bluuebunny/crossref_metadata_2025_split huggingface dataset:
Patient-tailored low-voltage-guided ablation of atrial fibrillation: initial experience using a novel ultra-low-temperature cryoablation system
Authors: Raffa S , Frommhold M , Borisov G , Keelani A , Abdelwahab H , Alothman O , Geller J C 
Published: May 2024

Abstract

Introduction
The ideal ablation strategy for patients (pts) with persistent atrial fibrillation (PersAF) is still debated. In recent randomized studies, strategies of ablating electrically abnormal atrial regions in addition to pulmonary vein isolation (PVI) have shown promise, and a novel ultra-low-temperature cryoablation (ULTC) system might overcome the limitations of radiofrequency (RF) energy to create transmural lesions in diseased tissue.

Purpose
Aim of this study is to report procedural aspects, acute efficacy, and safety of our initial experience in treating AF pts with this novel ULTC system.

Methods
Patients scheduled for catheter ablation who had a high likelihood of having left atrial (LA) low voltage zones (LVZ) underwent ablation with the ULTC system. A detailed high-density LA 3D-electronatomical map was created in sinus rhythm using a multi-electrode catheter. Bipolar LVZs were defined as at least 1cm2 surface of bipolar voltage &lt;0.5mV. The ablation strategy consisted of PVI and linear ablation of the LVZs, transecting (if narrow) or isolating (if broad) the areas of abnormal signals and anchoring these lines to electrically silent structures (PVs or mitral valve ring). Electrical isolation and block across linear ablations were tested as universally accepted. Continuous variables are expressed as median (and interquartile ranges).

Results
From April to September 2023, 25 pts (10 female) were included (see table for patients´ and procedural characteristics). Procedure duration was 210 (135-270) min, and diminished over time from initially (in the first 12 pts) 260 (203.75-302.50) min to 190 (135-235) min (p=0.047). PVI was achieved in 15/18 pts (83%) using the ULTC, in the remaining 3 pts RF energy touch-up was needed. Linear ablation and isolation of LVZs were always (41/41 in 22pts, 100%) successfully achieved with the ULTC (see figure for an example). Except for 1 right phrenic nerve palsy, no major acute complications were observed. Post-procedural chest pain was not reported by any patient, in 1 patient mild pericardial effusion was detected and treated conservatively. During the 48h post-procedural ECG-monitoring, no sustained atrial arrhythmias occurred.

Conclusions
This is the first report of patient-tailored low-voltage-guided AF-ablation using a novel ULTC system. Despite representing our initial clinical experience, acute efficacy was very good (95% of acute bidirectional block across lines). Procedure-duration decreased over time, indicating an initial learning curve. Acute safety was reassuring but particular attention should be paid for phrenic nerve function during ablation of the right PVs. The absence of post-procedural pain, pericardial effusion, or acute post-procedural arrhythmias indicates limited ablation-induced inflammation.Result of ULTC ablation in a diseased LA
Changes in local endocardial electrograms immediately after PFA show dose-dependent variations
Authors: Amoros-Figueras G , Zoraida Moreno-Weidmann Z , Sergi Casabella-Ramon S , Ivorra A , Guerra J , Garcia-Sanchez T 
Published: May 2024

Abstract

Background/Introduction
Pulsed field ablation (PFA) is a novel nonthermal cardiac ablation technology based on irreversible electroporation. The behaviour of local electrograms after PFA has been poorly characterized and it remains unknown if it is possible to differentiate between different electroporation levels based on local electrogram analysis.

Purpose
The objective of this study was to characterize the alterations in bipolar and unipolar endocardial electrograms after performing PFA at different doses.

Methods
Five anesthetized pigs were submitted to PFA treatments. Endovascular access to the right atrium was gained through the femoral vein to create a line of ablation between the superior and inferior vena cava using a focal monopolar catheter. The catheter was switched between a conventional cardiac navigation system (CARTO system) and a custom PFA generator. Two different PFA doses were used: a high dose (HD-1600V) at top and bottom of the line and a low dose (LD-1000V) in the central part of the ablation line. Bipolar and unipolar electrograms were recorded with the ablation catheter before and immediately after each ablation. Additionally, high-density electroanatomical maps were acquired with a multielectrode catheter before and immediately after the procedures. Four weeks later, the animals were remapped again and subsequently euthanized. Atrial tissue was removed and processed to identify the presence of fibrosis in the previously ablated lesions.

