bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of pacing output and cycle length on QRS morphology in ablation of premature ventricular contractions (PACE-MAP-trial)
Authors: Van Den Bruck J , Woermann J , Sultan A , Filipovic K , Scheurlen C , Erlhoefer S , Dittrich S , Schipper J , Steven D , Lueker J 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Pace mapping is an established technique to localize the origin of premature ventricular contractions (PVC). The QRS morphology induced by endocardial pacing is compared with a previously recorded template of the target arrhythmia. Based upon historic in-vitro models pacing at the arrhythmia’s coupling interval (CI) and stimulation threshold has become the gold standard in pace mapping.

Purpose
There is a paucity of data supporting pacing at the CI and stimulation threshold as the gold standard for pace mapping. In this prospective study, we sought to assess systematically the impact of variations of pacing output and cycle length on the resulting QRS morphology during pace mapping in the context of PVC ablation.

Methods
All patients undergoing ablation of idiopathic PVC were prospectively enrolled in this study. Pace mapping was performed using four different parameter settings: (1) A predefined fixed burst at maximum output (10V/2ms), (2) fixed burst at stimulation threshold, (3) coupling interval at maximum output and (4) coupling interval at stimulation threshold. Pacing cycle length (PCL) of the fixed burst was defined as follows: For a CI≤450ms = PCL of CI+100ms and for a CI≥450 = PCL of CI-100ms. Using an automated waveform comparison algorithm (Bard® LabSystem™ PRO software; Boston Scientific, MA, USA), the resulting QRS complexes were matched with the clinical PVC, and with the gold standard. For every parameter setting the mean of the matching percentage of three QRS complexes entered the analysis.

Results
We report data of the first 47 consecutive patients (57±18 years, 64% male) enrolled in this ongoing study between May 2021 and September 2022. The pacing protocols were performed at 75 different sites: 6/75 epicardially via great cardiac vein, 38/75 in the RVOT, 23/75 in LVOT and 8/75 in the left ventricular cavity. When comparing the QRS morphologies resulting from the four different pace mapping settings with the clinical PVC, the univariate analysis revealed no difference between groups (p=0.9). Furthermore, there was no difference comparing the paced QRS morphologies at different output and cycle length to the gold standard of threshold pacing at coupling interval (p=0.9).

Conclusion
Variations of pacing output and stimulation cycle length during pace mapping does not affect QRS morphology during PVC ablation. Applying a modern automated waveform comparison tool, no advantage was observed when comparing with the gold standard. It is therefore reasonable to assume, that pace mapping can be performed using an easily applicable setting of a fixed burst at maximum pacing output.
Outcomes of ventricular tachycardia substrate ablation facilitated by preprocedural imaging scar characterization. A prospective multicenter registry
Authors: Penela D , Soto-Iglesias D , Fernandez-Armenta J , Vatasescu R , Zucchelli G , Falasconi G , Marti-Almor J , Franco P , Alderete J , Ordonez A , Viveros D , Bellido A , Francia P , Huguet M , Berruezo A 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Catheter ablation is a recommended therapy for patients with ventricular tachycardia (VT). However, recurrences rate in non-ischemic cardiomyopathy (NICM) patients remains high.

Objectives
To analyze outcomes of VT substrate ablation facilitated by the integration into the navigator system of the preprocedural image scar characterization in both, patients with ischemic cardiomyopathy (ICM) cand NICM.

Methods
One hundred and sixty-five consecutive patients with structural heart disease undergoing scar related left-side VT ablation were included in a prospective European multicenter (5 centers) registry. Pixel signal intensity (PSI) maps from the late gadolinium enhancement-CMR (LGE-CMR) and/or the multi-detector cardiac tomography (MDCT) were imported into the navigator system. Ablation approach (e.g. endo vs epicardial; left vs right side) was based in the scar distribution aiming to eliminate the entire arrhythmogenic substrate. Mapping and ablation were focused in the scar areas. In all patients Scar dechanneling was the substrate ablation technique used.

