Catheter Ablation Technology Research Articles

Atrial Fibrillation in Heart Failure: Strategies for Restoring Sinus Rhythm

Atrial fibrillation (AF) and heart failure (HF) are epidemics that deserve greater attention in the current era. With improved medical therapies and robust revascularization strategies for acute coronary syndromes, there has been a substantial increase in the population of people living with stable coronary artery disease, which in turn contributes to the AF and HF burden. AF and HF are unique disease processes, in that each can precipitate the other, and in those with co-existing AF and HF, the burden of morbidity and mortality is amplified. While there has been remarkable progress in the sphere of pharmacological therapy for HF (particularly HF with reduced ejection fraction), medical therapy options for rate and rhythm control for AF have been largely unchanged for several decades. Instead, advances in catheter ablation (CA) technology and strategies for AF ablation have culminated in a robust evidence base, showing improved survival, quality of life, and restoration of ventricular function. The purpose of this clinical review article is to summarize the pathophysiological link between AF and HF and to emphasize the role of CA in the management of such patients.

Pulsed field ablation in patients with cardiac implantable electronic devices: an ex vivo assessment of safety.

Pulse field ablation (PFA) is a novel catheter ablation technology with potential safety benefits due to its tissue selectivity. It has the potential to directly damage or interact with the functionality of cardiac implantable electronic devices (CIEDs) in the form of electromagnetic interference (EMI). The aim of our study was to assess the impact of PFA on CIEDs. PFA lesions (45 per CIED) were applied from the Farapulse system to CIEDs (< 5 cm from the lead tip and < 15 cm from the generator). All devices were checked before and after PFA application for proper sensing and pacing functionality as well as for integrity of shock circuits in ICDs using a heart simulator. Moreover, devices were then interrogated for any spontaneous reprogramming, mode switching or other EMI effects. In total, 44 CIEDs were tested (16 pacemaker, 21 ICDs, 7 CRT-P/D) with 1980 PFA applications. There was no change in device settings, functionality and electrical parameters, and there was no macroscopic damage to the devices. The risk of damage to the electric components or leads on a patient-based analysis is 0/44 (95% CI 0-8%) and on a PFA pulse-based analysis is 0/1980 (95% CI 0-0.2%). Clinically relevant EMI appeared with oversensing and pacing inhibition but not tachycardia detection. Bipolar PFA appears safe and does not result in damage to CIEDs or leads. Clinically relevant EMI does occur, but appropriate peri-procedural programming may mitigate this. In vivo studies are needed to confirm our findings.

Comparative Safety of Pulsed Field Ablation and Cryoballoon Ablation Technologies for Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation: A Critical Literature Review and Indirect Treatment Comparison.

Cryoballoon ablation (CBA) is a standard catheter ablation technology with demonstrated clinical effectiveness for the treatment of paroxysmal atrial fibrillation (PAF); however, it can be associated with major adverse events, including phrenic nerve paralysis. Pulsed field ablation (PFA) is a novel, minimally thermal technology with comparable effectiveness and low safety risk. This study aimed to compare the safety profiles of PFA and CBA through critical analyses of the literature and indirect treatment comparisons. Studies were identified by searching the MEDLINE database and the Clinicaltrials.gov registry. Registered clinical trials and/or Food and Drug Administration Investigation Device Exemption (FDA IDE) studies evaluating PFA or CBA in adult patients with drug-refractory PAF between January 2008 and March 2023 were selected. Comparative safety between PFA and CBA was assessed for major and prespecified adverse events. Indirect comparisons were conducted using the proportion of patients experiencing adverse events and confirmed with single-arm meta-analyses and sensitivity analyses. Data were extracted from three PFA publications including a total of 497 patients and six CBA studies including a total of 1113 patients. The analysis revealed that PFA was associated with significantly lower risk of major adverse events {risk difference-4.3% [95% confidence interval (CI)-5.8,-2.8]; risk ratio 0.16 [95% CI 0.07, 0.45]} and prespecified adverse events [risk difference -2.5% (95% CI-4.4,-0.5); risk ratio 0.53 (95% CI 0.31, 0.96)]. Meta-analyses confirmed the lower rate of major adverse events for PFA [0.4% (95% CI 0.0, 1.3)] vs. CBA [5.6% (95% CI 2.6, 8.6)] and prespecified adverse events for PFA [2.7% (95% CI 1.2, 4.1)] vs. CBA [5.8% (95% CI 2.7, 9.0)]. Sensitivity analyses exploring heterogeneity across studies confirmed robustness of the main analyses. The findings of this study show that PFA has a more favorable safety profile than CBA, with significantly lower risks of major and prespecified adverse events. These indirect comparisons help contextualize the safety of PFA compared to CBA for the treatment of drug-refractory PAF in the absence of head-to-head studies.

