Pulmonary Vein Antrum Isolation Research Articles

Cardiac magnetic resonance for early atrial lesion visualization post atrial fibrillation radiofrequency catheter ablation.

Incomplete atrial lesions resulting in pulmonary vein-left atrium reconnection after pulmonary vein antrum isolation (PVAI), are related to atrial fibrillation (AF) recurrence. Unfortunately, during the PVAI procedure, fluoroscopy and electroanatomic mapping cannot accurately determine the location and size of the ablation lesions in the atrial wall and this can result in incomplete PVAI lesions (PVAI-L) after radiofrequency catheter ablation (RFCA). We seek to evaluate whether cardiac magnetic resonance (CMR), immediately after RFCA of AF, can identify PVAI-L by characterizing the left atrial tissue. Ten patients (63.1 ± 5.7 years old, 80% male) receiving a RFCA for paroxysmal AF underwent a CMR before (<1 week) and after (<1 h) the PVAI. Two-dimensional dark-blood T2-weighted short tau inversion recovery (DB-STIR), Three-dimensional inversion-recovery prepared long inversion time (3D-TWILITE) and three-dimensional late gadolinium enhancement (3D-LGE) images were performed to visualize PVAI-L. The PVAI-L was visible in 10 patients (100%) using 3D-TWILITE and 3D-LGE. Conversely, On DB-STIR, the ablation core of the PAVI-L could not be identified because of a diffuse high signal of the atrial wall post-PVAI. Microvascular obstruction was identified in 7 (70%) patients using 3D-LGE. CMR can visualize PVAI-L immediately after the RFCA of AF even without the use of contrast agents. Future studies are needed to understand if the use of CMR for PVAI-L detection after RFCA can improve the results of ablation procedures.

Risk of complications in patients undergoing pulmonary vein antrum isolation: a single centre experience

Abstract Background Pulmonary vein antrum isolation (PVAI) is the gold standard approach to treat symptomatic atrial fibrillation (AF) refractory to medical therapy. While PVAI may result in a number of potential complications, there is a growing body of literature supporting safety of same day discharge post-PVAI. Purpose To retrospectively evaluate the incidence of post-procedure acute adverse events (AE), and elucidate factors associated with increased risk of such complications in patients undergoing PVAI. Methods Patients underwent PVAI between 2004-2021 at a tertiary care centre, and were followed-up at 3, 6 and 12 months post-PVAI. All procedures were performed utilizing intra-cardiac echocardiography. Baseline characteristics of patients who experienced acute AE were compared with those in patients who did not. Univariate and multivariate logistic regression models adjusted for age, sex, type of AF, left atrial size, and comorbidities were employed to evaluate risk factors for acute AE. Results 2829 patients (mean age: 61.5±10.4 years, 33.7% female, 64.1% paroxysmal AF) were included in this study. Overall incidence of acute AE was 92 (3.3%), which included: 60 (2.1%) patients with access site hematoma, 20 (0.7%) patients with hematoma requiring treatment, and 12 (0.4%) patients with cardiac tamponade. Other complications included: 5 (0.18%) strokes or transient ischemic attacks (TIA), 3 (0.10%) esophageal fistulas, and 1 (0.03%) phrenic nerve injury. Females (4.2% vs 2%, P=0.001), patients older than 75 years (3.3% vs 2.7%, P=0.8), non-paroxysmal AF (3.4% vs 2.4%, P=0.1), body mass index ≥ 35 kg/m2 (3.6% vs 2.7%, p=0.04), those with an implanted device (6.7% vs 2.3%, p=0.004), and sinus node dysfunction (SND) (6.6% vs 2.5%, p=0.001) had a greater rate of acute AEs. Patients with comorbidities, including hypertension (3.4% vs 2%, P=0.04), Type 2 diabetes ( 3.2% vs 2.7%, p=0.7), congestive heart failure (5.6% vs 2.5%, P=0.008), and coronary artery disease (3.9% vs 2.6%, p=0.1) also manifested higher rate of acute AE. In the multivariate logistic regression model, female sex (OR= 2.5 [1.4, 4.4]), CHF (OR= 2.6 [1.3, 4.9]) and SND (OR=2.6 [1.1, 5.5] were associated with increased AE risk when adjusted for age, AF type, and other comorbidities. Conclusion In the multivariate model, female sex, a history of congestive heart failure, and SND were independently associated with a greater risk of AE following PVAI.

