Left Atrial Posterior Wall Research Articles

Ablation outcome in patients with atrial fibrillation undergoing ICE-guided pulsed-field ablation

Abstract Background Prior experiences from preclinical studies indicate the critical need of catheter-tissue- contact for creation of consistent transmural lesions in pulsed-field ablation (PFA). Intracardiac echocardiography (ICE) not only provide real-time visualization of cardiac structures, but also ensure adequate contact with the tissue. Objective We evaluated ablation outcome and reconnection rate following ICE-guided PFA procedure in patients with atrial fibrillation (AF). Methods Consecutive patients receiving ICE-guided PFA procedure were included in this multi-center analysis. All patients received isolation of PVs (PVI). Additional ablation of left atrial posterior wall (LAPW) was decided based on operator’s discretion. Concentric overlapping lesions were placed in the LAPW. Number of applications were determined on a case-by-case basis. ICE and fluoroscopy were used to optimize contact between the PFA catheter and the targeted tissue. All procedures were performed under uninterrupted anticoagulation. Mapping was done before and after ablation to confirm electrical isolation. Arrhythmia-monitoring was done for 1-year with periodic clinic visits, event recorders and 7-day Holter monitoring. Results A total of 372 patients [age: 62.69 ± 10.41 years, male: 201 (71.3%), paroxysmal AF: 67 (18%)] were included in this analysis of which 48 (12.9%) underwent PVI-only and the remaining subjects received additional ablation of LAPW. Mean number of applications were 34.67 ± 8.88 and 73.65 ± 37.21 for PVI-only and PVI+LAPWI cohorts respectively (p<0.001). No major procedural complications such as esophageal injury, atrio-esophageal fistula, pericardial effusion requiring drainage or cerebrovascular accidents were reported. During 1-year follow-up, 38 (10.2%) patients underwent repeat procedure for recurrence. Reconnection of PV and LAPW were found in only 2 (5.2%) patients. In all 38 patients, new triggers initiating AF were detected to be originating from interatrial septum: 25 (65.8%), superior vena cava: 9 (23.7%), coronary sinus: 7 (18.4%) and left atrial appendage: 6 (15.8%). Conclusion ICE-guided PFA procedures are safe and produce durable lesions leading to very low reconnection rate. The recurrence was mostly due to new triggers initiating AF.

Ablation outcome in elderly women with atrial fibrillation undergoing pulsed-field ablation for electrical isolation of pulmonary veins and left atrial posterior wall

Abstract Background Documented evidences indicate higher prevalence of non-paroxysmal atrial fibrillation (AF) as well as in elderly women but also demonstrate the need to go beyond the pulmonary veins (PV) when treating these patients. Objective We compared the ablation outcome in elderly women (>70 years) with that in men in the same age group as well as in younger women (≤70 years) undergoing pulsed-field ablation (PFA) for persistent AF (PerAF). Methods This multicenter study included consecutive PerAF patients undergoing PFA as their first procedure. Patients were divided into 3 groups: Group 1: women >70 years, Group 2: men ≥70 years and Group 3: women ≤70 years. All received PV isolation (PVI) and isolation of left atrial posterior wall (LAPWI). Concentric overlapping lesions were placed in the LAPW. Number of applications were determined on a case-by-case basis. Isolation was confirmed by electrograms recorded on the multispline catheter. In all patients, ICE and fluoroscopy were used to optimize contact between the PFA catheter and the targeted tissue. Arrhythmia-monitoring was performed for 1-year with periodic clinic visits, event recorders and 7-day Holter monitoring. Results A total of 229 patients (group 1: 73; group 2: 47 and group 3: 109) were included in this analysis. Baseline characteristics of the study population is presented in table 1. At 1-year follow-up, 15 (20.5%), 3 (6.38%) and 10 (9.17%) from group 1, 2 and 3 respectively, experienced arrhythmia recurrence off-antiarrhythmic drugs. Recurrence rate in group 1 was significantly higher than that in group 2 (p=0.034) and group 3 (p=0.029). Conclusion In women aged ≤70 years and in elderly men (>70 years), PVI plus isolation of LAPW using ICE-guided PFA was associated with significantly lower recurrence rate compared to that in the elderly women. Given the higher recurrence rate following PVI+LAPWI in the elderly females, the operators should consider addressing all other AF-initiating extra-PV triggers for better ablation-outcome in this subset of the AF population.