Results
We performed 106 ablations (84 high dose vs. 22 low dose). Four weeks later, histological staining of chronic lesions revealed that the HD lesions were larger and more fibrotic than the LD (Figure 1). Immediately after each ablation R/S-wave amplitudes and their corresponding |dV/dt|max decreased for the bipolar and unipolar electrograms. The percentages of bipolar electrogram reduction HD vs. LD were: R wave 73% vs. 39%, S wave 68% vs. 37% and |dV/dt|max 81% vs. 38%; 1 way-ANOVA p&lt;0.05 for all, Figure 2). The R-wave amplitude in M1-M2 was significantly lower in HD compared to LD (HD vs. LD: 0.3 ± 0.2 mV vs. 0.7 ± 0.6 mV; 1 way-ANOVA p&lt;0.01). S-wave and |dV/dt|max of unipolar electrograms presented a similar behaviour (M2 |dV/dt|max HD vs. LD: -116 ± 118 mV/s vs. -260 ± 267 mV; 1 way-ANOVA p&lt;0.01).

Conclusion
Local electrograms display PFA dose-dependent variations. This information could result useful to create new metrics to assess in real time the performance of PFA systems.Figure 1.EAM maps and histology studyFigure 2.EGM signals and statistics
Examination of pituitary adenylate cyclase-activating polypeptide (PACAP) in patients with atrial fibrillation undergoing pulmonary vein isolation
Authors: Toller K , Tamas A , Polgar B , Janosi K , Toth T , Debreceni D , Reglodi D , Kupo P 
Published: May 2024

Abstract

Introduction
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a cardioprotective neuropeptide. It has previously been shown that plazma PACAP level increases in myocardial infarction and decompensated heart failure, whereas it decreases in chronic heart failure.

Patient material and method
We examined blood samples from patients (n=46) undergoing pulmonary vein isolation for atrial fibrillation. We collected 5 ml blood samples from the femoral vein at the beginning, from the right atrium before the septal puncture, from the left atrium before and after the ablation, from the femoral vein at the end of the procedure and the next day from the cubital vein. PACAP levels were determined by ELISA. Patients were divided into intact (n=29) and scarred (n=17) left atrial groups by electroanatomical map. PACAP levels were compared in the total population and in the two groups and correlated with left atrial size and different comorbidity data.

Results
Significantly higher levels of PACAP were detected in atrial blood and in post-operative femoral vein samples compared to peripheral blood collected at the beginning and 1 day after the procedure. We measured decreased PACAP levels in the left atrium after ablation compared to samples from left atrium before the ablation. Although we found lower PACAP levels in the left atrium after ablation in patients with scarred atrium compared to the intact group, the PACAP levels showed significant elevation in the femoral vein after the ablation in patients with intact atria.

Conclusions
Our study was the first to show a difference between PACAP levels in atrial and peripheral blood samples. The elevated PACAP levels measured in atrial samples may be due to myocytes and neurons, whose PACAP production decreases depending on the degree of scarring following ablation-induced injury in the left atrium. Transient systemic elevation of PACAP levels is demonstrated in the periphery, suggesting a potential biomarker role for PACAP in these pathologies.
Real-time characterization of radiofrequency lesions by local multifrequency impedance with thermal correction
Authors: Amoros-Figueras G , Casabella-Ramon S C R , Moreno-Weidmann Z M W , Rosell-Ferrer J R F , Guerra J G 
Published: May 2024

Abstract

Background/Introduction
Recent studies have shown that measuring local impedance (LI) at a single frequency can be useful for real-time characterization of radiofrequency (RF) lesion size during arrhythmia ablation procedures. (1) However, these systems do not take into account the effect of the increase in tissue temperature on the impedance measurement itself, which could be avoided by comparing the impedance at different frequencies.