Early lesion visualization after catheter ablation for atrial fibrillation: rationale and preliminary results of the CALAMARI study

Abstract Funding Acknowledgements Type of funding sources: None. Background Incomplete atrial lesion is related to high atrial fibrillation (AF) recurrence after Pulmonary vein antrum isolation (PVAI). Objectives The CALAMARI study is a single-center, prospective, observational study with a longitudinal design. The primary aim is to assess PVAI lesion and its development over time using cardiovascular magnetic resonance (CMR). The secondary objective is to identify possible predictors of AF recurrence. Methods 96 consecutive patients undergoing PVAI for paroxysmal AF will undergo four sequential CMR: 1) pre-PVAI CMR 2) post-PVAI CMR, immediately after the ablation 3) CMR one-day or one-week post-PVAI 4) CMR 3-months post-PVAI. Dark-blood short-inversion-time recovery (DB-STIR) will identify oedema. Pre- and post-contrast prepped inversion-recovery with long inversion time (IR-prep) and three-dimensional late gadolinium enhancement (3D-LGE) images will be used to visualize atrial lesion (AL). Qualitative and quantitative assessments of AL will be performed. Patients will be followed-up for 2 years to identify AF recurrence. Preliminary results Ten patients (63.1±5.7 years old, 80% male) completed a pre-PVAI CMR and a post-PVAI-CMR. The AL post-PVAI was visible in 9 patients (90%) using post-contrast IR-prep sequences and in 6 patients (60%) using pre-contrast IR-prep and 3D-LGE. Microvascular obstruction was identified in 7 (70%) patients using IR-prep-post-contrast. On DB-STIR, edema was visualized in all patients with a significant increase in the left atrium wall thickening in CMR post-PVAI vs. pre-PVAI CMR (6.4±2.9 vs. 3.4±1.5, p = 0.09). Conclusion Post-PVAI AL visualization with CMR is feasible in most patients. The CALAMARI study will better understand the AL modifications over time.

Personalized pulmonary vein antrum isolation guided by left atrial wall thickness for persistent atrial fibrillation.

Pulmonary vein (PV) antrum isolation proved to be effective for treating persistent atrial fibrillation (PeAF). We sought to investigate the results of a personalized approach aimed at adapting the ablation index (AI) to the local left atrial wall thickness (LAWT) in a cohort of consecutive patients with PeAF. Consecutive patients referred for PeAF first ablation were prospectively enrolled. The LAWT three-dimensional maps were obtained from pre-procedure multidetector computed tomography and integrated into the navigation system. Ablation index was titrated according to the local LAWT, and the ablation line was personalized to avoid the thickest regions while encircling the PV antrum. A total of 121 patients (69.4% male, age 64.5 ± 9.5 years) were included. Procedure time was 57 min (IQR 50-67), fluoroscopy time was 43 s (IQR 20-71), and radiofrequency (RF) time was 16.5 min (IQR 14.3-18.4). The median AI tailored to the local LAWT was 387 (IQR 360-410) for the anterior wall and 335 (IQR 300-375) for the posterior wall. First-pass PV antrum isolation was obtained in 103 (85%) of the right PVs and 103 (85%) of the left PVs. Median LAWT values were higher for PVs without first-pass isolation as compared to the whole cohort (P = 0.02 for left PVs and P = 0.03 for right PVs). Recurrence-free survival was 79% at 12 month follow-up. In this prospective study, LAWT-guided PV antrum isolation for PeAF was effective and efficient, requiring low procedure, fluoroscopy, and RF time. A randomized trial comparing the LAWT-guided ablation with the standard of practice is in progress (ClinicalTrials.gov, NCT05396534).

Interatrial conduction time is associated with left atrial low voltage area and predicts the recurrence after single atrial fibrillation ablation.