Organization of atrial flutter during pulse field ablation for atrial fibrillation

Abstract Background Pulse Field Ablation (PFA) has been acknowledged as an effective and safe tool for ablation of Atrial Fibrillation (AF). It is known that during AF ablation, the arrhythmia may organize into atrial flutter. The left atrial posterior wall is identified as a critical source of non-Pulmonary Vein (PV) triggers that facilitate maintenance of atrial fibrillation. Objective The purpose of this study is to investigate the phenomenon of atrial flutter organization from AF during the application of PFA. Methods This prospective multicentric study encompasses 117 consecutive patients with persistent AF across American and European institutions, undergoing first time catheter ablation. All receive isolation of the Pulmonary Veins (PV) plus Posterior Wall (PW) isolation. The PW isolation procedure targeted the standard area between the PVs and extended to the area demarcated by the line connecting the inferior borders of the inferior PV-encircling lesions to the coronary sinus defined lower part of PW (Fig. 1). The study documented the specific locations where AF organized into atrial flutter with a stable cycle length during PFA. Results Organization of AF to atrial flutter during PFA was observed in 72 (61.5%) patients. Analysis of the organization of flutter revealed that in 41 (56.9%) of these cases, flutter began while ablating the lower part of the PW. Moreover, 9 (12.5%) initiated at one of the PVs, and 22 (30.5%) during the ablation of the posterior wall. Notably, the flutter was described as perimitral flutter in 33 (45.8%), as typical flutter in 24 (33.3%), and as roof-dependent flutter in 15 (20.8%) of cases. Conclusion The findings underscore that during PFA for AF, there is a pronounced tendency for the arrhythmia to organize into atrial flutter, particularly during the ablation of the lower posterior wall. Notably ablation in the left atrium organized AF in typical atrial flutter at a considerable rate.Ablation on lower part of PW

Unipolar electroanatomical mapping outperforms bipolar voltage in detecting LGE areas in the left atrium

Abstract Introduction In atrial fibrillation (AF) management, understanding left atrial substrate is crucial. While both electroanatomical mapping (EAM) and late gadolinium enhancement MRI (LGE MRI) are reliable methods in assessing atrial substrate and are associated with the ablation outcome, recent findings have highlighted significant discrepancies between bipolar low voltage areas (LVA) in EAM and LGE areas. Objective Explore the relationship between LGE areas and unipolar LVAs by utilizing multipolar high-density (HD) mapping. Methods Nineteen patients scheduled for AF ablation underwent pre-ablation LGE-MRI. Left atrial (LA) segmentation was conducted using a convolutional neural network, which subsequently generated a 3D mesh integrating the LGE data. HD-EAM was performed in sinus rhythm for each patient, capturing at least 4000 points. The EAM map and LGE MRI mesh were co-registered. LVA areas were defined using voltage cut-offs of 0.5 mV for bipolar and 2.5 mV for unipolar measurements. Correspondence between LGE areas and LVAs on the anterior and posterior LA wall was analyzed. Results Both bipolar and unipolar LVA demonstrated high precision in detecting LGE areas (100% and 88% respectively). However, unipolar LVA exhibited a remarkable accuracy of 81% for detecting LGE areas specifically, whereas bipolar LVA displayed a significantly lower accuracy of 28%. These findings were consistent across the different atrial walls. Conclusion Incorporating unipolar voltage data into electroanatomical mapping in the atrium may bridge the observed gap between LGE areas and bipolar LVAs. Our findings highlight the significance of unipolar voltage in evaluating the left atrial substrate, potentially offering a more comprehensive insight into the different layers of atrial walls, and opening the door for new approaches in AF therapy.

High density mapping accuracy and efficiency in atrial fibrillation: real-world outcomes from the SECURE registry