Results
165 [153 (93%) men, 66+12 y.o, 117 (71%) with ischemic heart disease] patients were included. Pre-procedure CMR was performed in 65 (39%), MDCT in 12 (7%) and both in 88 (53%) patients. VT induction protocol was negative after substrate ablation in 121 (73%) patients, completing the procedure in stable sinus rhythm. Procedure related complication rate was 5.5%. Arter a mean follow-up of 18+19 months, overall survival was 91% and 44 (27%) patients had VT recurrences. There was no difference in VT-free survival in ischemic vs non-ischemic patients (Log rank:0.9), as Figure 1 shows.

Conclusions
A strategy of VT substrate ablation facilitated by the integration into the navigator system of the preprocedural image scar characterization with the aim of eliminate the entire arrhythmogenic substrate results in a low recurrence rate. This approach minimizes the gap in VT-free survival after ablation in patients with ICM and NICM.
Outcomes of functional substrate mapping of ventricular tachycardia (Func-VT) - an international propensity-matched prospective registry
Authors: Bangash F A , Zhong C , Collinson J , Farwell D , Calvo J , Dungu J , Silberbauer J , Hunter R , Santangeli P , Vlachos K , Srinivasan N 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Dynamic substrate changes play a key role in facilitating conduction delay and re-entry in ventricular tachycardia (VT) circuits. Extrastimuli pacing can unmask functional channels demonstrated by dynamic delay, which may play a role in the VT circuit. We have previously developed sense protocol mapping, using short coupled single extrastimuli to delineate areas of maladaptive conduction delay, which play an essential part in VT development.

Purpose
We conducted a multicentre prospective propensity-matched registry of functional VT substrate mapping (Func-VT registry) compared with conventional mapping. Procedure times, mortality, and probability of ATP/ICD shocks were compared to the matched institutional cohort.

Methods
Data prospectively analysed from an international registry of patients undergoing ablation for Ventricular tachycardia. Data was gathered from multiple sites evaluating outcomes of VT ablation using sense protocol mapping and comparing the results with institutional cohort using conventional methods of entrainment, activation mapping, late potential and pace mapping. The date was propensity-matched to age and left ventricular ejection fraction.

Results
There were 41 patients (mean age of 60 years, 80% males, mean ejection fraction: 35%) in the func-VT registry. The median procedure time was 161 minutes compared with 305 in the institutional cohort (p=&lt;0.001). 85% of patients were free from symptomatic VT/ anti-tachycardia pacing or ICD shocks at a median follow-up of 340 days. Mean shocks per-patient burden decreased from 3.5 to 0.08 in the same period (p=0.03). Figure 1 shows survival curves demonstrating the probability of death in the Funct-VT registry patients vs institutional cohort (p=0.011).

Conclusions
VT functional mapping registry provides real-world data regarding acute and long-term outcomes and complications. It shows better outcomes and improved survival in patients who underwent ablation using sense protocol mapping.
Utility of cardiac magnetic resonance in assessing arrhythmic risk in patients with non ischemic cardiomyopathy undergoing biventricular pacing
Authors: Sayed M , El Maghawry M , Hassan M , Kandil H , El Damaty A 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Non-ischemic cardiomyopathy (NICM) is a common heart muscle disorder, which is responsible for approximately one-third of heart failure and is associated with significant morbidity and mortality. Recent data suggested the lack of mortality reduction from adding a defibrillator to cardiac resynchronization therapy (CRT) in all patients with NICM. Myocardial fibrosis detected by cardiac magnetic resonance late gadolinium enhancement (CMR-LGE) can help risk stratify patients who would benefit from adding a defibrillator to CRT in this patient population.

Purpose
We aim at assessing the relationship between the presence of myocardial fibrosis detected by CMR-LGE and the rate of major arrhythmic events (MAE) that included sustained VT, appropriate CRT-D intervention, VF, and SCD in patients with NICM undergoing (CRT) and to compare all-cause mortality and heart failure improvement between patients who receiving CRT-P vs those who receiving CRT-D based on the presence of myocardial fibrosis.

