fluoroscopy time of 14±9 min (158±55 min [p=0.478] and 14±12 min [p=0.995] for unipolar pts). Bipolar ablation was performed between the LVOT and RVOT in 6, and between LVOT and the distal CS in 6 pts with 25-35 W. No major complications were detected in bipolar pts while one non-fatal tamponade occurred in the unipolar pts group. Follow-up data at 97 [93-269] days revealed a sustained reduction in PVC burden in bipolar pts (from 18±13% to 7±9%; p=0.026) while unipolar ablation did not show a significant burden reduction (15±6% to 11±10%; p=0.382). The success rate of a relative burden reduction &gt;50% did not differ significantly between the groups (bipolar: 6 pts [67%] 3 pts [38%]; p=0.347).

Conclusion
Bipolar ablation offers an effective and safe therapeutic approach for PVCs originating from the LV summit. It significantly reduced PVC burden in this analysis. The data suggest that a repeat procedure after a failed summit PVC ablation should only be performed if bipolar ablation is available during the second procedure. Larger studies are warranted to confirm efficacy and safety of this ablation method.
The evaluation of the efficacy of automated peak frequency annotation algorithm for the identification of critical isthmus of ventricular tachycardia and deceleration zones
Authors: Zekeriyeyev S , Coteli C E M , Yorgun H I K M E T , Aytemir K U D R E T 
Published: May 2024

Abstract

Background
Substrate modification techniques have widely been adopted due to hemodynamic instability and non-inducibility of clinical ventricular tachycardia (VT). Accurate annotation of local near field EGMs is paramount to better evaluate the ventricular substrate. Furthermore, annotation of late potentials (LP) necessitates substantial manual input and isochronal late activation mapping (ILAM) involves constant sensitivity adjustments, potentially affecting the accuracy of local ventricular signal representation.

Objective
This study aims to assess the utility of novel automated peak frequency (PF), which aims to determine near field local activity in low voltage regions in the prediction of the CI of scar related reentrant VTs. Furthermore, the effectiveness of automated PF annotation of near field EGMs to identify deceleration zone (DZ) during ILAM was also evaluated.

Methods
A total of 18 patients with scar-related VT were analyzed. In all patients, VT isthmuses were identified based on activation maps and acute termination achieved during radiofrequency ablation. Automated PF annotation using Ensite X system (Abbott) was retrospectively performed in all cases specifically in areas of low voltage with fractioned signals. The accuracy of applying the PF value and automated ILAM map for detecting VT isthmus was also assessed.

Results
Among the study group, 12 (66.7%) had ischemic cardiomyopathy, while 6 (33.3%) had nonischemic cardiomyopathy [3 (16.7%) with arrhythmogenic right ventricular cardiomyopathy, 2 (11.1%) with idiopathic dilated cardiomyopathy, and 1 (5.6%) with hypertrophic cardiomyopathy]. All identified isthmuses were located in areas exhibiting bipolar voltage below 0.5 mV and a PF of 250 Hz with fractionated EGMs Automated NF DZ annotation predicted the VT isthmus in 16/18 (88.9%) of the cases similar to the conventional ILAM with manual adjustment (88.9%).

Conclusion
Using high-density electroanatomical mapping with near field algorithm, a PF cutoff of 250 Hz accurately identified the low voltage regions to predict the CI of VT. In addition, automated annotation of EGMs during ILAM similarly identified the DZs compared with conventional last deflection algorithm with manual adjustments, which were colocalized with CI of VTs.
Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: data from a multicenter experience
Authors: Migliore F , Schiavone M , Pittorru R , Forleo G B , Mitacchione G , Biffi M , Gulletta S , Kuschyk J , Rovaris G , Tilz R , Tondo C , Di Biase L , Gasperetti A , Tarzia V , Gerosa G 
Published: May 2024