Abstract Background/Introduction A high-density (HD) mapping catheter is valuable for validating pulmonary vein isolation (PVI) and analysing arrhythmic substrates of the left atrium (LA) during atrial fibrillation (AF) ablation. Multiple HD mapping catheters are available for use in clinical practice. A novel octa-spline mapping catheter with a close internal unipolar reference electrode is now available and may improve mapping efficiencies and image resolutions (Figure). Purpose This study aims to report real-world experiences with different commercially available HD mapping catheters in AF ablation and compare mapping performance. Methods SECURE is an ongoing observational, prospective, post-marketing study collecting real-world data on ablation procedures performed per standard-of-care. At the time of data extraction (Nov. 2023), 16 sites across 8 countries had enrolled 2,366 patients (pts), with 12-month follow-up data available for 828 pts. The current analysis, which included consecutive pts undergoing AF ablation, evaluated mapping efficiency and procedural outcomes with 3 HD mapping catheters: circular catheter (CC), penta-spline catheter (PSC), and octa-spline catheter (OSC). Mapping data were analysed with a cloud-based data management and artificial intelligence-powered algorithm. Results Overall, 859 pts with AF (paroxysmal AF [PAF], n=465; persistent AF [PsAF], n=240; long-standing PsAF [LS PsAF], n=154) were included in this analysis. The CC, PSC, and OSC were used in 428, 210, and 221 pts, respectively. Procedures using the OSC had a significantly higher mean mapping area (31,989.9 mm2) than those performed with the CC (23,152.2 mm2; P<0.0001) and PSC (29,804.6 mm2; P=0.0027), as well as a >3-fold higher mean mapping rate (138.4 vs 20.8 and 43.4 points/min, respectively; both P<0.0001). The higher number of mapping points translated to a higher mean mapping density (OSC, 0.34 vs CC, 0.05 and PSC, 0.07 points/mm2; both P<0.0001), with more uniform point distribution and less interpolation. With the CC, PSC, and OSC, respectively, total mean procedure times (incl PVI + other targets) were 118.0, 118.7, and 165.1 min, (P<0.0001 for OSC vs. both CC and PSC) and mean pre-ablation mapping times were 25.2, 25.0, and 21.5 min (P<0.0004 for OSC vs. both CC and PSC). The improved mapping quality and efficiency with the OSC allowed to include specific ablation targets beyond PVI. Fewer PVI-only procedures were performed with the OSC (29.4%) versus the CC (62.1%) and PSC (54.8%), while ablation of the PVI+ other targets was more common with the OSC versus the CC and PSC, including the cavotricuspid isthmus (37.1% vs 17.3% and 16.7%), LA roof (42.5% vs 13.1% and 21.4%), and LA posterior wall (21.7% vs 10.5% and 16.2%). Results were overall consistent per AF type (Table). Conclusions By providing more accurate mapping, the OSC allows for improved analysis of the arrhythmic substrate, which may improve ablation outcomes for pts with PAF and PsAF.Figure 1

Efficacy of the peak frequency map for left atrial posterior wall isolation.

Complete isolation of the left atrial posterior wall (LAPW) is challenging owing to overlapping epicardial conduction. Peak frequency (PF) is a novel parameter that focuses on near- and far-field electrogram components. In this study, we aimed to determine whether transmural block completion is related to the ablation site PF. We analyzed 44 consecutive patients undergoing initial LAPW isolation (LAPWI) between June 2023 and February 2024. Pre-LAPWI and PF maps were obtained using an HD-Grid catheter. In 17 of the 44 patients (Group-1), LAPWI was performed conventionally. In the remaining 27 patients (Group-2), PF-guided LAPWI was applied based on Group-1 results. In Group-1, the left atrial (LA) roof and floor line success rates were 58.8% and 76.5%, respectively. The average PF value in the roof lines of patients with a completed block line was significantly higher than that of the remaining patients (286.6 ± 29.3 Hz vs. 236.1 ± 40.9 Hz, p = .012), but the floor lines were similar. In Group-2, relatively high PF values were targeted to achieve complete block of the LA roof and floor lines, following the results obtained in Group-1. The LA roof line success rates (92.6% vs. 58.8%, p = .007), total number of radiofrequency (RF) applications (22.7 ± 5.6 vs. 27.6 ± 8.5, p = .03), and procedural time (32.6 ± 18.3 vs. 47.9 ± 25.6 min, p = .03) differed between Group-1 and Group-2. Using a PF map for determining the optimal ablation line for LAPWI by RF catheter ablation is feasible.

Comparative Effects of Different Power Settings for Achieving Transmural Isolation of the Left Atrial Posterior Wall with Radiofrequency Energy.

Comparative Effects of Different Power Settings for Achieving Transmural Isolation of the Left Atrial Posterior Wall with Radiofrequency Energy.

Outcomes of hybrid surgical ablation and concomitant left atrial appendage exclusion in long-standing persistent atrial fibrillation.

