bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploration of peak frequency mapping for ventricular tachycardia ablation. Identification of critical isthmus zones during substrate mapping
Authors: Mayer J , Al-Sheikhli J , Patchett I , Marshall L , Niespialowska-Steuden M , Siang R , Roca Luque I , Silberbauer J , Dhanjal T 
Published: May 2024

Abstract

Background/Introduction
The ability to classify and differentiate between near field and far-field components of intracardiac signals is a key element in identifying critical arrhythmogenic substrate during ventricular tachycardia (VT) ablation. Near Field algorithms based on omnipolar electrograms enable detection and automation of true localised signals providing unique insights into substrate characteristics. This novel feature identifies localised signal peak frequency (PF) which can be displayed across different voltage ranges.

Purpose/Aims
The significance of PF mapping in the context of VT ablation is limited and its utility in the identification of the critical diastolic isthmus zone (IZ) is not known. The aim of this study is to explore the utilisation of PF mapping during VT ablation and evaluate whether significant differences in PF occur within areas of interest and critical components of the VT circuit during substrate mapping.

Methods
All patients underwent VT ablation using the EnSite™ X mapping system with the HDGrid omnipolar mapping catheter. Only cases with both high density sinus rhythm (SR) substrate maps and VT activation maps with clear identification of the IZ were included. VT activation and propagation maps were generated and the diastolic IZ was superimposed onto the SR substrate map. PF analysis was performed retrospectively. Surface area, omnipolar voltage and PF of the maps were measured in the SR substrate maps and co-localised with the critical IZ of the VT circuit as identified in the VT activation maps. Analysis of PF was conducted across different voltage ranges: healthy myocardium (&gt;1.5mV), scar (1.5-0.5mV) and dense scar (0.5-0.1mV). Sensitivity and specificity measurements were made within segments of the IZ and non-isthmus zones and depicted as ROC curves.

Results
55 patients underwent VT ablation over a 12-month period, with a total of 18 fulfilling the inclusion criteria. Mean age was 70 (±12.5years) with an average ejection fraction of 36%. The overall PF of the SR substrate maps was 121.85±26.85 Hz, compared to 162.22±46.22Hz within the IZ (p=0.002). Within the low voltage scar region, the overall PF was 120.86±33.24Hz compared to 188.32±81.36Hz within the IZ (p=0.003). No significant difference in PF was observed within healthy myocardium (112.70±52.06 Hz) compared to components of the IZ within the &gt;1.5mV range (157.61±136.11Hz), p=0.207. The AUC for PF within the overall substrate map and co-localisation with the IZ was 0.67, and 0.73 within low voltage zones (&lt;1.5mV).

Conclusions
PF mapping may identify critical components of the VT circuit during SR substrate mapping and its utilisation may compliment established substrate mapping approaches. PF guided ablation strategies require further evaluation in future prospective studies.
Prevention of venous thromboembolism after right heart-sided electrophysiological procedures: results of an EHRA survey
Authors: Mugnai G , Farkowski M , Tomasi L , Roten L , Migliore F , De Asmundis C , Conte G , Boveda S , Chun J K R 
Published: May 2024

Abstract

Background
Limited data are available regarding venous thromboembolism (VTE), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE), following right-sided ablations and electrophysiological (EP) studies. Compared to left-sided procedures, no guidelines on antithrombotic management strategies for the prevention of DVT and PE are available.

Purpose
The main purpose of the present European Heart Rhythm Association (EHRA) survey is to report the current management of right-sided EP procedures, focusing on anticoagulation and prevention of VTE.

Methods
An online survey was conducted using the EHRA infrastructure. A total of 244 participants answered a 19-items questionnaire on the periprocedural management of EP studies and right-sided catheter ablations.

Results
The right femoral vein is the most common access for EP studies and right-sided procedures. An ultrasound-guided approach is employed by more than 2/3 of respondents. Intravenous heparin is not commonly given by the majority of participants. About 1/3 of participants (34%) routinely prescribe VTE prophylaxis during (mostly aspirin and low molecular weight heparin) and 1/4 of respondents (25%) commonly prescribe VTE prophylaxis after discharge (mostly aspirin). Of note, respectively 13% and 9% of participants observed at least one DVT and one PE related to right-sided ablation or EP study within the last year in their center.

