bluuebunny/crossref_metadata_2025_split huggingface dataset:
Outcomes of additional substrate modification in de novo atrial fibrillation ablation
Authors: Aslam F , Al-Sadawi M A , Aleem S , Ijaz H , Jacob R , Cao K , Santore L , Almasry I , Singh A , Fan R , Rashba E 
Published: October 2022

Abstract

Background
Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Data regarding additional substrate modification has been conflicting, both in paroxysmal and persistent atrial fibrillation.

Purpose
To assess the effect of additional linear substrate modification during de novo AF ablation on AF recurrence.

Methods
We reviewed 1575 AF ablations in 1254 patients from January 2013 to June 2021 at a single academic medical center. There were 1096 de novo ablations. We defined substrate modification as linear ablations including cavotricuspid isthmus (CTI), superior vena cava isolation, intercaval line, mitral isthmus, and left atrial roof and floor lines. We evaluated clinical and procedural characteristics to identify risk factors for AF recurrence and complications. Patients were followed for a minimum of 6 months.

Results
The 1096 de novo ablations included 65.5% males with mean age 61.1 years, mean BMI 31.3, 81.8% paroxysmal AF and 18.2% persistent AF. There were four AF ablation subgroups: PVI alone (41.6%), PVI and CTI ablation (37.1%), PVI with CTI and additional substrate modification (15.6%), and PVI with substrate modification without CTI ablation (5.7%). Overall, AF recurred in 36.9% cases. AF recurrence with PVI only ablation was 41% compared to 32.7% in patients with PVI and CTI ablation (p=0.02). When looking at patients with paroxysmal and persistent AF, results were similar, with decreased AF recurrence with the addition of CTI ablation in both paroxysmal (37.3% v. 29.2%, p=0.03) and persistent AF (58.1% v. 40.0%, p=0.02). Additional substrate modification did not result in significant difference in outcome in either paroxysmal or persistent AF (Figure 1).

Conclusions
In de novo AF ablations, addition of CTI ablation to de novo PVI ablation is associated with lower AF recurrence in both paroxysmal and persistent AF. Additional linear substrate modification did not impact outcomes.

Funding Acknowledgement
Type of funding sources: None.
Usefulness of the synthesized 18-lead ECG in identify the origin of premature ventricular contractions
Authors: Matsumoto H , Kida H , Nakanishi R , Miyoshi M 
Published: October 2022

Abstract

Background
There are have been reports on the 12-lead ECG waveforms used to identify ventricular premature contractions (VPCs), but there are not enough algorithms. On the other hand, the synthesized 18-lead ECG adds the right-side chest leads (V3R, V4R, and V5R) and back leads (V7, V8, and V9) to the 12-lead ECG.

Purpose
This aim of this study was to evaluate whether the waveforms of the 18-lead ECG are useful in predicting the origin of VPCs.

Methods
We studied 86 consecutive patients (age :61.8±16.0 years, male: 54.5%) enrolled from multicenter who underwent radiofrequency catheter ablation for VPCs. We retrospectively investigated the association between origin of the VPCs and characteristics of the synthetic 18-leads ECG.

Results
The 18-lead ECG showed a specific pattern for the VPC originating near the His-bundle. In 17 cases, the QRS morphology in V5R exhibited a QS pattern, and 13 of 17 cases had VPCs originating near the His-bundle. In the other 69 cases, V5R did not exhibit a QS pattern. ROC curve analysis showed that the QS pattern in V5R predicted VPC originating near the His-bundle with high accuracy: sensitivity 100.0%, specificity 94.5%, and AUC 0.98. Furthermore, the positive predictive value was 76.5% and negative predictive value 100.0%.

Conclusion
The QS pattern shown in V5R of the 18-lead ECG was a useful parameter for identifying VPCs originating near the His-bundle, which might be a good reference indicator during radiofrequency catheter ablation for VPCs.