Interatrial conduction time (IACT) prolongs in fibrotic left atrium. We tested the hypothesis that IACT is related to left atrial low voltage area (LVA) and predicts the recurrence after single atrial fibrillation (AF) ablation. One hundred sixty-four consecutive AF patients (79 non-paroxysmal) who underwent initial ablation in our institute were analyzed. IACT and LVA were defined as interval from the onset of P-wave to the basal left atrial appendage (P-LAA) activation, and area with bipolar electrogram < 0.5mV covering over 5% of the total left atrial surface area during sinus rhythm, respectively. Pulmonary vein antrum isolation, non-PV foci ablation, and atrial tachycardia (AT) ablation were performed without substrate modification. LVA was frequently identified in patients with prolonged P-LAA ≥ 84 ms (n = 28) compared with patients with P-LAA < 84 ms (n = 136). Patients with P-LAA ≥ 84 ms were older (71 ± 10 vs. 65 ± 10 years, p = .0061), and had more frequent non-paroxysmal AF (75% vs. 43%, p = .0018), larger left atrial diameter (43.5 ± 4.5 vs. 39.3 ± 5.7 mm, p = .0003), and higher E/e' ratio (14.4 ± 6.5 vs. 10.5 ± 3.7, p < .0001) compared with P-LAA < 84 ms patients. After a mean follow-up period of 665 ± 153 days, Kaplan-Meier curve analysis showed that AF/AT recurrences was more frequently observed in patients with prolonged P-LAA (Log-rank p = .0001). Additionally, univariate analysis revealed that P-LAA prolongation (OR=1.055 per 1ms, 95% CI: 1.028-1.087, p < .0001) and the existence of LVA (OR=5.000, 95% CI: 1.653-14.485 p = .0053) were predictors of AF/AT recurrences after single AF ablation. Our results suggested that prolonged IACT as measured by P-LAA was associated with LVA and predicts AT/AF recurrence after single AF ablation.

Effect of catheter ablation for atrial fibrillation on left and right atrial function

Aim. To evaluate the effect of catheter ablation on left (LA) and right atria (RA) function in patients with atrial fibrillation.Material and methods. The study included 28 patients (14 men and 14 women) aged 33 to 72 years (mean age, 57,7±9,9 years) with paroxysmal (n=23) and persistent AF (n=5). All patients underwent radiofrequency ablation (RFA) with pulmonary vein antrum isolation. Before ablation and 3 days after, transthoracic twodimensional echocardiography was performed in sinus rhythm with an assessment of LA reservoir, conduit and booster pump function and RA peak longitudinal strain.Results. In the studied patients, a significant decrease in the reservoir, conduit and booster pump function of the LA was revealed after RFA, while there was no significant change in RA peak longitudinal strain after catheter ablation. LA reservoir, conduit and booster pump function decreased by 6,45% (p&lt;0,001), 3,59% (p&lt;0,001), 2,85% (p&lt;0,001), respectively, while RA peak longitudinal strain increased by 0,73% (p=0,43).Conclusion. Catheter ablation has a significant damaging effect on the LA tissue, inhibiting the reservoir, pumping and pipeline functions. At the same time, the contractility of the PP in the early postoperative period improves, but not significantly.

Epicardial Connections After a Conventional Pulmonary Vein Antrum Isolation in Patients With Atrial Fibrillation.

The existence of epicardial connection(s) (ECs) between the pulmonary veins (PVs) and atrium may hinder establishing a complete PV antrum isolation (AI) (PVAI) in patients with atrial fibrillation (AF). Thus, the purpose of this study was to determine the prevalence and location of ECs inside the conventional PVAI lines.Methods and Results: Three-hundred consecutive patients with non-valvular AF were evaluated. This study revealed that: (1) the prevalence of patients with ECs and the number of ECs per patient between the PVs and atrium became significantly greater, respectively, in accordance with the progression of paroxysmal to long-lasting AF and left atrial enlargement; (2) some ECs were located at sites far distal to the PVAI lines; (3) 25% of ECs could be detected only by high-density mapping catheters, but not by conventional circular mapping catheters; (4) a B-type natriuretic peptide (BNP) level of 176.6pg/mL and left atrial volume (LAV) of 129.0 mL may be important predictors of the presence of ECs; and (5) the rate of conduction of ECs from the right PVs was dominantly to the atrium and His-bundle, and that from the left PVs to the coronary sinus was most dominant. The PVAI may not be completed by using only a conventional PVAI method, and additional EC ablation inside the PVAI lines detected using high-density mapping may be able to achieve a more complete PVAI.