Management of patients with long-standing persistent atrial fibrillation (LSPAF) presents a clinical challenge. Hybrid convergent ablation has been shown to have superior efficacy compared to endocardial-only ablation. However, data on concomitant left atrial appendage (LAA) management along with hybrid ablation is sparse. We aimed to evaluate the effectiveness of concomitant hybrid convergent ablation and LAA clipping in patients with LSPAF. We conducted a retrospective analysis of all patients with LSPAF who underwent hybrid surgical ablation with LAA clipping at our institution. The primary endpoint was a recurrence of atrial arrhythmias at 12 months. Further, the durability of surgical left atrial posterior wall ablation was examined during the endocardial catheter ablation using standing electrophysiological criteria. A total of 79 patients were included. Mean age was 63.5 ± 9.6 years, and 71% were males. LAA clipping was performed in 99% of patients. The mean time between the surgical and endocardial stages of the procedure was 2.6 ± 1.7 months. Persistent posterior wall activity was observed in 34.2% (n = 27/79) patients during the endocardial phase of the procedure. Cardiac implantable electronic device was used in 74% of patients for monitoring of recurrence of atrial fibrillation (AF). The primary effectiveness of AF freedom at 12 months was 73.8% (45/61). Over a 12-month follow-up period, 11.4% (9/79) of patients required repeat catheter ablation, of which 88.9% (8/9) had evidence of persistent posterior wall activity. Concomitant hybrid convergent ablation and LAA exclusion with an atrial clip provides reasonable long-term AF-free survival in patients with LSPAF. Persistent posterior wall activity is seen commonly in patients presenting with recurrent AF following hybrid convergent AF ablation.

Catheter ablation for atrial fibrillation: indications and future perspective.

Recent advances in techniques, technologies and proven superiority over anti-arrhythmic drugs have made catheter ablation the cornerstone of management for atrial fibrillation (AF), which has shown a steady increase in prevalence in the ageing population worldwide. The aim of therapeutic interventions is to achieve stable sinus rhythm that would improve the quality of life and reduce the risk of AF-associated complications. Pulmonary veins (PVs) were first described as the source of initiation of ectopic triggers driving AF, which led to the establishment of PV isolation (PVI) as the most widely practiced procedure to treat AF. Antral PVI is still recognized as the stand-alone ablation strategy for newly diagnosed paroxysmal AF (PAF). However, in non-PAF patients, PVI seems to be inadequate and several adjunctive strategies, including ablation of left atrial posterior wall and non-PV triggers, AF mapping and ablation of rotors and drivers, ethanol infusion of vein of Marshall and renal denervation, etc. have been reported with mixed results. Recent trials have also documented the benefits of early rhythm control in preventing cardiovascular events in addition to slowing the progression of PAF to more persistent forms. Similarly, very late relapse of the arrhythmia after successful PVI has drawn attention to the critical role of non-PV triggers and highlighted their relevance as potential ablation targets during repeat procedures. Ablation technology is also under constant evolution with the introduction of non-thermal energy sources and new tools to create durable lesions. This review summarizes the indications, advancements, and future perspective of AF ablation.

Prognostic impact of diagnosis-to-ablation time on outcomes following catheter ablation in persistent atrial fibrillation and left ventricular systolic dysfunction

BackgroundThe optimal timing of catheter ablation in individuals with atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) remains uncertain. ObjectiveWe examined whether AF diagnosis to ablation time (DAT) influences outcomes following catheter ablation (CA) in patients with persistent AF (PsAF) and LVSD from the CAMERA-MRI and CAPLA randomized studies. MethodsWe evaluated clinical outcomes according to DAT < 1 year (“shorter DAT”) and ≥1 year (“longer DAT”), comparing AF recurrence, AF burden, left ventricular ejection fraction (LVEF), and LV recovery (LVEF ≥ 50%) at 12 months. DAT was also compared according to the median (24 months). ResultsTwo hundred and ten individuals with AF and LVSD were identified, with a median DAT of 24 months. Shorter DAT was associated with lower LA global and posterior wall scar (<0.05 mV; both P < .05). At 12 months, 69.4% with shorter DAT (<1year) were free from recurrent atrial arrhythmias vs 53.6% in longer DAT (hazard ratio [HR] 1.63, 95% confidence interval [CI] 1.01–2.65, P = .040). Median AF burden was 0% in both groups (shorter DAT: interquartile range [IQR] 0.0–2.0% vs longer DAT: IQR 0.0–7.3%, P = .017). At 12 months, shorter DAT was associated with higher LVEF (55.3% vs 51.0%, P = .009), greater LVEF improvement (+20.8 ± 13.0% vs +13.9 ± 13.2% longer DAT, P < .001) and LV recovery (75.0% vs longer DAT: 57.2%, P = .011). Shorter DAT was associated with fewer hospitalizations and electrical cardioversions at 12 months. ConclusionIn individuals with AF and LVSD, shorter DAT was associated with greater LVEF improvement and arrhythmia-free survival with lower AF burden and rehospitalization at 12 months, highlighting the prognostic benefit of early CA in AF and LVSD.