Conclusion
The present survey shows that only a minority of operators routinely gives intraprocedural intravenous heparin and prescribes VTE prophylaxis after right-sided EP procedures. Compared to left-sided procedures like AF ablation, there are no consistent systematic antithrombotic management strategies.
Electrophysiologic characteristics and outcomes of atrial tachycardia ablation after mitral valve surgery
Authors: Kilic S , Coteli C , Yorgun H , Aytemir K 
Published: May 2024

Abstract

Background
Atrial tachycardia (AT) is a commonly encountered rhythm disorder in patients with mitral valvular (MV) surgery. Radiofrequency (RF) ablation is the preferred therapeutic option in symptomatic patients.

Purpose
We aimed to evaluate the characteristics and ablation outcomes of AT in patients with previous mitral valve (MV) surgery.

Methods
A total of 100 symptomatic patients [mean age: 56 ±12, gender: 56 (56%) female] with documented AT were enrolled. Activation mapping was performed during tachycardia in all patients as well as entrainment mapping when needed. Voltage mapping was performed in sinus rhythm in the related atrium. Low voltage areas and signals with continuous-fragmented morphology were also tagged.

Results
In 127 procedures, a total of 158 ATs were documented [59 (37.3%) ATs were right-sided, 95 (60.1%) ATs were left-sided and 4(2.5%) AT was biatrial]. Mean number of ATs per procedure was 1.2±0.6. Macroreentry was the primary mechanism in right and left atrium (83.1% and 63.1%, respectively). Cavo-tricuspid isthmus (CTI) dependent macroreentry was the most frequent mechanism in right ATs whereas perimitral reentry was the most common mechanism in left ATs. Atrial low voltage zones comprised 45.5±25.1 % of total left atrium. The acute procedural success was 95.2%. Freedom from ATa after index procedure was 80% at 12 months and 65.6 % at 24 months. After multiple procedures, freedom from ATa was 77% during the mean follow-up duration of 39.7 ± 27.2 months.

Conclusion
Left ATs are more common compared to the right ATs and macroreentry is the major mechanism in both right & left ATs. RF ablation of ATs has favourable long-term outcomes in patients with MV surgery.
Strategies for recurrent atrial fibrillation in patients despite durable pulmonary vein isolation
Authors: Ackmann J , Woermann J , Lueker J , Van Den Bruck J H , Erlhoefer S , Scheurlen C , Pavel F , Filipovic K , Schipper J H , Steven D , Sultan A 
Published: May 2024

Abstract

Background
Pulmonary vein isolation (PVI) is the cornerstone in treatment of atrial fibrillation (AF). Despite initially successful PVI patients experience recurrence of AF mostly due to reconnection of pulmonary veins (PVs). However, a certain number of patients presents with recurrent AF despite durable PVI. The optimal ablation strategy for these patients has yet to be discerned.

Aim
The aim of this study was to compare outcomes for different ablation strategies for recurrent AF despite persistent PVI.

Methods
All redo procedures for recurrence of AF from 01/2016 – 6/2022 at our center were analyzed. Only patients with proven durable PVI (entrance/exit block and high density (HD) mapping) were included. Patients were excluded, if re-PVI or right atrial ablation was necessary. In all procedures (HD) 3-D mapping and radiofrequency ablation were performed. Ablation strategy was at operators’ discretion. A 12-month follow up (FU) was obtained.

Results
A total of 405 left-atrial procedures for the recurrence of AF were analyzed. In 85 (21.0%) procedures all PVs were still isolated. Of these 30 patients (35.3 %) were female and 70 patients (82.4 %) suffered from persistent AF. In 49 patients (57.6 %) LA scar was detectable (85.7 % persAF). The ablation strategies consisted of: roof line (n=9; 10.6 %), left atrial anterior line (n=8, 9.4 %), roof line and left atrial anterior line (n=8, 9.4%), roof line and left atrial inferior line (n=18, 21.2 %), box lesion (n=6, 7.1 %), other left atrial ablation lines (n=20, 23.5 %) and substrate modification (CFAE and substrate encirclement) (n=16, 18.8 %). In patients with PAF (n=15), 3 patients received a roof line (20.0 %), 3 patients received the latter and left atrial inferior line (20.0 %), 5 patients received other left atrial ablation lines (33.3 %) and 4 patients received substrate modification (CFAE and substrate encirclement) (26.7 %). After a mean follow up of 401 +/- 125 days 55.3 % (n=47) of patients were free from any atrial arrhythmia (roof line 77.8 +/- 15 %, left atrial anterior line 87.5 +/- 13 %, roof line and left atrial anterior line 37.5 +/- 18 %, roof line and left atrial inferior line 50 +/- 12 %, box lesion 83.3 +/- 17 %, other left atrial ablation lines 45.0 +/- 11 %, substrate modification (CFAE and substrate encirclement) 43.8 +/- 13 %, p=0.122), 35.3 % (n=30) showed recurrence of AF (p=0.287) and 9.4 % (n=8) showed atrial tachycardia (AT) (p=0.693). None of the ablation strategies led to a significantly superior outcome.