Evaluation of Safety and Effectiveness of Catheter Ablation of Atrial Fibrillation in Patients Aged ≥80 Years

The prevalence and incidence of atrial fibrillation (AF) significantly increase with age. Catheter ablation is already recommended in the guidelines for this selected elderly population. This study aimed to explore the safety and effectiveness of AF catheter ablation in patients aged ≥80 years. The data were based on the China-AF study. Patients with AF aged ≥80 years who received catheter ablation from August 2011 to December 2020 were selected. Catheter ablation included bilateral circumferential pulmonary vein antrum isolation with or without additional linear ablation. Patients were followed up every 6 months. Arrhythmia-free curves were generated using Kaplan-Meier analysis. Cox proportional hazards regression models were used to analyse the predictors for post-ablation recurrence. A total of 270 patients were included in the study. Many patients had comorbidities: 73.7% had hypertension and 29.3% had diabetes mellitus. All patients achieved successful bilateral circumferential pulmonary vein antrum isolation. Total complications were noted in nine of 270 (3.3%) patients and nine of 286 (3.1%) ablation procedures. After the first ablation procedure, 74% of the whole cohort-78% patients with paroxysmal AF, and 66% patients with persistent AF - were free from atrial tachyarrhythmia at follow-up to 12 months. Patients with persistent AF, longer AF duration, and history of ischaemic stroke were more likely to have AF recurrence. Patients with AF aged ≥80 years, although with many comorbidities, had low complication rates and favourable outcomes after catheter ablation. Catheter ablation was a safe and effective treatment to achieve sinus rhythm in the selected elderly patients.

471 Arrhythmia-free survival in early-persistent atrial fibrillation patients undergoing radiofrequency catheter ablation

Abstract Aims Despite advances in success rate of paroxysmal atrial fibrillation (PAF) ablation, outcomes of radiofrequency catheter ablation (RFCA) in patients with persistent AF are highly variable. Early persistent AF (EPsAF) is defined as AF that is sustained beyond 7 days but is less than 3 months in duration. Arrhythmia-free survival data after RFCA in this specific population are still limited. We sought to report the outcomes of RFCA in the subgroup of patients with EPsAF, compared to those with PAF and with ‘late’ persistent AF (LPsAF) lasting between 3 and 12 months. Methods and results Data from 1143 consecutive AF patients receiving their first RFCA were prospectively collected. Patients with EPsAF (n = 190) were compared with PAF (n = 531) and LPsAF (n = 422) patients. All patients received pulmonary vein antrum isolation + posterior wall and sustained non-pulmonary vein (PV) trigger ablation. Non-sustained non-PV triggers were ablated based on operator discretion. Non-PV triggers were defined as sites of firing leading to sustained (&amp;gt;30 s) or non-sustained arrhythmias (&amp;lt;30 s, including premature atrial contractions ≥10 beats/min) with earliest activation outside the PVs. Mean age of the population was 64 ± 11 years. Female patients were more in PAF group (39%) compared to EPsAF (26%) and LPsAF (28%) (P &amp;lt; 0.001). There was no difference in other clinical characteristics among populations. Non-PV triggers were detected more in EPsAF [127 (66.8%)], and LPsAF [296 (70.1%)] patients compared to PAF [185 (34.8%)] (P &amp;lt; 0.001).One-year arrhythmia-free survival rate after a single procedure was 75.0% (398), 74.2% (141), and 64.5% (272) in PAF, EPsAF, and LPsAF, respectively. Success rate was significantly higher in PAF {[HR: 0.67 (0.53, 0.84), P = 0.001] and EPsAF [HR: 0.67 (0.49, 0.93)], P = 0.015} compared to LPsAF. Conclusions In patients with EPsAF, RFCA may result in significantly better freedom from atrial arrhythmias, compared to LPsAF. In this cohort, ablation might be reasonable as first line approach to improve outcomes and prevent AF progression.

Targeting non-pulmonary vein triggers in persistent atrial fibrillation: results from a prospective, multicentre, observational registry.