Funding Acknowledgement
Type of funding sources: None.
Pulmonary vein isolation without fluoroscopy: results evaluation
Authors: Martinez Gomez E , Salgado Aranda R , Perez Castellano N , Serra B , La Rosa G , Chavez Ortiz I , Gonzalez Ferrer J J , Canadas Godoy V , Filgueiras Rama D , Jeronimo Baza A , Ferrandez Escarabajal M , Ramos Lopez N , Hennessey B , Perez-Villacastin Dominguez J 
Published: October 2022

Abstract

Introduction
From the outset, the use of Xray (XR) has been a critical component in both the guidance and development of arrhythmia ablation procedures. At present however, due to the complex nature of electrophysiology procedures, the use of XR in isolation is not sufficient to ensure procedural success. Subsequently, the use of non-fluoroscopic virtual mapping systems is essential. Currently, given the evolution of this technology and its essential nature for procedural guidance, it is worth asking whether the use of XR is indeed still necessary in the modern era. The objective of this study was to demonstrate that “zero-XR” ablation of complex arrhythmias such as atrial fibrillation is both possible and safe.

Methods
Between 2020 and 2021, a total of 116 patients admitted for pulmonary vein ablation were included in the study. Amongst these, 41 patients were prospectively included at our centre, in a protocol for point-by-point ablation of pulmonary veins without fluoroscopy, “zero-XR”. In addition to the non-fluoroscopic mapping system, the transseptal puncture was monitored by intracardiac ultrasound in all cases. The objective of the ablation was the complete isolation of the pulmonary veins. In some patients, at the discretion of the operator, the ablation of other substrates was added. For the remaining 75 patients in the study, the ablation was performed using conventional techniques without the limitation of the use of XR. The mean follow up was 12 months.

Results
The baseline characteristics of the patients, as well as the description of the procedure, are shown in the Table. There were no differences in the acute success rate or procedure time between the two groups. There was only one complication related to the procedure in the non-XR group consisting of pericardial effusion without cardiac tamponade. Regarding the recurrence rate at 12 months, it was higher in the group with fluoroscopy, without reaching statistical significance [n=0 in the group without fluoroscopy, n=2 (2.7%) in the group with fluoroscopy, p=0.15].

Conclusion
In our series, point-by-point ablation of atrial fibrillation without fluoroscopy proved to be a safe and feasible technique, with similar success rates when compared to conventional procedures using XR.

Funding Acknowledgement
Type of funding sources: None.
Initial experience with dielectric-based local tissue assessment for catheter ablation
Authors: Abeln B G S , Van Dijk V F , Balt J C , Wijffels M C E F , Boersma L V A 
Published: October 2022

Abstract

Background
Dielectric imaging systems can be used to guide catheter ablation for cardiac arrhythmia. Currently, the KODEX-EPD system can be used to acquire high-resolution anatomical data for electroanatomical mapping. Future software versions of this system enable tissue assessment utilizing local dielectric sensing. These dielectric-based tissue assessments (KODEX Vision) enable new features, including wall thickness measurement, catheter-tissue contact assessment, and ablation lesion assessment.

Purpose
To gain insight in the dielectric-based tissue assessment features.

Methods
The KODEX-EPD system was used to perform repeat ablations in patients with recurrent atrial fibrillation after pulmonary vein isolation. A primary system with the current software version (1.4.8) was used by the operator. Ablation was performed with a non-contact force-sensing irrigated radiofrequency catheter, with power set at 30–35W and aiming for ablation times of 30–60s. A secondary system was blinded for the operator and loaded with beta software (1.5.0) to enable the KODEX Vision features. Only successful local tissue assessments are presented in this abstract. All patients were enrolled in a prospective registry study which was approved by the local ethics committee.

Results
Electroanatomic mapping in 25 patients (age 65±8yr, male 84%, LAVI 31±9ml/m2) revealed electrical reconnection in 66 of 100 pulmonary veins. A total of 308 radiofrequency applications were used to re-isolate the veins and create additional lesions (superior vena cava isolation in 6, box lesion in 1). Wall thickness at the sites of ablation ranged from 1.3–3.9 mm. Tissue contact assessment at the start of RF applications indicated “touch” in 77%, while 17.5% and 5.5% of results indicated `no touch' or “high touch”. Tissue Response Viewer indicated low dielectric response in 18.5% and high dielectric response in 81.5% of results. High dielectric response was associated with lower wall thickness (OR: 0.86, 95% CI [0.76–0.97], p=0.014).

Conclusion
This preliminary evaluation underlines the potential of dielectric-based tissue assessment features. Wall thickness measurement, catheter-tissue contact, and ablation lesion assessment seem feasible with the beta software. Further evaluation of the feasibility, accuracy and clinical impact of the finalized software is warranted.

