Search

Background/Objectives: Pulmonary vein isolation (PVI) using radiofrequency catheter ablation with contact force (CF)-sensing technology has improved long-term outcomes in patients with atrial fibrillation. This prospective randomized study aimed to assess the efficacy and safety of CF-sensing technology for additional left atrial (LA) linear ablation of persistent AF (PerAF). Methods: After PVI, anteromitral (AM) line and roof line ablation were performed using a CF-sensing catheter. Patients were randomly assigned to either the CF-sensing (CFS) group or the CF-blind control (Blind) group. The primary endpoint was atrial arrhythmia recurrence. LA late gadolinium enhancement (LA-LGE) MRI was conducted at baseline and 1-year follow-up for long-term lesion evaluation. Results: A total of 62 patients with drug-refractory PerAF were enrolled (mean age: 58 ± 10 years; 77% male). The success rates of AM and roof line block were 97% and 100% in the CFS group (n = 33) and 93% and 90% in the Blind group (n = 29). The time to achieve block was reduced in the CFS group (AM: 36 ± 22 vs. 48 ± 28 min, p = 0.068; roof: 19 ± 14 vs. 27 ± 15 min, p = 0.031). The maximum CF for safety endpoints was significantly lower in the CFS group (AM: 42 vs. 69 g, p < 0.001; roof: 33 vs. 49 g, p = 0.003). Full linear LA-LGE formation on 1-year MRI did not differ significantly between the groups (AM: 17 vs. 36%; roof; 29 vs. 24%, both p = NS). Kaplan–Meier estimates of AF/AT-free survival after ablation procedures were 63.6% in the CFS group and 58.6% in the Blind group (log-rank p = 0.837). Conclusions: In patients with PerAF, additional LA linear ablation following PVI using CF-sensing technology improved procedural safety and reduced the time needed to achieve conduction block. However, it did not significantly influence clinical outcomes or the formation of permanent full linear lesions. [ABSTRACT FROM AUTHOR]

Aim: To explore the safety and efficacy of a novel strategy (bi-atrial linear catheter ablation guided by electrophysiological mapping) for persistent atrial fibrillation (PeAF) treatment. Methods: 83 patients with PeAF were enrolled for evaluation of ablation strategy. 43 patients were subjected to pulmonary vein isolation (PVI) strategy (PVI group). 40 patients were subjected to bi-atrial linear ablation strategy guided by electrophysiological mapping (PVI, left atrial BOX ablation, coronary sinus endocardial linear ablation, tailored left atrial anterior wall linear ablation, mitral isthmus linear ablation with necessary ethanol infusion into the vein of Marshall, right atrial posterior wall linear ablation and cavo-tricuspid isthmus ablation) (linear ablation group). Patients were followed up every 3 months. Results: During a median follow-up of 12 (4–16) months, freedom from atrial fibrillation/atrial tachycardia recurrence was 87.5% in the linear ablation group and 65.1% in the PVI group (P < 0.01). A Cox regression multivariate analysis revealed that ablation strategy group (tailored bi-atrial linear ablation) (HR 0.33, 95% CI 0.12–0.91, P = 0.03) was the only independent predictor of recurrence. Conclusion: Tailored bi-atrial linear ablation strategy guided by electrophysiological mapping resulted in improved outcomes without compromising safety for patients with PeAF. [ABSTRACT FROM AUTHOR]

Abstract Aim To explore the safety and efficacy of a novel strategy (bi-atrial linear catheter ablation guided by electrophysiological mapping) for persistent atrial fibrillation (PeAF) treatment. Methods 83 patients with PeAF were enrolled for evaluation of ablation strategy. 43 patients were subjected to pulmonary vein isolation (PVI) strategy (PVI group). 40 patients were subjected to bi-atrial linear ablation strategy guided by electrophysiological mapping (PVI, left atrial BOX ablation, coronary sinus endocardial linear ablation, tailored left atrial anterior wall linear ablation, mitral isthmus linear ablation with necessary ethanol infusion into the vein of Marshall, right atrial posterior wall linear ablation and cavo-tricuspid isthmus ablation) (linear ablation group). Patients were followed up every 3 months. Results During a median follow-up of 12 (4–16) months, freedom from atrial fibrillation/atrial tachycardia recurrence was 87.5% in the linear ablation group and 65.1% in the PVI group (P