Conclusion
In patients suffering from recurrence of AF despite durable pulmonary vein isolation different substrate modification strategies did not show any superiority for one or the other. Despite the necessity of additional ablation beyond PVI the optimal ablation strategy needs to be yet determined to improve outcome for redo procedures.
Endocardial ablation of ganglionated plexus for the treatment of carotid sinus syndrome
Authors: Minguito Carazo C , Rodriguez Manero M , Martinez Alday J D , Martinez Sande J L , Garcia Seara J , Fernandez Lopez X A , Gonzalez Ferrero T , Elices Teja J , Gonzalez Melchor L , Shangutov O , Gonzalez Juanatey J R 
Published: May 2024

Abstract

Introduction
Carotid sinus syndrome (CSS), characterized by exaggerated vagal responses leading to asystolic pauses with carotid sinus massage (CSM), often necessitates pacemaker implantation. This study investigates cardioneuroablation (CNA) as an alternative management strategy for CSS.

Methods
Prospective study of consecutive patients referred for CNA. All patients underwent CSM, atropine test, 24-hour Holter monitoring and SF-36 quality of life questionary before the procedure and at 6 months. The objective of the study was to assess syncope free survival, grade of cardioinhibition with CSM and heart rate variation (HRV) and quality of life after the procedure.

Results
A total of 13 patients (84.6% male, mean age 63.8 ± 12.3 years) were included. After a median follow-up of 9.2 (8.6-14.3) months, none of the patients experienced syncope (0%) and none of the patients required pacemaker implantation. After the procedure all the patients had a negative CSM and only one patient (7.7%) had a positive CSM at 6 months (Figure 1). There was an improvement in the energy and health change items in the SF-36 quality of life questionary. There was a reduction in HR increase in the atropine test at 6 months (pre-CNA: 66% (52-84) vs. post-CNA 27.4% (21.9-90.9); p=0.027) and in most of the 24-hour Holter monitoring HRV parameters (Figure 2).

Conclusions
Cardioneuroablation emerges as a promising and effective alternative to pacemaker implantation in managing cardioinhibitory CSS. Further research is warranted to solidify these findings and explore the long-term effects of CNA in this scenario.Maximum RR interval with CSMHeart rate increase in the atropine tes
One year of atrial fibrillation ablation using pulsed-field pentaspline catheter - learning curves based on a single centre experience
Authors: Hozman M , Osmancik P , Herman D , Hassouna S , Karch J , Vesela J , Poviser L , Filipcova V , Hozmanova J , Znojilova L 
Published: May 2024

Abstract

Introduction
Pulsed-field ablation (PFA) represents a novel nonthermal strategy for ablation of atrial fibrillation (AF). As the technology has recently emerged in routine clinical praxis, only limited data on learning curves exist so far. Hereby, we present data from our centre regarding learning curves after the first year of using PFA.

Methods
The ablation procedure was performed under deep sedation or general anaesthesia in patients with paroxysmal or persistent AF. No 3D mapping system was used, procedures were guided by fluoroscopy and intracardiac echocardiography. For ablation itself, a pantaspline over-the-wire catheter with a steerable sheath was used. The following parameters were analysed over the course of time: procedure time, left atrial (LA) catheter dwelling time, total fluoroscopy time, and complications. Patients who received pulmonary vein isolation (PVI) alone and those with another additive set of lesions (PVI+) were analysed separately. Procedural parameters of the first and the last 20 patients of each group were compared for statistical significance.