Methods
All consecutive patients with NICM satisfying a guideline directed indication for CRT implantation were included in the study after excluding patients who refused to consent, patients with acute decompensated heart failure and those contraindicated for a CMR. Patients were divided into two groups according to presence of fibrosis in cardiac MRI into (CRT-D/LGE) group and CRT-P/No LGE group and followed along for one year.

Results
Sixty patients were enrolled. Sixteen patients (26.6%) developed MAE during the study duration. Seven patients had myocardial fibrosis (receiving CRT-D as per protocol), while only nine patients had no myocardial fibrosis (receiving CRT-P as per protocol), (41.2% vs 20.9%, P=0.045). Presence of CMR-LGE, regardless the extent and distribution, predicted MAE with odd ratio 2.6 (CI=1.78-8.9, P=0.04). The presence of ≥7.5 % of myocardial fibrosis by CMR was associated with 54 % sensitivity and 100% specificity for MAE in the study population (Figure 1). However, All-cause mortality was significantly higher in the (CRT-P/No LGE) group vs (CRT-D/LGE) group [15 (34.9%) vs 2 (11.8%), P=0.076]. Comparison between both groups regarding symptoms of heart failure, QoL and ejection fraction is shown in Table 1.

Conclusion
In patients with NICM candidates for biventricular pacing, the presence of LGE on CMR, irrespective of the extent or segmental pattern, is independently associated with a major arrhythmic event and is associated with worse heart failure outcome. However, the absence of LGE did not rule out MAE and implanting CRT-P based on lack of fibrosis may result in higher all-cause mortality.
Coronary sinus cannulation as real time anatomical landmark to facilitate left bundle branch area pacing
Authors: Tan K , Ng S , Tan L W , Chia P L , Foo D 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background/Introduction
Left bundle branch area pacing (LBBAP) is an established form of conduction system pacing. Innovative fluoroscopic imaging technique with use of radio-opaque contrast in the right ventricle or using pre-mapped His potential has been advocated as an acquired road map to assist in implantation of LBBAP(1) lead.

Purpose
We aim to explore a different technique by cannulating the coronary sinus (CS) with a sheath and wire to provide real-time anatomical guidance of location of the base of the heart to facilitate more effective LBBAP in a consistent fashion.

Methods
Prior to LBBAP, the body of the CS is cannulated using an AL2 diagnostic angiographic catheter and a 0.035-inch glidewire. The wire is fixated externally, and fluoroscopic image is acquired before proceeding with deployment of the pacing lead onto an optimal ventricular septal position via standard right (RAO 30) and left anterior oblique (LAO 30) views. From August 2021 to October 2022, we enrolled 12 consecutive patients requiring pacemaker for standard indications and explored the CS cannulation method in delivering LBBAP with either steerable catheters or fixed shape sheaths. Thereafter, we analysed and described the success rates, immediate electrical and device parameters, procedural durations, and clinical events.

Results
12 patients were studied. The mean age was 75 ± 13.07 years and 6 (50%) patients were male. 1 (8.3%) was for sinus nodal dysfunction, 10 (83.3%) for atrioventricular block and 1 (8.3%) for atrial fibrillation (AF) control with atrioventricular node ablation. Mean left ventricular ejection fraction was 54.17 ± 8.21 % and baseline QRS was 108.08 ± 23.20ms. LBBAP was successful in all 12 patients based on published criteria with a mean paced QRS duration of 115.25 ± 9.28 ms. The mean total procedure duration was 130.75 +/- 29.84 minutes and mean fluoroscopic duration was 23.17 ± 9.11 minutes. After 1st week post implant, the pacing threshold, sensing, and impedances were stable and acceptable in all the patients. There were no acute complications (e.g. pneumothorax, lead complications, lead dislodgements / perforations) during the periprocedural period.