Best practices in robotic magnetic navigation-guided catheter ablation of cardiac arrhythmias, a position paper of the Society for Cardiac Robotic Navigation.

Robotic magnetic navigation (RMN)-guided catheter ablation (CA) technology has been used for the treatment of cardiac arrhythmias for almost 20 years. Various studies reported that RMN allows for high catheter stability, improved lesion formation and a superior safety profile. So far, no guidelines or recommendations on RMN-guided CA have been published. The aim of this consensus paper was to summarize knowledge and provide recommendations on management of arrhythmias using RMN-guided CA as treatment of atrial fibrillation (AF) and ventricular arrhythmias (VA). An expert writing group, performed a detailed review of available literature, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Recommendations on RMN-guided CA are presented in a guideline format with three levels of recommendations to serve as a reference for best practices in RMN procedures. Each recommendation is accompanied by supportive text and references. The various sections cover the practical spectrum from system and patient set-up, EP laboratory staffing, combination of RMN with fluoroscopy and mapping systems, use of automation features and ablation settings and targets, for different cardiac arrhythmias. This manuscript, presenting the combined experience of expert robotic users and knowledge from the available literature, offers a unique resource for providers interested in the use of RMN in the treatment of cardiac arrhythmias.

Catheter Ablation of Persistent AF-Where are We Now?

Persistent atrial fibrillation (AF) is a diverse condition that includes various subtypes and underlying causes of arrhythmia. Progress made in catheter ablation technology in recent years has significantly enhanced the durability of ablation. Despite these advances however, the effectiveness of ablation in treating persistent AF is still relatively modest. Studies exploring the mechanisms behind persistent AF have identified substrate-driven focal and re-entrant sources within the atrial body as crucial in sustaining AF among individuals with persistent AF. Furthermore, the widespread adoption of atrial late gadolinium enhancement cardiac magnetic resonance (CMR) imaging and the ongoing refinement of invasive voltage mapping techniques have allowed for detailed assessment of fibrotic remodelling prior to or at the time of procedure. Translation into clinical practice, however, has yielded overall disappointing results. The clinical application of AF mapping in ablation procedures has not shown any substantial advantages beyond the use of pulmonary vein isolation (PVI) alone and adjunct ablation of fibrotic areas has yielded conflicting results in recent randomized trials. The emergence of pulsed field ablation represents a welcome development in the field and several studies have demonstrated an enhanced safety profile and increased procedural efficiency with this non-thermal energy modality. Pulsed field ablation also holds promise for safe and efficient substrate ablation beyond the pulmonary veins, but further trials are needed to assess its impact on longer term success rates. Continued advancements in our comprehension of AF mechanisms, alongside ongoing developments in catheter technology aimed at safe formation of transmural lesions, are essential for achieving better clinical outcomes for patients with persistent AF.

Catheter ablation technologies for persistent atrial fibrillation: controversies and evaluation

Catheter ablation technologies for persistent atrial fibrillation: controversies and evaluation

Bayesian network meta-analysis comparing hot balloon, laser balloon and cryoballoon ablation as initial therapies for atrial fibrillation.