Left atrial posterior wall isolation in addition to pulmonary vein isolation using a pentaspline catheter in pulsed-field ablation for atrial fibrillation: a systematic review and meta-analysis

Left atrial posterior wall isolation in addition to pulmonary vein isolation using a pentaspline catheter in pulsed-field ablation for atrial fibrillation: a systematic review and meta-analysis

Persistent Atrial Fibrillation Phenotypes and Ablation Outcomes: Persistent From Outset vs Progression From Paroxysmal AF

BackgroundMany patients with persistent atrial fibrillation (PsAF) have progressed from an initial paroxysmal phenotype; however, there are patients in whom atrial fibrillation (AF) is persistent at diagnosis. Relatively little is known about this subgroup, but prior observational studies have suggested these patients have worse outcomes with ablation. ObjectivesThis study sought to: 1) assess demographic and electrophysiologic characteristics of patients with PsAF at first diagnosis compared with those with who have progressed from paroxysmal atrial fibrillation (PAF); and 2) assess the impact of pattern of AF at diagnosis on recurrence post ablation. MethodsCAPLA (Catheter Ablation for persistent atrial fibrillation: A Multicentre randomised trial of Pulmonary vein isolation [PVI] vs PVI with posterior Left Atrial wall isolation [PWI]) was a multicenter trial that randomized patients with PsAF to PVI plus PWI or PVI alone. Follow-up was 12 months. Outcomes were assessed after a 3-month blanking period. ResultsA total of 334 patients were included (median age 65.6 years, 23.1% female), 194 (58.1%) had PsAF at first AF diagnosis and 140 (41.9%) had PAF. Patients with PsAF at diagnosis were younger (age 64.0 vs 67.7 years, P = 0.005), had higher rates of heart failure (P < 0.001), and lower left ventricular ejection fraction (54.5% IQR: 40-60 vs 60% IQR: 50-61, P = 0.007). AF recurrence occurred in 85 (43.8%) with PsAF at diagnosis and 70 (50%) with PAF at diagnosis. PsAF at diagnosis was not associated with risk of recurrence on univariable (HR: 0.802; 95% CI: 0.585-1.101; P = 0.173) or multivariable analysis (HR: 0.922; 95% CI: 0.647-1.312; P = 0.650). Median AF burden was 0% in both groups (P = 0.125). There was no difference in left atrial size (P = 0.337) or bipolar voltage (P = 0.579) between the groups. ConclusionsIn the CAPLA cohort of patients, pattern of AF at first diagnosis did not influence post-ablation rate of AF recurrence or AF burden. (Catheter Ablation for persistent atrial fibrillation: A Multicentre randomised trial of Pulmonary vein isolation [PVI] vs PVI with posterior Left Atrial wall isolation [PWI]; ACTRN12616001436460)

Radiofrequency catheter ablation of persistent atrial fibrillation by pulmonary vein isolation with or without left atrial posterior wall isolation: long-term outcomes of the CAPLA trial.