We evaluated the efficacy of an ablation strategy empirically targeting pulmonary veins (PVs) and posterior wall (PW) and the prevalence and clinical impact of extrapulmonary trigger inducibility and ablation in a large cohort of patients with persistent atrial fibrillation (PerAF). A total of 1803 PerAF patients were prospectively enrolled. All patients underwent pulmonary vein antrum isolation (PVAI) extended to the entire PW. A standardized protocol was performed to confirm persistent PVAI and elicit any triggers originating from non-PV sites. All non-PV triggers initiating sustained atrial tachyarrhythmias were ablated. Ablation of non-PV sites triggering non-sustained runs (<30 s) of atrial tachyarrhythmias or promoting frequent premature atrial complexes (≥10/min) was left to operator's discretion. Overall, 1319 (73.2%) patients had documented triggers from non-PV areas. After 17.4 ± 8.5 months of follow-up, the cumulative freedom from atrial tachyarrhythmias among patients without inducible non-PV triggers (n = 484) was 70.2%. Patients with ablation of induced non-PV triggers had a significantly higher arrhythmia control than those whose triggers were not ablated (67.9% vs. 39.4%, respectively; P < 0.001). After adjusting for clinically relevant variables, patients in whom non-PV triggers were documented but not ablated had an increased risk of arrhythmia relapse (hazard ratio: 2.39; 95% confidence interval: 2.01-2.83; P < 0.001). Pulmonary vein antrum isolation extended to the entire PW might provide acceptable long-term arrhythmia-free survival in PerAF patients without inducible non-PV triggers. In our population of PerAF patients, non-PV triggers could be elicited in ∼70% of PerAF patients and their elimination significantly improved outcomes.

B-PO04-114 EFFECT OF SINUS NODE DYSFUNCTION ON RECURRENCE OF ATRIAL FIBRILLATION IN PATIENTS UNDERGOING PULMONARY VEIN ANTRUM ISOLATION

Atrial Fibrillation (AF) is the most common arrhythmia. Patients with AF refractory to medical therapy undergo pulmonary vein antrum isolation (PVAI). Long term rhythm control post procedure remains a challenge. To elucidate the role of baseline sinus node dysfunction (SND) in recurrence of AF post-PVAI. Baseline, and follow-up data for patients with paroxysmal AF (PAF) undergoing PVAI at a single tertiary care center between 2004-2019 was collected. ECG and holter monitoring were done at 1, 3, 6, and 12 months post procedure. Episodes recorded during the blanking period (<3 months) were considered early (ER), while those occurring after were noted as late recurrence (LR). To assess the impact of SND, a multivariate logistic regression model was constructed. Kaplan-Meier analysis was done to examine the overall AF-free survival in each group (SND vs No-SND). Overall, 1,529 consecutive PAF patients (female: 38.2%, mean age: 60.6±10.7 years, mean follow-up time: 22.3±17.4 months, SND: 7.8%) were included in the study. Rate of ER and LR was significantly higher in patients with SND (ER: 51 (44%) vs 400(30%), P=0.002 and LR: 79 (68.1%) vs 524 (41%), P<0.001). After controlling for age, sex, diabetes, hypertension, left atrial size, and ejection fraction, SND emerged as the independent predictor of both early and late AF recurrence (ER: OR=1.8 (1.2-2.7)) and LR: OR=3.0 (1.9-4.5)). Similarly, patients with SND had significantly lower 1-year AF-Free Survival compared to those without (ER: 57% vs 70%, P<0.002 and LR: 52.5% vs 70.1%, <0.001). Sinus Node Dysfunction is an important prognostic marker for PVAI success, and AF recurrence post ablation.

B-AB21-04 EFFECTIVENESS OF ETHANOL INFUSION INTO THE VEIN OF MARSHALL COMBINED WITH A FIXED ANATOMICAL ABLATION STRATEGY (THE ‘UPGRADED 2C3L’ APPROACH) FOR CATHETER ABLATION OF PERSISTENT ATRIAL FIBRILLATION

Linear ablation in addition to pulmonary vein antrum isolation (PVAI) cannot improve success rate for persistent atrial fibrillation (PeAF), due to incomplete block of ablation lines, especially in the mitral isthmus (MI). Ethanol infusion has been reported to facilitate MI ablation and PVAI.