Balloon-based catheter ablation (CA) technologies, including hot balloon ablation (HBA), laser balloon ablation (LBA) and cryoballoon ablation (CBA) have been introduced in recent years as alternatives to conventional radiofrequency ablation therapy for atrial fibrillation (AF). However, the results remain controversial concerning the optimal approach. Thus, we conducted a network meta-analysis (NMA) to comprehensively evaluate the efficacy and safety of HBA, LBA and CBA. Clinical trials comparing the efficacy and safety of HBA, LBA and CBA were identified through a systematic search up to October 2022. The primary outcomes of interest were the recurrence of AF and procedure-related complications. Twenty clinical trials with a total of 1,995 patients were included in the meta-analysis. The NMA results demonstrated that HBA, LBA and CBA had comparable AF recurrence rates (HBA vs. CBA: odds ratio OR = 0.88, 95% credible interval CrI: 0.56-1.4; LBA vs. CBA: OR = 1.1, 95% CrI: 0.75-1.5; LBA vs. HBA: OR = 1.2, 95% CrI: 0.70-2.0) and procedure-related complications (HBA vs. CBA: OR = 0.93, 95% CrI: 0.46-2.3; LBA vs. CBA: OR = 1.1, 95% CrI: 0.63-2.1; LBA vs. HBA: OR = 1.2, 95% CrI: 0.44-2.8). The surface under the cumulative ranking curve (SUCRA) suggested that HBA may be the optimal approach concerning the primary outcomes (SUCRA = 74.4%; 61.1%, respectively). However, HBA (40.1%) had a significantly higher incidence of touch-up ablation (TUA) than LBA (8.5%, OR = 2.8, 95% CrI: 1.1-7.1) and CBA (11.9%, OR = 3.7, 95% CrI: 1.9-7.5). LBA required more procedure time than CBA [mean difference (MD = 32.0 min, 95% CrI: 19.0-45.0 min)] and HBA (MD = 26.0 min, 95% CrI: 5.6-45.0 min), but less fluoroscopy time than HBA (MD = -9.4 min, 95% CrI: -17.0--2.4 min). HBA, LBA and CBA had comparable efficacy and safety as initial treatments for AF. HBA ranked highest in the primary outcomes, but at the cost of a higher incidence of TUA and longer fluoroscopy time. www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022381954, identifier: CRD42022381954.

Pulsed-field ablation in patients with permanent pacemaker or implantable cardioverter defibrillator: Is it safe?

Abstract Funding Acknowledgements Type of funding sources: None. Aims Pulse field ablation (PFA) is a novel catheter ablation technology with safety benefits due to its tissue selectivity. The risk of physical damage or electromagnetic interference (EMI) of PFA with cardiac implantable electronic devices (CIEDs) is unknown. The aim of our study was to assess the risk of PFA for CIEDs. Methods PFA lesions (45 per CIED) were applied to CIEDs (&amp;lt;5cm from the lead tip and &amp;lt;15cm from the generator). All devices were checked before and after PFA application for sensing and pacing parameters as well as integrity of shock circuits in ICDs using a heart simulator. Devices were interrogated for any spontaneous reprogramming, mode switching or other EMI effects. Results In total, 44 CIEDs were tested (16 pacemaker, 21 ICDs, 7 CRT-P/D) with 1,980 PFA applications. There was no change in device settings, functionality, electrical parameters and there was no visible damage to the CIEDs or leads. The risk on a device-based analysis is 0/44 (95% CI 0%-8%) and on a PFA pulse-based analysis is 0/1,980 (95% CI 0%-0.2%). Clinically relevant EMI appeared with oversensing and pacing inhibition, but not tachycardia detection. Conclusions Bipolar PFA appears safe and does not result in damage to CIEDs or leads. Clinically relevant EMI does occur, but appropriate peri-procedural programming may mitigate this. In-vivo studies are needed to confirm our findings.