Conclusion(s)
The CS cannulation method is a feasible, safe, and effective method to to provide real-time anatomical visualisation of the base of the heart. This facilitates the achievement for optimal LBBAP and can be adopted especially in difficult cardiac anatomies or rotated cardiac silhouettes identified on fluoroscopy.
Acute success, stability and safety of left bundle branch area pacing with steerable catheter and stylet-driven leads: A single center experience
Authors: Ng S , Tan K , Chia P L , Foo D 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background/Introduction
Right ventricular apical pacing is associated with adverse outcomes and there is an increasing preference to perform conduction system pacing as it allows for more physiological left ventricular activation. His-bundle pacing is known to be technically challenging and results in higher pacing thresholds and increased rates of lead dislodgement. Left bundle branch area pacing (LBBAP) is an emerging alternative form of conduction system pacing.

Purpose
We aim to study the acute success rates, short-term stability and safety using steerable catheter and stylet-driven (SD) leads for the purpose of LBBAP.

Methods
40 consecutive patients who underwent LBBAP with steerable catheter and SD leads in our center from August 2021 to November 2022 were included in this series. Patients’ demographics, pacing indications, baseline QRS morphologies and duration and left ventricular ejection fraction (LVEF) were analysed. Acute success was defined as achieving stimulation to LV activation time (Stim-LVAT) ≤75ms or incomplete right bundle branch paced morphology in V1 [1, 2]. We also reported any left bundle branch (LBB) potential (if present) and the V6-V1 interpeak interval. All lead parameters and complications in the immediate (1 day) and short-term (1 week and 3-6 months) timeframe were evaluated.

Results
40 patients' age (mean 72.75), gender (male 52.5%), body mass index (mean 24.15) and LVEF (mean 52.75%) were analysed. Pacing indications included sinus nodal dysfunction (25%), atrioventricular block (70%), heart failure with failed cardiac resynchronisation therapy (CRT) (2.5%) and atrial fibrillation (AF) requiring atrioventricular node ablation (2.5%). We achieved an acute success rate of 87.5% (5% with left ventricular septal pacing, 5% converted to conventional right ventricular septal pacing, and 2.5% converted to CRT). Reasons for failure to achieve successful LBBAP include persistent left superior vena cava, high pacing thresholds or inability to burrow lead into the septum for acceptable V1 morphology and Stim-LVAT due to resistance encountered during turning of the lead.
51.43% patients of the successful LBBAP patients had LBB potential present and/or interpeak interval &gt;33ms [3]. Immediate and short-term lead parameters were stable and acceptable in all cases. There were no complications (such as lead dislodgement, rise in lead impedance or threshold) reported during the acute and short-term follow-up.

Conclusion
LBBAP is successful in 87.5% of our cases with use of steerable catheter deploying stylet-driven leads and is proven to be a safe and feasible method for conduction system pacing. Incremental experience with the delivery tools will further improve successful implantation. Longer term follow-up of these patients is needed to determine the long-term safety and stability of LBBAP using steerable catheter and stylet-driven leads.
Physiological stimulation in preserved ejection fraction: A randomized trial
Authors: Rodriguez Queralto O , Gonzalez Matos C , Zaraket F , Jimenez Lopez J , Casteigt B , Rodriguez Gonzalez C , Valles Gras E 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Right ventricular stimulation in the apex (RVAS) produce dysynchrony, leading to left ventricle systolic dysfunction (LVSD) in some cases. Circumstances that can worsen the LVSD are a high burden of RVAS, and the presence of previous LVSD and/or intraventricular conduction disease (IVCD). Direct activation of the specialized conduction system with physiological stimulation (PS) can preserve this physiological pattern and shorten de QRS when the impairment is proximal to the pacing site. Most of the studies with PS has been focused on patients with LVSD, with few and scarce evidences regarding pacients without LVSD.