Effectiveness of ethanol infusion into the vein of Marshall combined with a fixed anatomical ablation strategy (the "upgraded 2C3L" approach) for catheter ablation of persistent atrial fibrillation.

Linear ablation in addition to pulmonary vein antrum isolation (PVAI) has failed to improve the success rate for persistent atrial fibrillation (PeAF), due to incomplete block of ablation lines, especially in the mitral isthmus (MI). The study enrolled 191 patients (66 in group 1 and 125 in group 2). In group 1, ethanol infusion into the vein of Marshallwas firstperformed, followed by radiofrequency (RF) applications targeting bilateral PVAI and bidirectional block in the roofline, cavotricuspid isthmus, and MI. In group 2, PVAI and the three linear ablations were completed using only RF energy. MI block was achieved in 63 (95.5%) and 101 (80.8%) patients in groups 1 and 2, respectively (p = .006). Patients in group 1 had shorter ablation time for left pulmonary vein antrum (8.15vs. 12.59 min, p < .001) and MI (7.0vs. 11.8 min, p < .001) and required less cardioversion (50 [78.5%] vs. 113 [90.4%], p = .007). During the 12-month follow-up, 58 (87.9%) patients were free from atrial fibrillation/atrial tachycardia in group 1 compared with 81 (64.8%) in group 2 (p < .001). In multivariate cox regression, the "upgraded 2C3L" procedure is associated with a lower recurrence rate (hazard ratio = 0.27, 95% confidence interval = 0.12-0.59). Compared with the conventional "2C3L" approach, the "upgraded 2C3L" approach has higher effectiveness for ablation of PeAF.

Importance of the length of the myocardial sleeve in the superior vena cava in patients with atrial fibrillation.

BackgroundPulmonary vein (PV) antrum isolation (PVAI) has proven to be a useful strategy for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) worldwide. However, non‐PV foci, especially from the superior vena cava (SVC), play an important role in initiating and maintaining AF.MethodsIn all, 427 consecutive patients with non‐valvular AF who were admitted to our hospitals to undergo RFCA of AF using an EnSite™ system were evaluated. The length from the top of the sinus node to the top of the myocardial sleeve of SVC (L‐SVC), longer and shorter diameter of SVC of 1 cm above of junction of right atrium and SVC, and local activation time (LAT) of SVC were measured. Then, the SVC firing was evaluated by an intravenous administration of isoproterenol and adenosine triphosphate.ResultsL‐SVC, longer and shorter diameter of SVC, and LAT of SVC were significantly longer in the SVC firing group than non‐SVC firing group (P < .05). Moreover, in accordance with the L‐SVC, the frequency of the SVC firing significantly increased (P < .001). A univariate analysis and multivariate statistical analysis revealed that L‐SVC longer than 37.0 mm (odds ratio 6.39) and longer diameter of SVC (odds ratio 6.78) were independent risk factors for SVC firing in patients with AF who underwent RFCA of AF.ConclusionsIn view of these findings, L‐SVC longer than 37.0 mm longer diameter SVC longer than 17.0 mm may be one of the important predictors of SVC firing in patients with AF.

Concealed Connection between Pulmonary Veins and Atrium after Pulmonary Vein Antrum Isolation in Patients with Atrial Fibrillation (COCO-AF Trial）

Concealed Connection between Pulmonary Veins and Atrium after Pulmonary Vein Antrum Isolation in Patients with Atrial Fibrillation (COCO-AF Trial）

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

SINGLE PROCEDURE SUCCESS RATE OF RADIOFREQUENCY CATHETER ABLATION OF PERSISTENT ATRIAL FIBRILLATION RESULTS FROM A PROSPECTIVE, MULTICENTRE, OBSERVATIONAL REGISTRY

We prospectively evaluated the electrophysiological features and ablation outcomes in a large cohort of Persistent AF patients. All patients (n=1803) underwent pulmonary vein antrum isolation (PVAI) extended to the entire posterior wall (PW). A standardized protocol was performed to elicit any AF

P4761Impact of focal ablation versus isolation of the coronary sinus in patients undergoing repeat radiofrequency catheter ablation of persistent atrial fibrillation