Pulmonary vein isolation and additional selective ablation of low voltage areas and atrial late potentials for persistent atrial fibrillation (SOLVE-AF-Study)

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Abbott Introduction Novel catheter ablation technologies (e.g. RF with contiguous lesions) for pulmonary vein isolation (PVI) achieve high (80-85%) arrhythmia freedom rates at 12 months in both paroxysmal and persistent AF. However, success rates are importantly reduced (45-50%) in persistent AF patients presenting atrial cardiomyopathy with additional low voltage areas in the left atrial body. Aim SOLVE-AF study is a prospective randomized multicenter study, in which the standard approach "circumferential PVI" is compared to "additional ablation of low voltage areas and ablation of slow conducting "atrial late potentials (ALPs)" during sinus rhythm (SR)". Methods 320 patients with persistent AF will be included. Patients undergo left atrial high definition voltage mapping in SR. 160 patients with low voltage areas (&amp;lt;0.5mV at &amp;gt;5cm2) within the LA body will be randomized to "circumferential-PVI" vs. "additional low-voltage-guided ablation". The remaining 160 without low voltage substrate (registry group) will undergo "circumferential-PVI". Arrhythmia recurrences (defined as AF/AT &amp;gt;30 sec) will be assessed at 6 and 12 months (7-day-Holter and event-recorder) following ablation therapy (top panel). Results Currently, 120 patients have been included into the registry group and 120 patients with low voltage substrate have been randomized. Results of the SOLVE-AF-pilot study including a total of 210 patients (110 registry patients without LA-LVS and 100 patients with LA-LVS who were assigned to PVI-only versus additional substrate-based ablation) at the University-Heart-Center-FR-BK favor "PVI plus substrate-based ablation" in those patients who do present significant low voltage areas (see KM-curve bottom panel). Conclusions Results from the pilot trial suggests improved arrhythmia freedom rate with PVI plus additional substrate-based ablation during sinus rhythm. Final results of the prospective randomized multi-center trial SOLVE-AF are expected in June 2024.

CI-452768-2 PULSED-FIELD ABLATION IN PATIENTS WITH PERMANENT PACEMAKER OR IMPLANTABLE CARDIOVERTER DEFIBRILLATOR: IS IT SAFE?

Pulse field ablation (PFA) is a novel catheter ablation technology with safety benefits due to its tissue selectivity. The risk of physical damage or electromagnetic interference (EMI) of PFA with cardiac implantable electronic devices (CIEDs) is unknown. The aim of our study was to assess the risk of PFA for CIEDs. PFA lesions (45 per CIED) were applied (Farapulse, Boston Scientific, MA, USA) to CIEDs (<5cm from the lead tip and <15cm from the generator). All devices were checked before and after PFA application for sensing and pacing parameters as well as integrity of shock circuits in ICDs using a heart simulator. Devices were interrogated for any spontaneous reprogramming, mode switching or other EMI effects. In total, 44 CIEDs were tested (16 pacemaker, 21 ICDs, 7 CRT-P/D) with 1,980 PFA applications. There was no change in device settings, functionality, electrical parameters and there was no visible damage to the CIEDs or leads. The risk on a device-based analysis is 0/44 (95% CI 0%-8%) and on a PFA pulse-based analysis is 0/1,980 (95% CI 0%-0.2%). Clinically relevant EMI appeared with oversensing and pacing inhibition, but not tachycardia detection. Bipolar PFA appears safe and does not result in damage to CIEDs or leads. Clinically relevant EMI does occur, but appropriate peri-procedural programming may mitigate this. In-vivo studies are needed to confirm our findings.