Posterior wall isolation (PWI) is commonly incorporated into catheter ablation (CA) strategies for persistent atrial fibrillation (AF) in an attempt to improve outcomes. In the CAPLA randomized study, adjunctive PWI did not improve freedom from atrial arrhythmia at 12 months compared with pulmonary vein isolation (PVI) alone. Whether additional PWI reduces arrhythmia recurrence over the longer term remains unknown. In this multicenter, international, randomized study patients with persistent AF undergoing index CA using radiofrequency (RF) were randomized to PVI+PWI versus PVI alone. Patients underwent regular follow-up including rhythm monitoring for a minimum of 3 years post CA. AF burden at 3 years post-ablation was evaluated with either 28-day continuous ambulatory ECG monitoring, twice daily single-lead ECG or from cardiac implanted device. Evaluated endpoints included freedom from any documented atrial arrhythmia recurrence after a single procedure, AF burden, need for redo catheter ablation, rhythm at last clinical follow-up, healthcare utilisation metrics and AF-related quality of life. 333 of 338 (98.5%) patients (mean age 64.3±9.4 years, 23% female) completed 3-year follow-up, with 169 patients randomized to PVI+PWI and 164 patients to PVI alone. At a median of 3.62 years post-index ablation, freedom from recurrent atrial arrhythmia occurred in 59 patients (35.5%) randomized to PVI+PWI vs 68 patients (42.1%) randomized to PVI alone (HR 1.15, 95% CI 0.88-1.51, p=0.55). Median time to recurrent atrial arrhythmia was 0.53 years (IQR 0.34-1.01 years). Redo ablation was performed in 54 patients (32.0%) in the PVI+PWI group vs 49 patients (29.9%, p=0.68) in the PVI alone group. Pulmonary vein reconnection was present in 54.5% (mean number of reconnected PVs 2.2±0.9) and posterior wall reconnection in 75%. Median AF burden at 3 years was 0% in both groups (IQR 0-0.85% PVI+PWI vs 0-1.43% PVI alone, p=0.49). Sinus rhythm at final clinical follow-up was present in 85.1% with PVI+PWI vs 87.1% with PVI alone (p=0.60). Mean AF Effect On Quality-Of-Life (AFEQT) score at 3 years post-ablation was 88.0±14.8 with PVI+PWI vs 88.9±15.4 with PVI alone (p=0.63). In patients with persistent AF, the addition of PWI to PVI alone at index RF catheter ablation did not significantly improve freedom from atrial arrhythmia recurrence at long-term follow-up. Median AF burden remains low and AF quality of life high at 3 years with either ablation strategy.

Distribution of antral lesions with the novel size-adjustable cryoballoon for pulmonary vein isolation and the differences based on left atrial remodeling.

The novel cryoballoon with 28 mm or 31 mm adjustable diameters, aims to achieve a wide antral pulmonary vein isolation (PVI). However, the distribution of antral lesions and their variations based on left atrial (LA) remodeling require further clarification. We evaluated 22 patients (67 [59.5-74.8] years, 19 males) who underwent PVI of atrial fibrillation (AF) (13 paroxysmal AF [PAF] and 9 non-PAF) using size-adjustable cryoballoons. LA electro-anatomical mapping was performed post-PVI with three-dimensional mapping systems. We assessed the shapes of the LA and pulmonary veins (PVs) and the distribution of isolated areas (IAs), comparing the results between PAF and non-PAF patients. In the left PVs (LPVs), the distance between the PV orifice and IA edge (PVos-IA) was larger on the roof and posterior segments (~15 mm) but relatively smaller on the anterior segment near the PV ridge (<10 mm). For the right PVs (RPVs), it was more extensive in the posterior segment (10-15 mm). Comparing PAF and non-PAF, there were no significant differences in the PVos-IA except for the right posterior-carina segment, antrum IA (LPVs: 5.9 ± 1.6 vs. 5.8 ± 0.8 cm², p = .81; RPVs: 4.8 ± 2.3 vs. 4.8 ± 1.2 cm², p = .81), distances between the right and left IAs on the LA posterior wall (LAPW), and un-isolated LAPW area (9.0 ± 4.9 vs. 9.9 ± 2.5 cm², p = .62). No individual PVIs were observed in either group. Two patients exhibited overlapping IAs on the roof, and one patient who underwent 31 mm balloon applications for all PVs exhibited an LAPW isolation. The size-adjustable cryoballoon achieved a wide antral PVI even in non-PAF patients.

Clinical impact of cryoballoon posterior wall isolation using the cross-over technique in persistent atrial fibrillation.