Results
A total number of consecutive 159 patients (mean age 63.20 ± 10.51 years, 69.40 % males) were included in the analysis (PVI N = 73 (45.91 %), PVI+ N = 83 (54.09 %)). Procedures were performed by 3 certified electrophysiology specialists usually in random teams of 2 operators. The mean procedure time was 62.59 ± 23.09 min (PVI 59.64 ± 27.27; PVI+ 65.09 ± 18.64 min, P = 0.15). Over time, there was a non-significant decrease in PVI group (60.30 ± 17.44 vs. 52.75 ± 16.33 min, P = 0.16), but no difference in PVI+ cohort (67.85 ± 13.31 vs. 67.65 ± 28.88 min, P = 0.97). The mean LA catheter dwelling time was 39.84 ± 13.52 min (PVI 35.04 ± 10.20 min; PVI+ 44.33 ± 14.72 min, P &lt;0.001). Non-significant shortening of the LA dwelling time was observed in PVI patients (36.56 ± 8.0 vs. 33.37 ± 9.58 min, P = 0.29). In contrast, the LA dwelling time in the PVI+ group became non-significantly longer (42.93 ± 10.62 vs. 48.56 ± 22.28 min, P = 0.39). The mean fluoroscopy time was 9.28 ± 3.66 min (PVI 8.65 ± 3.04; PVI+ 9.80 ± 4.05 min, P = 0.043). Importantly, fluoroscopy time decreased significantly in both groups over time (PVI: 10.63 ± 3.51 vs. 6.95 ± 2.45 min, P &lt;0.001; PVI+: 12.82 ± 4.99 vs. 9.13 ± 4.16 min, P = 0.017). Regarding complications, we observed one pulmonary oedema requiring orotracheal intubation and mechanical ventilation in the early period. Other complications were related to the femoral puncture site.

Conclusion
Over the course of time with the new PFA technology, we observed a significant decrease in total fluoroscopy time. However, the change in total procedure and LA dwelling time did not reach statistical significance.
Using the impedance map to identify non-conductive structures during cavo-tricuspidal isthmus ablation
Authors: Sciarroni R , Notarangelo M F , Crocamo A , Bearzot L , Gonzi G , Fioravanti M , Niccoli G , Ardissino D 
Published: May 2024

Abstract

Background
The ablation of the cavo-tricuspidal isthmus (CTI) is often affected by the anatomical variability of structures made of non-conductive tissue (NCS): the Eustachian valve, tricuspid valve leaflet and Tebesio's valve, the presence of which may be associated with failure of the isthmic block despite a large number of erogations and post-ablation recurrences. Since these structures have different conductive properties from atrial tissue, it is plausible that they are characterised by their own tissue impedance, and can therefore be identified through an impedance map.

Objectives
The objectives of the study were: 1) to characterise CTI by impedance map, in order to identify NCS; 2) to perform ablation of CTI aimed at isolating only conductive tissue by combining impedance map with the Maximum Voltage Gradient (MVG) technique, in order to evaluate the efficacy of this strategy in acute and during follow-up.

Methods
From 01/2021 to 09/2023 impedance map and CTI substrate map was performed, without the use of fluoroscopy, in all patients undergoing ablation of typical atrial flutter. A 15-ohm impedance reduction from the mean atrial impedance was considered the cut-off for defining the presence of NCS. Substrate maps were constructed according to the MVG technique (0.5-2.5 mV thresholds), in particular looking for high-voltage channels in which the impedance map detected the presence of NCS. Ablation was performed only in the high-voltage channels (W45, AI500).

Results
Our study included 48 patients with a mean age of 68±13 years, with 92% of them being men. The mean volume of the right atrium was 153 mL, and the mean number of points per map was 1205. With the use of impedence map, we were able to identify the presence of NCS in 25 patients (52%). The distribution of non conductive structures and the mean voltage by quadrants can be seen in Figures B-C.
Importantly, we found that the mean number of radiofrequency applications required to achieve isthmic block was significantly lower in patients with identified NCS compared to those without (6.3 vs. 10; p=0.007). In 60% of the patients with NCS, radiofrequency was administered in high-voltage channels that were detected in the quadrant where the NCS was present (odds ratio 3.42, p=0.04). Furthermore, we successfully achieved acute isthmic blockade in all patients, and there were no instances of recurrence during a mean follow-up period of 186 days.

Conclusions
Our findings demonstrate that the combination of Impedence Map and the Maximum Voltage Gradient technique is an effective approach for achieving isthmic block with a reduced number of radiofrequency applications. The identification of NCS allows for a more precise search for high-voltage channels, enabling ablations to be performed in optimal contact with the tissue. This meticulous approach is crucial for the success of the procedure.
Feasibility of catheter ablation with zero-fluoroscopy in congenital heart disease
Authors: Mladoniczky S , Nagy Z , Frohlich R , Csakany L , Major T , Szegedi M , Som Z , Kardos A , Foldesi C , Balint O H , Kornyei L 
Published: May 2024

Abstract

Background
Catheter ablation (CA) with zero and near-zero fluoroscopy has been shown to be safe and effective in patients (pts) without structural heart disease, but there are limited data regarding CA in congenital heart disease (CHD).