Funding Acknowledgement
Type of funding sources: None.
Clinical outcomes of high-density mapping for atypical atrial flutter ablation
Authors: Abeln B G S , Balt J C , Klaver M N , Maarse M , Van Dijk V F , Wijffels M C E F , Boersma L V A 
Published: October 2022

Abstract

Background
High-density mapping is increasingly used in catheter ablation of complex arrhythmias. In atypical atrial flutters (AAFl), high-density mapping can provide a more accurate delineation of the arrhythmic circuit. This promotes acute procedural success, but follow-up data on clinical outcomes are scarce.

Purpose
To study procedural characteristics and arrhythmia recurrence of high-density mapping-guided AAFl ablation.

Methods
In this monocenter prospective observational cohort study, we included patients that were treated for AAFl using a high-density mapping system with a grid-patterned mapping catheter. We evaluated acute procedural success and atrial flutter recurrence at follow-up. Acute success was defined as non-inducibility of atrial flutters. Arrhythmia recurrence was defined by electrocardiographic documentation of atrial flutter.

Results
Between April 2018 and July 2020, 65 patients (69% male; age 65±8yr; 69% prior PVI; 60% prior cardiac surgery) were included in this study. A total of 100 AAFl were observed during the procedures. The flutter circuit was unmappable for 14 flutters in 11 patients (17%). Critical isthmuses were identified and ablated in 32 patients (49%). Other ablation strategies included linear ablation lesions (i.e., roof in 25% of patients, box in 9%, anterior in 35%, left lateral mitral in 17%), re-PVI (11%), septal (8%) and right atrial (8%) ablation. Acute procedural success was achieved in 86% of the cohort. During a follow up of 1.5±0.7 years, 38% of the cohort had recurrence of an atypical atrial flutter for which 23% had a re-intervention (repeat flutter ablation in 11% patients and his ablation with pacemaker implantation in 14%). Atypical atrial flutter recurrence was associated with presence of an unmappable flutter (HR: 2.7, 95% CI [1.1–6.4], p=0.03) and critical isthmus ablation (HR: 0.40, 95% CI [0.17–0.93], p=0.03).

Conclusions
Despite high-density mapping, 38% of patients had recurrence of an AAFl at follow-up. Presence of an unmappable flutter was associated with atrial flutter recurrence while critical isthmus ablation was associated with freedom from atrial flutter recurrence.

Funding Acknowledgement
Type of funding sources: None.
Safety and efficacy of catheter ablation for atrial fibrillation in the very elderly
Authors: Wahedi R , Willems S , Jularic M , Hartmann J , Schaeffer B , Akbulak-Stegli Ö , Eickholt C , Anwar O , Maurer T , Hedenus K , Gunawardene M 
Published: October 2022

Abstract

Background
The incidence and prevalence of atrial fibrillation (AF) increases with age. With an ageing general population, a 2.3-fold rise in AF prevalence is expected. Catheter ablation has emerged as an effective treatment option for rhythm control therapy. However, very elderly patients (≥80 years old) have been excluded in landmark clinical trials. Current data regarding the safety and efficacy of catheter ablation in the very elderly is therefore sparse.

Purpose
Due to the growing demand to manage AF in an increasingly ageing population, we investigated the safety and efficacy of catheter ablation in this particular patient population.

Methods
Patients with symptomatic paroxysmal, persistent and long-standing persistent AF aged ≥80 years undergoing catheter ablation, including first and re-ablation procedures in a single centre, were analysed retrospectively. Catheter ablation involved pulmonary vein isolation (PVI) using radiofrequency, cryoballoon and pulsed field ablation as energy sources. Re-ablation procedures included re-PVI and consecutive atrial tachycardia ablation including atrial lines and/or ablation of complex fractionated atrial electrograms (CFAE) in persistent AF. Endpoints included acute procedural success (complete isolation of pulmonary veins and/or non-inducibility in the case of atrial tachycardia), major complications and early arrhythmia-recurrence.