Successful left atrial posterior wall isolation (LAPWI) using only the cryoballoon (CB) is technically challenging for the treatment of atrial fibrillation (AF). This study aimed to evaluate the efficacy of the cross-over technique, wherein an overlapped ablation is performed by placing the CB from both directions in contact with the LAPW. This was a single-center, retrospective, observational study of 194 consecutive patients with persistent atrial fibrillation (PerAF) who underwent a first-time procedure of pulmonary vein isolation (PVI)+PWI (108 patients) or PVI-only (86 patients) using the CB. The cross-over technique was applied in all LAPWI. For ablation of the LA roof and bottom, respectively, a mean of 8.6±1.0 (right to left [R→L] 4.3±1.1 and left to right [L→R] 4.3±1.1) and 9.1±1.2 (R→L 4.6±1.6 and L→R 4.5±1.2) CB applications were delivered. LAPW was successfully isolated solely using the CB in 99.1% of patients. Although the PVI+PWI group had significantly longer procedure time, no severe adverse events were observed in either group. During a median follow-up of 19 months, freedom from recurrence of all atrial tachyarrhythmias was achieved in 93.5% of the PVI+PWI group and 72.9% of the PVI-only group (p=.011). LAPWI performed solely with the CB using the cross-over technique is feasibly, safe, and was independently associated with a significantly higher freedom from recurrence of atrial tachyarrhythmias compared with PVI alone in patients with PerAF.

Comparative Analysis of Pulmonary Vein Isolation (PVI) Alone Versus PVI With Additional Left Atrial Posterior Wall Isolation by Pulsed Field Ablation: A Single-Centre Study

Comparative Analysis of Pulmonary Vein Isolation (PVI) Alone Versus PVI With Additional Left Atrial Posterior Wall Isolation by Pulsed Field Ablation: A Single-Centre Study

Adjunctive left atrial posterior wall isolation for atrial fibrillation: An updated systematic review and meta-analysis.

Posterior left atrial wall isolation (PWI) plus traditional pulmonary vein isolation (PVI) has been proposed as a promising intervention to decrease atrial fibrillation (AF) recurrence. We aim to investigate the efficacy and safety of adding PWI to the traditional PVI in patients with AF. A systematic review and meta-analysis was conducted using synthesizing randomized controlled trials (RCTs) retrieved by systematically searching PubMed, Web of Science, SCOPUS, EMBASE, and Cochrane through June 14, 2023. We used Stata version 17 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD), with a 95% confidence interval (CI) (PROSPERO ID: CRD42023446227). We included 11 RCTs with a total number of 1534 patients. Combined ablation with PWI + PVI was not associated with any significant difference over PVI only regarding the recurrence of clinical AF (RR: 0.86 with 95% CI [0.70-1.06]), all atrial arrhythmia (RR: 0.93 with 95% CI [0.82-1.07]), nonatrial fibrillation arrhythmia (RR: 1.22 with 95% CI [0.97-1.53]), early AF (RR: 0.89 with 95% CI [0.62-1.27]), and antiarrhythmic drugs at discharge (RR: 0.83 with 95% CI [0.67-1.04]). However, it was associated with increased total ablation duration (minutes) (MD: 12.58 with 95% CI [6.80-18.37]) and total procedure duration (minutes) (MD: 16.77 with 95% CI [9.63-23.91]), without any significant difference regarding adverse events (RR: 1.05 with 95% CI [0.63-1.74]). While the pooled data from PWI + PVI using point-by-point radiofrequency did not suggest a benefit in the recurrence of various atrial arrhythmias compared to PVI alone, PWI+PVI using direct posterior wall ablation, especially with cryoballoon, demonstrated a significant reduction in recurrence of AF/atrial arrhythmias. Also, PWI + PVI significantly increased the ablation and total procedure durations.

Lesion durability found during mandated percutaneous catheter ablation after surgical cryo-ablation for treatment of non-paroxysmal atrial fibrillation

ObjectivesCurrent recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation.MethodsPatients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol.ResultsWe analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation (P < 0.05). Cryo-ablation using nitrous oxide (N20) or argon (Ar) gas as cooling agents was similarly effective (P = NS).ConclusionsThe effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.

The Value of Adjunctive Left Atrial Posterior Wall Isolation on Clinical Outcomes in Atrial Fibrillation Patients: A Systematic Review and Meta-Analysis.