Objectives and methods
This is a parallel, single blinded, unicentric, randomized trial of patients with preserved of mild reduced left ventricular ejection fraction (LVEF) submitted to a pacemaker implantation due to atrioventricular block (AVB), with previous IVCD (wide QRS) an anticipated high rate of ventricular pacing. Patients were randomized 1:1 to RVAS vs PS and followed for 6 months. Clinical, ECG, echocardiography and analytic parameters were compared. The primary endpoint was the change in the LVEF at 6 months in each group. The secondary endpoints were the changes in the left ventricular end-diastolic diameter (LVEDD), the QRS duration, the pro–B-type natriuretic peptide (NT-proBNP), the NYHA class, and the Minnesota Living with Heart Failure Questionnaire (MLWHFQ) in each group.

Results
The study included 57 patients of 77±9,6 years. Of all patients, 53% were treated with RVAS and 47% with PS. There were 2 patients with crossover to RVAS for technical difficulties and 1 patient with crossover to PS due to apical scar. There were no differences in the basal QRS duration (142.08±20,2 ms), LVEF (58.87±7,2%), NT-proBNP (3336,03±7258,68 pg/ml), or MLWHFQ (22,19±14,68), between both groups (Table 1). Acutely significant differences were observed in the change of QRS duration among groups (+16±29 ms in the RVAS group vs -17±25 ms in the PS group, p&lt;0,001). At 6 months follow-up LVEF showed a non-significant reduction of 0.8±1.1% in the PS group compared to a significant reduction of 5.1±1.7% in the RVAS group (difference 4,26% IC 0,1-8,43 p=0,022). No differences were observed regarding the values of the NT-ProBNP and the MLWHFQ between groups at 6 months (Table 2).

Conclusions
In patients with preserved LVEF requiring pacemaker implantation for AVB, PS shorten the QTS duration and preserves the LVEF compared to RVAS.
Reducing radiation exposure and incision time in pacemakers implantation procedures using direct percutaneous axillary vein puncture
Authors: Vacarescu C , Goanta E V , Cirin L , Lazar M A , Arnautu A , Cozma D 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Radiation exposure during device implantation depends overall on the operator experience but also on the type of venous access, type of device and number of leads implanted.

Purpose
to investigate radiation exposure/incision time for uni/bicameral pacemakers (PM) implantation procedures using direct percutaneous axillary vein puncture without primary fluoroscopy guidance and to assess the safety and the efficiency of this procedure strategy.

Methods
single center retrospective cohort study of patients implanted with unicameral and bicameral PM between January 2020 and December 2020 using direct percutaneous axillary vein puncture. All pts were given detailed explanations and informed consent. Procedural steps were: (I) direct percutaneous axillary vein puncture (anatomical landmarks: 1 or 2 cm medial and parallel to the deltopectoral groove at the level of the coracoid process); obtain separate vein access: 1 or 2 punctures; (II) skin incision and subcutaneous pocket dissection; (III) right ventricle (RV) ± right atrium (RA) lead placement and fixation. We analyzed the following data: fluoroscopy/incision time, dose area product (DAP) and the outcome related to procedure difficulties and complications.

Results
We collected data from 209 consecutive implant procedures; 152 patients (pts) underwent bicameral PM implantation, 57 pts received a unicameral device. All the procedures were done by the same operator (54 yo, 22 years of experience in PM implantation) using axillary access alone (2 years' experience in this technique). In 37 patients (18%) fluoroscopy guided puncture was needed. The mean fluoroscopy time was: bicameral PM 1.2±1.0 min (average incision time: 8.4±5.2 min); unicameral PM 0.4±0.3 min (average incision time: 6.5±4.3 min). The mean DAP was: bicameral PM 0.00358±0.00545 mGy/cm2; unicameral PM 0.00285±0.00449 mGy/cm2. In short term follow-up 1 patient (0.4%) developed pneumothorax and subsequent drainage was needed. Total follow-up period 19.7±4.3 months: at 6 months follow-up 1 patient (0.4%) presented lead fracture; 1 patient with DDD PM (0.4%) presented pocket infection; leads extraction were successful performed and another device was implanted. No other complications were noted.

Conclusion
Single venous access using axillary vein puncture was associated with reduced radiation exposure and decreased incision time. Our data showed a low incidence of complications.