Aim
Our aim was to compare the safety and outcome of zero-fluoroscopy (ZF) and fluoroscopy (non-ZF) CA of CHD pts.

Methods
This is a single-center retrospective study of CHD pts who underwent CA at our center between 2006-2020. The ZF and non-ZF groups were compared for the complexity of anatomy, arrhythmia substrate, difficulties of vascular access, transseptal or transbaffle puncture, intracardiac pacemaker/ICD, procedural parameters, complications, and acute outcome. Near-ZF CAs (effective dose ≤1 mSv) were assigned to the ZF group.

Results
The ZF group included 22 pts (age: 22±13 years) and the non-ZF group 48 pts (age: 31±12 years). The distribution of CHD anatomical complexity (mild/moderate/severe) was 18.2%-68.2%-13.6% in the ZF group and 14.6%-68.7%-16.7% in the non-ZF group. Arrhythmia diagnoses were focal atrial tachycardia (ZF: 4.6%), atrial flutter (ZF: 45.4%, non-ZF: 75.0%), atrioventricular reentry tachycardia (AVRT) via manifest accessory pathway (AP) (ZF: 31.8%, non-ZF: 10.4%), AVRT via concealed AP (ZF: 4.6%, non-ZF: 8.3%), and atrioventricular nodal reentry tachycardia (ZF: 13.6%, non-ZF: 6.3%). Difficulties in vascular access occurred in 4.5% of the ZF group and 18.8% of the non-ZF group (p=0.10). The rate of transseptal/transbaffle puncture was significantly higher in the non-ZF group (22.9% vs. 4.6%, p=0.04). In the ZF group 13.6% and in the non-ZF group 20.8% of pts had pacemaker or ICD (p=0.22). Electroanatomical mapping was used in all CAs in both groups. There was no significant difference in procedure time, ablation time and the number of radiofrequency applications (ZF group: 169±53 min, 1205±906 sec, 28±15 vs. non-ZF group: 203±74 min, 1459±940 sec, 34±16, p&gt;0.05). The acute success rate was 100% in both groups. No complications occurred in any group.

Conclusion
Zero fluoroscopic CA was feasible in 1/3 of the pts with CHD and as safe and effective as fluoroscopic ablation. No significant differences were found in the non-fluroscopy related procedural data between the two groups.
Role of high-density voltage map guiding parosysmal atrial fibrillation ablation
Authors: Rossi L , Biagi A , Bolognesi M G , Gibiino F , Aschieri D 
Published: May 2024

Abstract

Background
High-density mapping of the pulmonary vein antra has been demonstrated to improve the detection of conduction gaps in wide antral catheter ablation (WACA) approach for the treatment of paroxysmal atrial fibrillation (AF).

Purpose
We aimed to compare the AF recurrencies in patients treated with WACA for pulmonary veins isolation (PVI) guided by high-density bipolar voltage map (BVM) vs WACA guided by a standard 20-pole circumferential mapping catheter (CMC-20).

Methods
This prospective study included patients scheduled for AF ablation in a single center. In group A (85 patients) PVI was achieved with a conventional approach using CMC-20; in group B (96 patients) high density BVM was acquired by sequential multielectrode mapping through Pentaray Catheter (Biosense Webster). More than 1000 voltage points per map were acquired. Acute PVI was defined as an entrance and exit block after ≥ 20 min waiting period. In both groups WACA was perfomed using a contact force sensing catheter targeting an interlesion distance ≤6 mm and ablation index ≥400 at posterior wall and ≥550 at anterior wall. The primary endpoint was the AF recurrencies in the two groups.

Results
A total of 181 patients were included (mean age 64.9±10.6 years, 33.1% female): in 85 patients AF ablation was guided by CMC-20, in 96 patients AF ablation was guided by BVM; WACA PVI was achieved in all patients. There were no significant differences in the clinical characteristics of the two groups (table 1). At 12-month follow-up, AF recurrencies were significantly lower in the BVM group compared with CMC-20 group [11/96 (11.4%) vs 19/85 (22.3%) respectively, p=0.01].

Conclusions
High-density BVM might increase success rate of AF ablation compared with a conventional 20-pole circumferential mapping approach.