Although pulmonary vein isolation (PVI) remains the mainstream way of atrial fibrillation (AF) ablation. The left atrial posterior wall (LAPW) may contributes to the development of AF as an arrhythmogenic substrate. The efficacy of additional left atrial posterior wall isolation (LAPWI) beyond PVI is in AF patients remains undefined. This study explored the influence of posterior wall isolation (PWI) on clinical outcomes in AF patients. PubMed, EMBASE, and Cochrane Library databases were searched for studies comparing the outcomes of AF with and without PWI. The efficacy outcomes were recurrence of all atrial arrhythmia (AA), atrial fibrillation (AF), and atrial flutter (AFL)/atrial tachycardia (AT). The safety outcomes were mainly focused on procedural adverse events. A total of 16 studies (7 randomized controlled trials (RCTs), 3 prospective studies and 6 retrospective analyses) with 3340 AF patients were enrolled (1550 patients in PVI with PWI group and 1790 in PVI alone group). 12 studies included persistent atrial fibrillation patients, 3 studies with paroxysmal AF patients and 1 study with paroxysmal AF and persistent AF concurrently. Mean follow-up period was 16.56 months. In AF patients, adjunctive PWI obviously reduced the recurrence of all atrial arrhythmias (risk ratio (RR) 0.78 [95% CI 0.64-0.95], = 79%, p = 0.01) and the recurrence of AF (RR 0.68 [95% CI 0.53-0.88], = 75%, p = 0.004); Meanwhile, additional PWI left no impact substantially on lower recurrence of AFL/AT (RR 1.23 [95% CI 0.94-1.60], = 49%, p = 0.12). The results seemed to be no significant differences in occurrence rate of procedural complications between the PVI only and PWI+PVI (RR 1.19 [95% CI 0.80-1.79], = 0%, p = 0.39). In subgroup analyses, the benefit of adjunctive PWI compared with PVI only was more distinct in persistent AF group and cryoballoon ablation group. Notably, adjunctive PWI with radiofrequency ablation may induce a slight increase of recurrent AFL/AT compared with PVI only (RR 1.56 [95% CI 1.02-2.39], = 30%, p = 0.04). Compared with PVI alone, additional PWI to PVI appeared to be associated with decreased recurrence of AF and atrial arrhythmias without an increased occurrence of procedural complications, especially in persistent AF patients. Cryoballoon ablation seemed more suitable for PWI compared with radiofrequency ablation. More RCTs are needed to verify the conclusion.

Laser catheter ablation of atrial zones with ganglionated plexi: impact on atrial fibrillation inducibility and the risk of esophageal damage in experimental settings

Aim. To study the potential applicability of transcatheter laser ablation for the destruction of atrial ganglionated plexi (GP) zones and the safety of this technique in relation to inadvertent esophageal damage.Methods. This was a two-stage investigation: (1) ex vivo experiments: the risk of esophageal damage during ablation on the dorsal (posterior) left atrial (LA) wall was assessed; three swine organ complexes were used, which included the heart, lungs and esophagus; (2) in vivo experiments assessing the effects of laser catheter ablation of GP zones on the inducibility of atrial fibrillation (AF) and changes in atrial effective refractory period - included 13 landrace pigs (average weight 38.8±1.2 kg).Ex vivo: laser catheter ablations were performed from the endocardial surface of the LA towards the esophagus with a power of 15 watts of varying duration; ablation was performed under thermal scanning of the LA and esophagus; then a macroscopic examination of the myocardial and esophageal walls was performed.In vivo: before and after catheter laser ablation (15 W) of the GP zones in the right atrium and atrial septum, atrial ERP was assessed with programmed stimulation, and AF induction with high-frequency (33 Hz, 2 min) stimulation was evaluated. At the end of the experiment, the animals were euthanized, and the heart and lungs were collected in a single unit.Results. Ex vivo experiments: in two cases, damage to the endocardium of the LA was detected at an exposure time of 30 s. Damage to the esophagus was observed with a longer exposure time (&gt; 30 seconds) with a 11.3-15.4°C increase in temperature. In the in vivo experiments, 78 laser applications (6±1 in one swine) were delivered to the posterior wall of the right atrium and atrial septum. Atrial effective refractory period was not altered after ablation (183±20 ms vs 186±18 ms, P=0.99). At the baseline, AF was induced in 12 out of 13 animals (92%). After ablation, AF was induced in 7 animals (54%) (P=0.03). There was a trend toward a decrease in the duration of AF after laser ablation of GP zones (18 [5; 141] vs. 2 [0; 14] s after ablation, P=0.06). Transmural damage was observed in 46% of the hearts. No damage to extra-cardiac structures was detected.Conclusion. Ex vivo, laser ablation on the dorsal (posterior) wall of the LA with a power of 15 W and duration &lt;30 s does not lead to visible damage to the esophagus. Laser ablation of atrial GP zones is feasible and reduces the inducibility of AF. No change in atrial effective refractory period is detected following GP zones ablation, when performed from the right atrium.