Background: Maintaining an adequate temperature at the target site is essential for effective ablation. We hypothesized that a tissue temperature‐controlled (T‐Con) catheter for cavotricuspid isthmus (CTI) ablation could improve the procedural ablation parameters. Purpose: To evaluate the efficacy and safety of the T‐Con (DiamondTemp™) catheter for CTI ablation compared with non‐irrigation (Non‐Irri) and irrigation (Irri) catheters. Methods: We analyzed 150 patients who underwent prophylactic CTI ablation combined with pulmonary vein isolation. The Non‐Irri, Irri, and T‐Con catheter groups comprised 50 patients each, and the ablation procedural parameters and complications were compared between these groups. Results: There were no significant differences in clinical background characteristics among the three groups. The Kruskal–Wallis and post hoc tests demonstrated that the T‐Con group showed the lowest total radiofrequency energy delivery time among the three groups (median [25 and 75 percentiles]: 340 [209, 357], 147 [100, 199], and 83 [61, 109] s, respectively in the Non‐Irri, Irri, and T‐Con groups; T‐Con versus Non‐Irri, p <.01; T‐Con versus Irri, p <.01). The total procedural time and acute reconnection rate in the T‐Con group (264 s and 4%, respectively) were lower than those in the Non‐Irri group (438 s and 24%) but were similar to those in the Irri group (268 s and 6%). No significant complications were observed in any group. Conclusions: The T‐Con catheter achieved a short energy delivery time and a low acute reconnection rate, indicating its potential as an alternative catheter for CTI ablation. [ABSTRACT FROM AUTHOR]

Background: Patients may develop atrial tachycardia (AT) after left atrial (LA) ablation of persistent atrial fibrillation (AF). Methods: The population consisted of 101 consecutive patients (age = 64.3 ± 8.7 years, 70 males (69%), LA = 4.6 ± 0.8 cm, ejection fraction = 48.5 ± 16%) undergoing their initial procedure for persistent AF. After pulmonary vein isolation, patients either underwent posterior LA isolation (n = 50; study group) or linear ablation at the LA roof with verification of conduction block (n = 51; control group). Results: A repeat procedure was performed in 17 (34%) and 28 (55%) patients in the study and control groups, respectively (p = 0.02). Patients in the study group were less likely to develop AT (9/50 [18%] vs. 18/51 [35%]; p = 0.02), roof-dependent (1/50 [2%] vs. 8/51 [16%]; p = 0.008), and multi-loop AT (6/50 [12%] vs. 14/51 [27%]; p = 0.03) as compared to controls. Among various factors, only posterior LA isolation was associated with a lower likelihood of AT recurrence and roof tachycardia at redo procedure (OR, 0.37; 95% CI, 0.1 to 1.00, p = 0.05, and OR, 0.1, 95% CI, 0.01 to 0.96; p < 0.05, respectively). Conclusions: In patients with persistent AF, posterior LA isolation is associated with a lower risk of a redo procedure, roof-dependent macro-reentry, and post-ablation AT in general as compared to controls who only received roof ablation. Posterior LA isolation also obviates the need for pacing maneuvers, and may be a more definitive endpoint than linear ablation at the LA roof. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation is routinely used to treat scar-related atrial tachycardia (s-AT). Conventional ablation often involves creating anatomical "lines" that transect myocardial tissue supporting reentry. This can be extensive, creating iatrogenic scar as a nidus for future reentry, and may account for arrhythmia recurrence. High-density mapping may identify "narrower isthmuses" requiring less ablation, with ripple mapping proven to be an effective approach in identifying. This trial explores whether ablation of narrower isthmuses in s-AT, defined using ripple mapping, results in greater freedom from arrhythmia recurrence compared to conventional ablation. Methods: The Ripple-AT-Plus trial (registration ClinicalTrials.gov, NCT03915691) is a prospective, multicentre, single-blinded, randomised controlled trial with 12-month follow-up. Two hundred s-AT patients will be randomised in a 1:1 fashion to either "ripple mapping-guided isthmus ablation" vs conventional ablation on the CARTO3 ConfiDENSE system (Biosense Webster). The primary outcome will compare recurrence of any atrial arrhythmia. Multicentre data will be analysed over a secure web-based cloud-storage and analysis software (CARTONETTM). Conclusion: This is the first trial that considers long-term patient outcomes post s-AT ablation, and whether targeting narrower isthmuses in the era of high density is optimal. [ABSTRACT FROM AUTHOR]