Abstract Introduction Non-pulmonary vein (PV) triggers originating from the coronary sinus (CS) are a common finding in atrial fibrillation (AF) patients. To date, no studies have investigated the clinical impact of focal ablation versus isolation of the CS in patients presenting triggers from this area. Purpose This study analyzed the effectiveness of two different approaches for CS ablation (total isolation vs focal ablation) in persistent AF patients undergoing repeat AF ablation. Methods Consecutive persistent AF patients undergoing repeat ablation were enrolled in this prospective analysis. All patients had triggers from the CS documented during high-dose isoproterenol. Pulmonary vein antrum isolation (PVAI) extended to the posterior wall (PW) plus superior vena cava (SVC) isolation was performed in all patients at first procedure. At repeat procedure, PV, PW, and SVC were re-isolated, if needed. Focal ablation or isolation of the CS was performed based on operator's choice either at first and/or repeat procedure, along with ablation of other non-PV triggers. Patients with triggers from left atrial appendage were excluded from the study. Results Overall, 628 consecutive patients (73.4% male, age 66.9±9.0 years) were enrolled. On the basis of the CS ablation strategy, patients were categorized into two groups: Group I received CS isolation (n=389) and Group II received CS focal ablation (n=239). Major clinical characteristics were not different between groups. PV reconnection was documented in 55 (14.1%) patients of Group I and 33 (13.8%) of Group II. The incidence of procedure-related complications was similar between the two groups (10 [2.6%] in Group I vs 6 [2.5%] in Group II; p=0.9). After a follow-up of 18±8 months, 276 (71%) patients in Group I and 115 (48%) in Group II remained arrhythmia-free (p&lt;0.001, figure.1). After adjusting for age, gender and clinically relevant variables, CS isolation was associated with a significantly higher arrhythmia-free survival rate (HR: 0.47; 95% CI: 0.37–0.61, p-value&lt;0.001). Conclusions In patients with documented triggers from the CS undergoing repeat ablation of persistent AF, isolation rather than focal ablation of the CS significantly increased freedom from atrial tachyarrhythmias in the long term.

Translational anatomy of the left atrium and esophagus as relevant to the pulmonary vein antral isolation for atrial fibrillation.

Pulmonary vein antrum isolation by radiofrequency ablation has become a preferred treatment for atrial fibrillation. The aim of our research is to study the anatomy of the PVantrum and its related structures with special emphasis on the esophageal relation to the various components of the antrum, as thermal injury is a common complication. Mediastinal contents were extracted "en bloc" from 30 human formalin fixed adult cadavers to study the posterior wall of the left atrium along with the esophagus. The pulmonary antrum was measured. Each pulmonary ostium was assessed for circumference and muscle thickness. The esophagus was related to the left superior ostium in 90% of cases. The esophagus was traced on the atrial wall in each case; the distance from endocardium was measured at five equidistant lines. AV node distance from the right inferior pulmonary vein was 5cm. The atrioventricular part of the membranous septum measured 4.2mm. For antral isolation the ablation lines are about 3cm superior, 3.5cm inferior and about 1cm apart. The esophagus is ~ 12mm away at the superior and ~ 7mm away at the inferior ablation line. On the left ablation line this distance would diminish from 15 to 7mm. The pulmonary ostial circumference is ~ 5cm with muscle thickness varying from 0.7 to 4mm. The left ostia need more ablative power as they have a 60% (1mm) thicker muscle coat. Care should be taken while ablating round the left superior ostium as the esophagus lies 1-3cm behind it in 90% of the cases.

NON-PULMONARY VEIN TRIGGER ABLATION IMPROVES THE SINGLE-PROCEDURE SUCCESS RATE OF CATHETER ABLATION IN PERSISTENT ATRIAL FIBRILLATION: RESULTS FROM A LARGE PROSPECTIVE MULTICENTRE EXPERIENCE

Catheter ablation of persistent atrial fibrillation (PerAF) has a lower success rate when compared to paroxysmal AF. It is still debated in the literature whether pulmonary vein antrum isolation (PVAI) is sufficient to achieve long-term freedom from atrial tachyarrhythmias in PerAF patients.