Purpose
The aim of this study was to evaluate the ability of local multifrequency impedance (LMI) to characterize the size of RF lesions in real-time, while correcting for the thermal effect on the measurement.

Methods
Lesions were performed on the epicardium in 5 anesthetized pigs while measuring IML (from 1 to 209 kHz) before, during, and after ablations (20W/30W/40W, 60s, &gt;10g) through a conventional irrigated electrocatheter connected to a cardiac navigation system and a RF generator. In these measurements, the thermal effect on the tissue was corrected by assuming that the changes in impedance at high frequency were only due to the temperature variation and not to the injury itself. Local voltage (Vuni) was also measured before and after ablations, and catheter-measured temperature and contact force were monitored. At the end of the procedure, the animals were sacrificed, and a histological study of the lesions was performed.

Results
A total of 43 effective lesions (11±2 per animal) were performed. The 40W lesions were deeper and wider than the 20W lesions (6,6 ± 3,3 mm vs. 5,4 ± 2,0 mm vs. 4,0 ± 1,9 mm; ANOVA p&lt;0.05) and presented a significant decrease in unipolar voltage that was similar among the different lesions (40W vs. 20W: 56% vs. 40%; ANOVA p=ns; Figure). Four seconds after the start of the ablation the 40W lesions had a greater decrease in IML than the 30W and 20W lesions (73±14Ω vs. 85±4Ω vs. 100±12Ω; ANOVA p&lt;0.05). After thermal adjustment, IML recorded 30 and 55 seconds after the start of the ablation correlated better with the final depth of the lesion than IL or Vuni (Table).

Conclusions
The measure of IML during ablation allows a better quantification of the changes in the structural characteristics of myocardial tissue than local impedance at a single frequency. The increase in tissue temperature during ablation influences the values of local impedance and should be considered when creating new impedance-based metrics to predict the chronic size of the RF lesion.Figure.Lesion quantification by LMITable.Correlation analysis
Acute and one-year procedural effects with proactive esophageal cooling during radiofrequency ablation with proactive esophageal cooling - comparison of paroxysmal and persistent atrial fibrillation
Authors: Sherman J , Ro A , Nazari J , Fisher W , Kulstad E , Metzl M 
Published: May 2024

Abstract

Background/Introduction
Proactive esophageal cooling is FDA cleared to reduce the likelihood of ablation-related esophageal injury from radiofrequency (RF) cardiac ablation, and is becoming more prevalent as an alternative to luminal esophageal temperature (LET) monitoring. Data also suggest shorter procedure times and improved freedom from arrhythmia with esophageal cooling due to the lower continuity index achieved with esophageal cooling.

Purpose
To determine acute and long-term procedural outcomes of PVI for paroxysmal and persistent atrial fibrillation (AF) using active esophageal cooling.

Methods
Procedure times and one-year follow-up rhythm status of all patients treated with PVI for paroxysmal and persistent AF by a single operator were reviewed. Patients were treated over the time span February 2020 through July 2022. Procedure times and freedom from atrial arrhythmia were then compared between paroxysmal and persistent AF.

Results
A total of 317 patients with paroxysmal or persistent atrial fibrillation were treated over the course of the study timeframe. Of these patients, 167 (52.7%) had paroxysmal atrial fibrillation, and 150 had persistent AF. Mean age was 70.6±11.0 years (paroxysmal AF: 68.2±10.4 years and 43% female, persistent AF: 73.4±11.0 years and 37% female), with 40% female overall. Mean procedure time was 68.8±28.1 minutes (61.4 minutes for paroxysmal, 77.3 minutes for persistent). Most patients (224, or 71%) received no fluoroscopy, while the remainder received 1.28±4.0 minutes of fluoroscopy use. The KM estimate for freedom from atrial arrhythmia at one-year for paroxysmal patients was 81.4±3.9%. For persistent patients, the KM estimate for freedom from atrial arrhythmia at one-year was 70.4±4.4% (Figure 1).