Comparison of radiofrequency ablation and antiarrhythmic drug for the treatment of atrial fibrillation: A protocol for systematic review and meta-analysis

Antiarrhythmic drugs and radiofrequency ablation are first-line treatments of atrial fibrillation, however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus antiarrhythmic drugs as an early rhythm strategy. We performed a protocol for systematic review and meta-analysis to compare the efficacy and safety of radiofrequency ablation and antiarrhythmic drugs for the treatment of atrial fibrillation. This review protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022375095). Additionally, this review will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols 2015 Statement. A computerized literature search will be performed in the following electronic databases from their inceptions to November 2022: PubMed, EMBASE, MEDLINE, Cochrane Central Register of Controlled Clinical Trials, China Knowledge Resource Integrated Database, Wanfang Data Information, and Weipu Database for Chinese Technical Periodicals. The risk of bias will be assessed independently by 2 authors using the Cochrane tool of risk of bias. All statistical analyses will be conducted using the software program Review Manager version 5.3. The results of this systematic review will be published in a peer-reviewed journal. This study provides evidence of the comparison of radiofrequency ablation and antiarrhythmic drugs for the treatment of atrial fibrillation.

PO-624-07 ADVERSE EVENTS OF PENTARAY CATHETER VERSUS HIGH DENSITY GRID CATHETER : A REVIEW OF MAUDE DATABASE

Catheter ablation (CA) technology has evolved quickly leading to innovative multipolar mapping catheters with unique shapes and material. While these catheters have tremendously helped in reducing the procedural time and increasing the mapping resolution, they can potentially lead to increased procedural complications, a facet of practice that has not been compared head to head between the two leading multipolar catheters i.e Biosense Webster Pentaray catheter (PA) and Ensite high density mapping catheter (HD Grid).

PO-711-07 NETWORK META-ANALYSIS OF OPTIMAL INITIAL ATRIAL FIBRILLATION THERAPIES: CRYOABLATION, RADIOFREQUENCY ABLATION, AND ANTI-ARRHYTHMIC DRUGS

Antiarrhythmic drugs (AADs) and catheter ablation are first-line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of various catheter ablation technologies versus AADs as an early rhythm strategy.

Long-Term Cost-Effectiveness Comparison of Catheter Ablation and Antiarrhythmic Drugs in Atrial Fibrillation Treatment Using Discrete Event Simulation

ObjectivesTo evaluate the lifetime cost-effectiveness of 3 widely used atrial fibrillation (AF) treatments from the perspectives of Chinese healthcare system: antiarrhythmic drugs (AADs), ThermoCool SmartTouch guided by ablation index (STAI), and second-generation cryoballoon (CB2). MethodsA discrete event simulation (DES) model was implemented to compare the lifetime cost-effectiveness of AADs, STAI, and CB2. AF disease progression was explicitly modeled based on the Atrial Fibrillation Progression Trial clinical study results. The base-case analysis assumed that patients with paroxysmal AF (PAF) entered the model at the age of 55 years and had a CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ( > 65 = 1 point, > 75 = 2 points), Diabetes, previous Stroke/transient ischemic attack (2 points)-Vascular disease (peripheral arterial disease, previous myocardial infarction, aortic atheroma), Age 65 to 74 years, and Sex category) score of 2 for males and 3 for females. Model parameter uncertainties were incorporated throughout the DES simulation with full probabilistic model parameterization. ResultsThe lifetime cost-effectiveness evaluations showed that patients treated with AADs gained an average of 4.98 quality-adjusted life-years (QALYs) and 9.63 life-years (LYs) at an average cost of US dollar (USD) 15 374. Patients treated with CB2 gained 5.92 QALYs and 10.74 LYs at an average cost of USD 26 811. The STAI group gained an average of 6.55 QALYs and 11.57 LYs at an average cost of USD 24 722. The incremental cost-effectiveness ratios was USD 5927 and USD 12 167 per QALY for STAI versus AADs and CB2 versus AADs, respectively. Assuming the willingness-to-pay threshold for China is USD 30 390 per QALY, both ablation treatments will be cost-effective compared with AADs for patients with PAF. ConclusionsThe DES model demonstrated that catheter ablations are more cost-effective than AADs for patients with PAF under the healthcare system in China. Among catheter ablation technologies, STAI provides better outcomes at lower costs.