Abstract

Background
Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF).Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs, with a lower risk of short- and long-term of device-related complications and infections. Purpose:The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation. Methods:The study population included patients with an S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy. Results:The study population included 30 patients (25 male;median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population.Electromagnetic interference (EMI) occurred in 21 (70%) patients.The primary sensing vector was the one most significantly involved in determining EMI.Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector.The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks due to EMI. Six patients (20%) experienced appropriate shocks.No S-ICD extraction because of need for antitachycardia pacing,ineffective therapy or infection was reported. Conclusions: Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS,and undersensing in the post-operative period following LVAD implantation should be considered.Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.
AV synchrony maintained by a dual-chamber leadless pacemaker in real-world conditions
Authors: Defaye P , Reddy V Y , Ip J E , Doshi R , Exner D V , Canby R , Bongiorni M G , Shoda M , Hindricks G , Neuzil P , Rashtian M , Nevo J , Knops R E 
Published: May 2024

Abstract

Background/Introduction
A dual-chamber leadless pacemaker system has been developed to provide atrial and ventricular pacing and maintain atrioventricular (AV) synchrony. The device demonstrated an ability to maintain consistent AV synchrony in an in-clinic setting when tested through a series of postures and gaits under some programming restrictions. Assessing AV synchrony within real-world conditions is needed to understand the device’s performance under wider variations in activity and over a longer period.

Purpose
Assess a dual-chamber leadless pacemaker’s ability to maintain AV synchrony in an ambulatory environment of daily living under clinically driven programmed settings.

Methods
Implanted de novo subjects, who had at least 25% atrial pacing after 3-months post-implant, wore a 12-lead Holter monitor for a minimum of 24 hours during normal daily activities and completed a symptom diary. Devices were programmed to a dual chamber pacing mode and clinically appropriate settings then interrogated pre- and post-assessment. An independent Core Laboratory evaluated AV Synchrony, based on a configurable sampling window approach at repeated intervals, and defined synchronous cycles based on whether PR intervals fell within a 50 ms margin of the programmed Paced AV Delay.

Results
Among the 50 subjects who were administered the assessment, 48 of their Holters were analyzable (mean age 71.4 ± 10.9 years; 66.7% male), and 47 subjects had paired device interrogation data available. The analyzable population was predominantly indicated for sinus node dysfunction (83.3%) with a minority indicated for AV block (16.7%). The mean ± standard deviation of the programmed paced AV delay was 260.0 ± 47.6 ms, and mean PR interval was 241.4 ± 35.1 ms. An atrial paced beat and ventricular paced beat were each present in 69.5% and 22.5% of the evaluable cardiac cycles in the population, respectively. Mean AV Synchrony was maintained above 97% (95% CI: 95.5, 98.8) in the entire cohort and was sustained at high rates within each sub-population. Device metrics that diagnose the rate of directional implant-to-implant (i2i) communication also confirmed device data average throughput rates above 90% (Picture 1). There were no reported episodes of oversensing, undersensing, loss of capture, or pauses.

Conclusion
Among subjects with standard pacemaker indications, the dual-chamber leadless pacemaker system maintains very high rates of AV synchrony, exceeding i2i throughput, within real-world conditions utilizing clinically appropriate programmed settings.AV Synchrony and i2i by Indication
Feasibility and safety of physiologic pacing post-TAVR
Authors: Pajaro Merino P A , Del Valle Montero J A , Moraleda Salas M T , Luque Perez M , Arce Leon A , Esteve Ruiz I , Carreno Lineros J M , Gomez Menchero A E , Morina Vazquez P 
Published: May 2024

Abstract

Introduction
His-Purkinje conduction system pacing (HPCSP) is an increasingly used technique due to its benefits. The transcatheter aortic valve replacement (TAVR) has in turn been growing and surpasses the number of procedures than surgical aortic valve replacement, however, the main disadvantage with respect to the surgical technique is a greater risk of atrioventricular block and the need for permanent pacing.

Purpose
Assess the feasibility of HPCSP in patients after TAVR, the success rates and the pacing thresholds.

Methods
We present a series of consecutive patients (undergoing TAVI in a single center with need for subsequent ventricular stimulation (n=58), from March 2019 to July 2023, performing HPCSP as the first stimulation option.