Results
A total of eighty-eight patients (mean age 83.1±1.9 years, mean CHA2DS2-VASc-Score 4.4±1, mean left ventricular ejection fraction 56.7±7%, direct oral anticoagulation 92.1%, vitamin-K antagonists 7.9%) were included from January 2021 to October 2021. Fifty cases (56.8%) involved PVI as an index procedure (radiofrequency 58%, n=29/50, cryoballoon 36%, n=18/50, pulsed field ablation 6%, n=3/50). Thirty-eight procedures (43.2%) involved re-ablation procedures (Re-PVI 60.5%, n=23/38, linear lesions 65.8%, n=25/38, atrial tachycardia ablation 26.3%, n=10/38 and ablation of CFAE 15.8%, n=6/38). Acute procedural success was achieved in 87/88 patients (98.9%). Major complications included stroke (n=1/88, 1.1%), pericardial tamponade (n=1/88, 1.1%) and bradycardia with subsequent pacemaker implantation (n=3/88, 3.4%). No further major complications were documented. In 13/88 patients (14.8%) early arrhythmia-recurrence occurred (38.5%, n=5/13 after the index procedure and 61.5%, n=8/13 after re-ablation) during the 90-day blanking period.

Conclusions
Catheter ablation for atrial fibrillation in the very elderly shows favourable acute success and low complication rates. Long term success of catheter ablation and superiority to rate control in this patient population is unknown and requires investigation in the future.

Funding Acknowledgement
Type of funding sources: None.
Safety and effectiveness of very high-power short duration ablation in patients with atrial fibrillation: early results
Authors: Mitrzak K , Krzowski B , Peller M , Maciejewski C , Marchel M , Balsam P , Grabowski M , Lodzinski P 
Published: October 2022

Abstract

Background
Pulmonary vein isolation (PVI) is at the forefront of treatment methods of rhythm control in patients with atrial fibrillation (AF) (1). The novel contact-force sensing catheter, QDot MicroTM (Biosense Webster) was designed to improve effectiveness of AF ablation and allow better time management due to shorter procedure time. It is a very high power-short duration (vHP-SD) catheter optimized for high density mapping and temperature control, which enables the application of high energy (up to 90W, 4s) (2).

Purpose
The aim of the study was to compare the QDot MicroTM catheter with the ThermoCool SmarttouchTM SF catheter with regard to the effectiveness and safety of PVI ablation.

Methods
It is a single center, cross-sectional, observational study enrolling 101 consecutive patients suffering from symptomatic paroxysmal or persistent AF, referred for first catheter ablation between 16 December 2019 and 03 December 2021. In 47 procedures (mean age 54 years; 70% male; 77% paroxysmal) the QDot Micro catheter was used (vHP-SD group; Qmode+ 90W, 4s), whereas the remaining 54 patients (mean age 57 years; 70% male; 67% paroxysmal) were treated with the ThermoCool SmarttouchTM SF catheter (control group, Ablation Index guided ablation). The primary endpoint was freedom from AF at 3-months after ablation. The secondary endpoints included the amount of opioids administered as well as the incidence of early-onset treatment-emergent adverse events (TEAEs).

Results
AF recurrence was documented in 14.9% patients in vHP-SD group and in 31.5% patients in control group (p=0.06). The mean dose of remifentanil was reported to be lower during Qmode+ catheter-based PVI (0.50 (0.40–0.60) vs. 0.70 (0.55–0.90) mg; p&lt;0.001). There was no statistically significant difference in TEAEs between both groups (6.3 vs. 0%; p=0.10). One severe adverse event (cerebral vascular incident 2 days after PVI – due to thrombus in the left ventricle) was observed in vHP-SD group.

Conclusions
This study suggests that the vHP-SD ablation is safe and enables sedative-analgesic medications demand reduction during procedure. vHP-SD mode may enhance the success rate of catheter-based PVI, however further research is needed to provide additional evidence of its superiority.

Funding Acknowledgement
Type of funding sources: None.
An analysis of the influence of atrial wall thickness on the protective effects of proactive esophageal cooling during high-power short-duration radiofrequency ablation
Authors: Mercado Montoya M , Gomez Bustamante T , Berjano E , Hernandez Arango P , Mickelsen S , Schieber J , Kulstad E , Daniels J 
Published: October 2022

Abstract

Background
The use of proactive esophageal cooling using a dedicated cooling device during radiofrequency (RF) left atrial ablation has increased, with endoscopic studies showing reductions in esophageal lesions using medium power ablation settings. With no atrioesophageal fistula yet identified using esophageal cooling, and clinical practice increasingly shifting to high-power short-duration (HPSD) ablation, additional data on the protective potential of this technique in HPSD ablation may help guide RF ablation strategies. In particular, a better understanding of the effects of anatomical variations in myocardial thickness on cooling efficacy is warranted.

Purpose
We sought to evaluate the influence of atrial wall thickness on the protective effects of proactive esophageal cooling during HPSD ablation.