Bayesian network meta-analysis comparing cryoablation, radiofrequency ablation, and antiarrhythmic drugs as initial therapies for atrial fibrillation.

Antiarrhythmic drugs (AADs) and catheter ablation are first line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus AADs as an early rhythm strategy. To assess the safety and efficacy of cryoablation versus radiofrequency ablation (RFA) versus AADs as a first line therapy of PAF. MEDLINE, Embase, Scopus and CENTRAL were searched to retrieve randomized clinical trials (RCTs) comparing cryoablation, RFA or AADs to one another as first line therapies for atrial fibrillation (AF). The primary outcome was overall freedom from arrhythmia recurrence (AF, atrial flutter [AFL], atrial tachycardia). Secondary outcomes included freedom from symptomatic arrhythmia recurrence, hospitalization, and serious adverse events. A random-effects Bayesian network meta-analysis was used to calculate odds ratios (OR) and 95% credible intervals (CrI). Six RCTs (N = 1212) met the inclusion criteria (605 AADs, 365 Cryoablation, and 245 RFA). Compared with AADs, overall recurrence was reduced with RFA (OR: 0.31; 95% CrI: 0.10-0.71) and cryoablation (OR: 0.39; 95% CrI: 0.16-1.00). Comparing ablation (cryoablation and RFA) with AADs in respect to freedom from symptomatic AF recurrence, neither cryoablation (OR: 0.35; 95% CrI: 0.06-1.96) nor RFA (OR: 0.34; 95% CrI: 0.07-1.27) resulted in statistically significant reductions individually compared to AADs, though pooled ablation with both technologies showed lower odds of arrhythmia recurrence (OR: 0.35; 95% CrI: 0.13-0.79). In terms of serious adverse events rates, neither cryoablation (OR: 0.77; 95% CrI: 0.44-1.39) nor RFA (OR: 1.45; 95% CrI: 0.67-3.23) were significantly different to AADs. RFA resulted in a statistically significant reduction in hospitalizations compared to AAD (OR: 0.08; 95% CrI: 0.01-0.99), whereas cryoablation did not (OR: 0.77; 95% CrI: 0.44-1.39). The surface under the cumulative ranking curve showed RFA to be the most effective treatment at reducing overall rates of recurrence, symptomatic recurrence and hospitalizations; whereas cryoablation was most likely to reduce serious adverse events. Cryoablation and RFA are both effective and safe first line therapies for AF compared to AADs, with RFA being the most effective at reducing recurrences.

B-PO05-073 THE FASTR-AF TRIAL: ASSESSING THE DIAMOND TIP TEMPERATURE-CONTROLLED RADIOFREQUENCY ABLATION CATHETER TO TREAT PATIENTS WITH ATRIAL FIBRILLATION