Results
We achieved HPCSP in 49 of 58 patients (84.5%). Patients had a mean age of 81.5 years, 60.3% men, mean LVEF 53.82 ± 12.4%. His bundle pacing (HBP) was successful as first option in 41.4% of cases, and left bundle branch area (LBBAP) in 43,1 % of cases (73.5% of the remaining 58.6%) , while the other 9 patients (15.5%) were pace conventionally at right ventricle, septal or wireless. HBP thresholds and R-wave amplitudes at implantation were 0.99 ± 0.72 at 0.5 ms, 4.59 ± 3.67 mV), remaining stable at follow-up at 1 month (1.16 ± 0.92 at 0.5 ms, 4.17 ± 3.97 mV),. Average QRS width was40.8 ± 21.3 ms pre and 122.43 ± 15.2 ms post). LBBAP pacing thresholds and R-wave amplitudes were(0.89 ± 0.45 at 0.5 ms, 6.145 ± 5.3 mV)at implant, and were stable at follow-up at 1 month (0.75 ± 0.3 at 0.5 ms, 8.41 ± 5.8 mV), with no improvements on QRS (129.75 ± 21.01 ms pre, 134.13 ± 17.34 ms post).
During a mean follow-up of 23 months. There has been no acute elevation of thresholds or need for reintervention. Only 6 patients have died (10.3%), 2 of them (33%) from cardiovascular causes.

Conclusions
HPCSP is feasible as a routine techniquein patients after TAVR who need a pacemaker implantation, with low pacing thresholds, which remained stable on the follow-up.
Single-center experience with His bundle lead implantation: success rate, implantation method optimization, and lessons learned in 426 patients
Authors: Foeldvary M , Grigoryan A , Tribunyan S , Bachour C , Feldmann T , Israel C 
Published: May 2024

Abstract

Background
Conduction system pacing (CSP) is increasingly used to avoid the development of pacing-induced cardiomyopathy in patients who require a high amount of ventricular pacing. His bundle pacing (HBP) is considered as ideal to achieve the narrowest paced QRS and optimal synchronization in patients with intrinsic narrow QRS or right bundle branch block but also as difficult at implantation.

Purpose
We analyzed our experience with HBP in terms of time and effort, pacing and sensing results, success rate, and lessons learned for optimization over a time period of 7 years.

Methods
All consecutive patients in whom HBP was attempted between 6/2016 and 11/2023 were included in this analysis. Implantations were performed using a pacing system analyzer (PSA) with high-resolution electrograms (EGMs). Data on implantation success [selective or non-selective HBP, left bundle branch area pacing (LBBAP)], sensing and pacing parameters, achievement of His bundle current of injury (coi), duration of implantation and fluoroscopy were collected prospectively. These results were compared for the 1st, 2nd, 3rd and 4th quartile of implantations and reasons for improvement or deterioration were analyzed.

Results
HBP was attempted in 426 patients (78±11 years, 38% female, 90% AV block, left ventricular ejection fraction 54±10 %, 81 single-, 286 dual-, 46 triple-chamber pacemakers, 2 dual- and 11 triple-chamber ICDs) and was successful in 404 patients (95%): 182 non-selective HBP, 206 selective HBP, and 16 LBBAP. R wave amplitude was 4.5±3.5 mV, pacing threshold 1.1 ± 0.6V/1.0 ms. In 16% of patients, a ventricular back-up lead was implanted. A His bundle coi was achieved in 61% of patients. The implantation duration was 92±43 min, fluoroscopy duration 10±8 min. Success rate increased from 89% in the 1st to 99% in the 4th quartile. Improved implantation success was associated with using a stiff 3D steerable sheath, implantation site at the distal His bundle, and an increased number of screw-in turns until a His bundle coi was visible.

Conclusions
Establishing an implantation routine with 1) a PSA and high-resolution EGMs, 2) use of a stiff 3D steerable sheath, 3) implantation at the distal His bundle with myocardial capture (non-selective HBP) as a back-up, and 4) an increased number of screw-in turns of the lead tip until a His bundle coi is achieved, HBP implantation can be facilitated and results optimized to a highly acceptable implantation effort and a success rate &gt;95%.