Conclusions
Proactive esophageal cooling is associated with a high rate of long-term freedom from arrhythmia for both paroxysmal and persistent AF patients, as well as short procedure times, and the ability to achieve low or zero fluoroscopy use.Figure 1
Posterior wall isolation in patients with persistent atrial fibrillation: a single center comparative study between ablation index and very high power short duration radiofrequency ablation protocol
Authors: Ciconte G , Negro G , Boccellino A , Rondine R , Maiolo V , Sabatelli L , Ballarotto M , Salerno R , Napolano A , Giannelli L , Calovic Z , Vicedomini G , Pappone C 
Published: May 2024

Abstract

Background
Circumferential pulmonary veins ablation (CPVA) with posterior wall isolation (PWI) using radiofrequency catheter ablation (RFCA) is gaining increasing interest in terms of safety and efficacy.
Purpose To compare procedural data and efficacy between two radiofrequency ablation protocols for the treatment of persistent atrial fibrillation (PersAF): very high power-short duration (vHPSD) ablation using a novel temperature-controlled ablation catheter and Ablation Index (AI) guided RFCA using traditional contact-force catheter.

Methods
This single center prospective study enrolled 75 consecutive patients (Group 1) with symptomatic PersAF undergoing RFCA using a novel contact-force catheter optimized for temperature-controlled ablation with microelectrodes and 6 thermocouples for real-time temperature monitoring during ablation. The vHPSD algorithm modulates power to maintain target temperature during these lesions (90 Watts, 4 s) in the posterior wall. RF delivery in anterior regions was performed in a temperature guided setting (1-45W, 45°C) to achieve a 500-550 AI. These patients were compared to 75 propensity matched patients (Group 2) undergoing PersAF ablation with traditional AI-guided ablation. Procedural data were compared between the two groups (Table 1). Procedural outcome was considered as loop recorder documented atrial arrhythmias recurrences and compared between the two groups.

Results
Seventy-five patients (69% male, 63.1±11.2 years old) underwent ablation with vHPSD protocol (Group 1). CPVA and PWI was achieved in all patients with total procedure and fluoroscopy times of 67.5±28.8 min and 4.5±2.8 min, respectively. After 12-month median follow-up, 57/75 patients (76%) were free from AF. Seventy-five propensity matched patients (69% male, 60.7±9.9 years old) have undergone ablation with standard contact-force catheter. CPVA and PWI was achieved in all patients with total procedure and fluoroscopy times of 81.99±20.5 min and 5.7±2.1 min, respectively. After 12-month median follow-up, 55/75 patients (73%) were free from AF. Procedural and fluoroscopy times were significantly lower in in Group 1 than in Group 2 (Table 1). AF recurrencies were comparable between the two groups as assessed with survival analysis (Figure 1, log-rank 0.509). There were no deaths or other severe periprocedural complications.

Conclusions
PWI on top of CPVA is effective in limiting arrhythmic recurrences following RFCA of PersAF. Compared to standard AI guided ablation, vHPSD protocol significantly reduces procedural time and fluoroscopy exposure. Clinical outcomes between the two protocols are similar.Figure 1
Impact of catheter ablation on erectile dysfunction in atrial fibrillation patients
Authors: La Fazia V , Pierucci N , Gianni C , Torlapati P G , Mohanty S , Della Rocca D G , Massaro G , Bode W , Bassiouny M , Burkhardt J D , Horton R , Al-Ahmad A , Sangiorgi G M , Di Biase L , Natale A 
Published: May 2024

Abstract

Background
Previous studies suggested a consequential link between impaired diastolic function, which could be related to atrial fibrillation (AF), and a heightened susceptibility to erectile dysfunction (ED). No data exists regarding the correlation between restoration of sinus rhythm and ED.

Objective
This study investigates the influence of cardiac ablation on the need for phosphodiesterase-5 inhibitors (PDEF5i) medications in patients with atrial fibrillation.