Catheter ablation (CA) technology evolves as practitioners look to improve treatment options for atrial fibrillation (AF). A novel diamond tip, irrigated, radiofrequency (RF) ablation system accurately measures tip-tissue temperature in real-time and modulates power to maintain a target therapeutic tissue temperature. Recently, the DiamondTemp Ablation (DTA) system demonstrated strong outcomes against a contact force-sensing RF ablation system in a paroxysmal AF (PAF) population. However, no data pertaining to persistent AF (PsAF) has been reported in literature. This study sought to characterize the performance of the DTA system for the treatment of patients with drug-refractory PAF and PsAF with the second-generation RF DTA generator. DIAMOND FASTR-AF (NCT03626649) was a prospective, single-arm, multicenter European trial. Primary effectiveness endpoint was freedom from atrial arrhythmia recurrence following a 90-day blanking period through 12 months. Primary safety endpoint was a composite of serious adverse events. In total, 60 subjects (34 PAF and 26 PsAF) underwent CA with the DTA system at three centers. Patient demographics were consistent with contemporary AF studies (male 71.7%, age 63.9 ± 10.2 yrs, AF history 3.1 ± 3.9 yrs, LA size 4.4 ± 0.8 cm). The PAF cohort showed marked procedural efficiencies, as compared to PsAF, in total procedure time (76.9 ± 21.7 min vs 108.9 ± 33.6 min, p<0.001, respectively), total RF time (10.4 ± 3.5 min vs 20.4 ± 8.0 min, p<0.001), and number of RF applications (62.1 ± 25.3 vs 109.5 ± 45.5, p<0.001). Pulmonary vein isolation only was performed in 82% of PAF and 23% of PsAF subjects. Additional left-sided lesions were performed in 69% of PsAF subjects (vs 6% of PAF subjects). Safety event rate in the PAF and PsAF groups were 5.9% (2/34) and 11.5% (3/26), respectively. Freedom from recurrence was observed in 67.6% (23/34) of PAF and 61.5% (16/26) of PsAF subjects. The DiamondTemp Ablation system demonstrated long-term safety and effectiveness through 12 months post-ablation for patients with PAF or PsAF. Procedures were demonstrated to be highly efficient, with shorter time and fewer applications seen in PAF procedures.

A novel local impedance algorithm and contact force sensing to guide high power short duration radiofrequency ablation is efficient and safe for circumferential pulmonary vein isolation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Local impedance (LI) drop can predict sufficient lesion formation during radiofrequency ablation (RF). Recently, a novel ablation catheter technology able to measure LI and contact force has been made available for clinical use. High power short duration (HPSD) RF ablation has been shown to be feasible for atrial fibrillation (AF) ablation with short procedure time. We used LI drop and plateau formation to guide duration of 50 Watt RF power applications for circumferential pulmonary vein isolation (PVI). Methods Consecutive patients with indication for de novo AF ablation (n = 32, age 65 ± 10 years) with paroxysmal (n = 16) or persistent (n = 16) AF underwent ultra high density 3D mapping of the left atrium and catheter ablation. Thereafter, ipsilateral PV encircling with 50 Watt RF-applications targeting an interlesion distance of ≤ 6mm and a contact force of 10-30g was performed. Duration of HPSD RF application between 7-15s was guided by impedance drop &amp;gt;20 Ohm and plateau formation of LI. Further ablation strategy was left to the investigator’s discretion. Esophageal temperature measurement was performed using a three thermistor catheter with temperature cut off 39.0°C. In case of temperature rise or very near esophageal contact to the circumferential line, RF application time was shortened to 7s. Patients underwent adenosine testing after PVI. Previously we performed all types of AF ablation using an LI guided HPSD ablation without contact force measurement capability in 80 patients. Results Complete PVI was achieved in all pts with only 13.5 ± 4.3 min cumulative RF application duration and an ablation procedure duration of 46.5 ± 10.4 min with the novel LI measuring catheter. First-pass isolation of ipsilateral veins was achieved in 75% of circles. Recurrence of PV conduction during waiting period (20min) and adenosine testing occured in 25% of circles, and was reablated in most patients with a single spot of HPSD application. Using 94 ± 36 RF application per patient, mean maximum LI drop was 23.6 ± 4.0 Ohm. Reconnected fibers were associated with low LI drop due to instability of contact in most cases due to breathing in case of difficult sedation of the patients. No serious complications occurred in all 32 pts using HPSD with the novel contact force catheter design. Conclusion Guiding of HPSD RF ablation by LI is highly efficient and safe. A novel local impedance algorithm in combination with contact force sensing enable short PVI times with low early recurrence of PV conduction. Prediction of permanent lesions seems possible and the only limitation seems to be unstable RF catheter contact due patients breathing. Follow up have to be waited.

Impact of Micro-, Mini- and Multi-Electrode Mapping on Ventricular Substrate Characterisation.