Methods
Using a computer model of the left atrium and esophagus, we analyzed the esophageal damage that occurs under two HPSD ablation conditions (50 W for 10 s and 90 W for 4 s) with and without proactive esophageal cooling while varying atrial wall thickness. Injury to the esophagus was quantified using the Arrhenius equation as well as by determining the percentage of tissue reaching a 50°C lethal isotherm. Atrial thickness was varied between 0.6 mm to 2.0 mm. Esophageal cooling was set to the recommended 4°C coolant temperature.

Results
Using 50 W power settings in control (non-cooled) conditions, esophageal lesion transmurality ranged from 75% to 82% as calculated by the Arrhenius equation, with decreased transmurality seen as atrial wall thickness increased. With the addition of proactive cooling, lesion transmurality decreased to less than 43% in the thinnest atrial wall sections, and to less than 25% in the thickest atrial wall sections. Using 90 W power settings, control conditions showed esophageal lesion transmurality ranging from 52% to 63%, with the greatest damage seen in the middle-range atrial thicknesses (1 and 1.5 mm). Active esophageal cooling reduced this esophageal injury to less than 12% transmurality through the esophagus in all anatomic scenarios.

Conclusions
Modeling suggests that the use of proactive esophageal cooling significantly reduces esophageal lesion transmurality under HPSD ablation conditions across a range of typical atrial wall thicknesses, including in very thin myocardium, where the risk of esophageal injury is greatest.

Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Attune
Atrio-ventricular nodal re-entrant tachycardia ablation step by step low fluoro approach to prevent unexpected AV block
Authors: Marchese P , Gennaro F , Mazzotta G , Grossi P 
Published: October 2022

Abstract

Background
Slow pathway (SP) radiofrequency (RF) ablation of AVNRT has a success rate of more than 98%, but up to 2% risk of unpredictable and frustrating AV node block despite the energy being delivered to the posterior aspect of Koch's Triangle (KT) which is far from the recorded His signal. A possible explanation is an atypical location of the AV node. KT pace-mapping (KTPM) has been demonstrated to be useful to recognize when AV is abnormally located in the mid or posteroseptal aspect of the KT. In these cases cryoablation would be the best choice because it is a well-established technique for the successful treatment of AVNRT with no complications reported but with a recurrence rate around 10% at long-term follow-up. Voltage bridge mapping (VBM) is a validated and effective technique in guiding cryoablation of AVNRT, with a complete acute success rate and no recurrences at mid-term follow-up.

Aim
To evaluate our low-fluoro step-by-step approach for AVNRT ablation including KTPM and VBM aiming to eliminate the risk of unpredictable AV node block.

Methods
The right atrium and coronary sinus electroanatomical mapping was done and diagnostic catheters were positioned at His and coronary sinus. After AVNRT diagnosis, 3D KTPM was performed. We developed it according to the “conventional” one in order to evaluate and visualize atypical AV node location during low-fluoro procedures. This was achieved by stimulating with the mapping catheter in the anteroseptal, posteroseptal and midseptal region respectively. Each point has been collected on 3D System measuring the interval between the stimulus to the His deflection (Fig. 1A–C). Voltage bridge-mapping was also performed, and both have been used as reference for SP RF ablation. If 3D KTPM showed a posterior extension of the AV node, then ablation was performed using cryo-energy aiming to reduce the risk of permanent AV node iatrogenic block.

Methods and results
71 consecutive patients (mean age 61.0±14.5 SD, 46% female) undergoing low-fluoro ablation of AVNRT by 3D mapping system. KTPM was achieved in all the patients. In the 67 (94.3%) pts who showed superoparaseptal location of the AV node RF ablation was successfully performed. In 4 (5.7%) pts with midseptal extension of the AV node (Fig. 1D) a voltage-bridge mapping guided cryo-ablation was successfully performed (Fig. 1E). The mean procedural time was 95±18 SD min. Mean fluoro time was zero. After a mean follow-up of 28.5±16.7 SD moths, neither recurrences nor complications were recorded.

Conclusion
This is the first study to show how a tailored low-fluoro AVNRT SP ablation approach including 3D-PM of KT and VBM could be helpful to eliminate the risk of unpredictable and frustrating AV block. Our preliminary results would possibly encourage larger cohort, multicenter studies.

Funding Acknowledgement
Type of funding sources: None.