Methods
We retrospectively investigated by chart review 220 consecutive male patients with erectile dysfunction who underwent AF catheter ablation and performed at least one follow-up visit afterward between 2019 and 2022. Exclusion criteria were considered patients older than 85 years old and those assuming non-selective beta-blockers or antidepressant medications. Patients were monitored for arrhythmia at quarterly office visits, ECGs, 7-day Holter monitoring, and event recorders during the first year. The Chi-Square test was utilized to statistically analyze the correlation between the achievement of sinus rhythm post-ablation and the discontinuation of ED medications.

Results
During follow-up 182 (82.7%) pts remained in sinus rhythm after one year (Group 1). Among these, 141 (77.4%) reported withdrawal of ED medication and a marked improvement in their overall sexual health and satisfaction. Whereas among the 38 (17.3%) who did not maintain stable sinus rhythm during follow-up (Group 2), only 2 (5.2%) reported a reduction in ED medication. A statistically significant difference was observed when comparing the two groups (p&lt;0.001, OR 0,016, 95%, 0,003 - 0,061). Moreover, patients maintaining sinus rhythm for more than six months exhibited a higher tendency to stop ED medications compared to those with shorter periods of sinus rhythm or with recurrent AF episodes.

Conclusion
Our findings suggest a strong association between the achievement of sinus rhythm through cardiac ablation and a reduction PDEF5i in patients affected by ED medications in AF patients. This highlights the potential dual benefits of cardiac ablation in improving quality of life and in improving sexual health.
Temporal stability of local cycle length and duty cycle distribution during atrial fibrillation
Authors: Schmidt K , Unger L A , Haas A , Vacanti G , Widder J , Luik A 
Published: May 2024

Abstract
Appropriate targets for catheter ablation of atrial fibrillation (AFib) beyond pulmonary vein isolation (PVI) are still controversially discussed. Since available parameters to analyze the vulnerable substrate are very limited, there is the need to define and understand tailored features. Mapping during AFib can be particularly challenging due to its non-repetitive nature. Amongst others, temporal stability despite changing activation sequences is an essential requirement for features applied to AFib maps. The local cycle length (CL) and duty cycle (DC) offer novel measures to characterize the atrial substrate during AFib.
This study aims at providing first insights into the temporal stability of CL and DC during AFib in order to assess the suitability of both features for the characterization of the individual substrate and tailor ablation strategies in future.
In patients with recurrent AFib after PVI, two high-resolution 3D electro-anatomical maps were recorded sequentially during AFib before any ablation. Intracardiac electrograms (EGMs) were preprocessed to improve local signal quality and far field suppression. EGMs were recorded with a multipolar, basket-shaped high-density mapping catheter. Local CL and DC distribution were visualized using scatter plots and histograms. CL quantifies the time between subsequent local activations, DC quantifies the fraction of CL with local EGM activity, and the confidence (conf) feature quantifies the spatiotemporal consistency of EGM morphology. Only recordings with conf &gt; 0.6 are analyzed. Feature calculation is based on a weighted conglomerate of all acquisitions within a series of beats. Adjustable CL and DC thresholds allow highlighting regions within the 3D map for individual spatial analysis. Both the global distributions and the local occurrence of CL and DC were compared in order to assess temporal stability.
Four patients (2x paroxysmal AFib, 2x persistent AFib) were enrolled. All subjects underwent repeat ablation after PVI due to recurrence of AFib. Table 1 summarizes mapping parameters for both AFib maps in individual patients. Despite differences in mapping time and the number of EGMs, CL and DC histograms were significantly similar when comparing maps within one patient. For individually selected ranges of CL and DC in the upper left corner of the scatter plot (short CL and high DC), localization of corresponding areas was comparable in both 3D maps. An example is shown for patient I in the left and central column of the figure.
CL and DC distributions were temporally stable features for all patients in this study cohort. Localization of EGMs of given CL and DC range within the 3D maps were comparable but not identical for arbitrarily selected ranges. CL and DC can therefore be considered valid features for substrate characterization during AFib. Further studies will need to investigate how ablation strategies can be derived from individual CL and DC distributions.