Accurate substrate characterisation may improve the evolving understanding and treatment of cardiac arrhythmias. During substrate-based ablation techniques, wide practice variations exist with mapping via dedicated multi-electrode catheter or conventional ablation catheters. Recently, newer ablation catheter technology with embedded mapping electrodes have been introduced. This article focuses on the general misconceptions of voltage mapping and more specific differences in unipolar and bipolar signal morphology, field of view, signal-to-noise ratio, mapping capabilities (density and resolution), catheter-specific voltage thresholds and impact of micro-, mini- and multi-electrodes for substrate mapping. Efficiency and cost-effectiveness of different catheter types are discussed. Increasing sampling density with smaller electrodes allows for higher resolution with a greater likelihood to record near-field electrical information. These advances may help to further improve our mechanistic understanding of the correlation between substrate and ventricular tachycardia, as well as macro-reentry arrhythmia in humans.

Quantitative analysis of the isolation area after larger-size laser balloon ablation

Abstract Background The visually guided laser balloon ablation is a balloon-based catheter ablation technology used for atrial fibrillation (AF) ablation in recent years. This balloon catheter consists of a compliant balloon that has the capability of real-time endoscopic visualization of the targeted pulmonary vein (PV). The sizeable balloon is usually inflated to obtain optimal PV occlusion. The isolation area after laser balloon (LB) ablation was reported to be smaller than that after cryoballoon ablation. However, when LB is inflated with its maximum pressure, it can visualize wide-area PV antrum. Thereby, we suspected that larger-size LB can create wider isolation area. Purpose The aim of this study is to quantitatively evaluate the isolation area after LB ablation at the size larger than appropriate size for ablation in the pulmonary vein carina region. Methods We assessed 66 patients with AF who underwent LB ablation at the larger inflation size in our hospital during the period from July 2018 to July 2019. After LB ablation, we created voltage maps with a circular mapping catheter and calculated isolation areas with CARTO system. Results Figure shows a larger LB with its maximum pressure. PV antrum isolation was extended to the posterior wall in all patients. The left- and right-sided pulmonary vein antrum isolation area were 15.1±3.9 and 19.4±4.3 cm2, respectively. Conclusion LB at the larger inflation size with its maximum pressure can isolate wider-area circumferential PV antrum than previously reported. This method may be a new way of pulmonary vein antrum isolation. Left atrial voltage mapping after PVI. Funding Acknowledgement Type of funding source: None

Systematic review and network meta-analysis of atrial fibrillation percutaneous catheter ablation technologies using randomized controlled trials.

We sought out to make comparisons between all atrial fibrillation (AF) catheter ablation technologies using randomized controlled trial data. Our comparisons were freedom from AF, procedural duration, and fluoroscopy duration. Searches were made of EMBASE, MEDLINE, and CENTRAL databases, and studies were selected which had cryoballoon, conventional radiofrequency (RF), multipolar RF catheters, and laser technology as an arm in the study and were identified as randomized controlled trials (RCTs). These studies were analyzed for direct comparisons using conventional meta-analysis and a combination of indirect and direct comparisons via a network meta-analysis (NMA). With respect to freedom from AF both direct comparisons and NMA did not demonstrate any significant difference. However in analysis of procedural and fluoroscopy duration (minutes) for the pulmonary vein ablation catheter (PVAC), both conventional analysis and NMA revealed significantly shorter procedure times, RF vs PVAC (conventional: 61.99 [38.03-85.94], P <.00001; NMA: 54.76 [36.64-72.88], P < .0001) and fluoroscopy times, RF vs PVAC (conventional: 12.96 [6.40-19.53], P = .0001; NMA: 8.89 [3.27-14.51], P < .01). The procedural duration was also shorter for the cryoballoon with NMA, RF vs CRYO (20.56 [3.47-37.65], P = .02). Our analysis demonstrated that while there was no difference in the efficacy of the individual catheter technologies, there are significant differences in the procedural duration for the PVAC and the cryoballoon. While they may seem an attractive solution for high-volume centers, further RCTs of next-generation technologies should be examined.