Background An optimal strategy for left atrial ablation in addition to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) has not been determined. Methods and Results We conducted an extended follow‐up of the multicenter randomized controlled EARNEST‐PVI (Efficacy of Pulmonary Vein Isolation Alone in Patients With Persistent Atrial Fibrillation) trial, which compared 12‐month rhythm outcomes in patients with persistent AF between patients randomized to a PVI‐alone strategy (n=248) or PVI‐plus strategy (n=248; PVI followed by left atrial additional ablation, including linear ablation or ablation targeting areas with complex fractionated electrograms). The present study extended the follow‐up period to 3 years after enrollment. Outcomes were compared not only between randomly allocated groups but also between on‐treatment groups categorized by actually created ablation lesions. Recurrence rate of AF or atrial tachycardia (AT) was lower in the randomly allocated to PVI‐plus group than the PVI‐alone group (29.0% versus 37.5%, P=0.036). On‐treatment analysis revealed that patients with PVI+linear ablation (n=205) demonstrated a lower AF/AT recurrence rate than those with PVI only (26.3% versus 37.8%, P=0.007). In contrast, patients with PVI+complex fractionated electrograms ablation (n=37) had an AF/AT recurrence rate comparable to that of patients with PVI only (40.5% versus 37.8%, P=0.76). At second ablation in 126 patients with AF/AT recurrence, ATs excluding common atrial flutter were more frequent in patients with PVI+linear ablation than in those with PVI only (32.6% versus 5.7%, P

Background: For patients with persistent atrial fibrillation (AF), whether linear ablation should be performed remains controversial, and the efficacy and safety for ablation index (AI)-guided high-energy linear ablation of mitral isthmus (MI) and left atrial (LA) posterior box isolation is still unclear. The aims of this study were to assess the feasibility and clinical success rate of pulmonary veins isolation (PVI) combined with linear ablation of LA roof and posterior inferior (posterior wall isolation) and MI compare with the PVI-alone method in patients of persistent AF. Methods and results: 362 consecutive persistent AF patients were enrolled from two electrophysiology centers. A total of 200 cases were in PVI-plus group and 162 cases were in PVI-alone group. The PVI-alone group received wide circumferential isolation of both ipsilateral pulmonary veins. PVI combined with linear ablation of left atrial posterior wall isolation (LAPWI)and MI were performed in the PVI-plus group. The primary study end point was the first recurrence of an atrial arrhythmia. After 24 months, freedom from the primary endpoint was achieved in 73.5% of the patients in the PVI-plus group and 62.5% in the PVI-alone group (hazard ratio = 0.62, 95% confidence interval: 0.43–0.91, log rank p = 0.012). The procedure-related complication rates were 2.5% in PVI-plus group and 1.9% in PVI-alone group (p = 0.808). Conclusion: In this study, the ablation strategy of ablation (PVI plus linear ablation of mitral isthmus and posterior box isolation) was feasible and safe for persistent AF patients. Compared with the PVI-alone method, it improved outcomes in patients with persistent AF. [ABSTRACT FROM AUTHOR]

Abstract Background The efficacy of pulmonary vein isolation (PVI) alone is not guaranteed for persistent atrial fibrillation (PeAF), and it is unclear which type of ablation approach should be applied in addition to PVI. This study aimed to compare outcomes and prognosis between empirical linear ablation and low-voltage area (LVA) ablation after PVI for PeAF. Methods We enrolled 128 patients with PeAF who were assigned to the linear ablation group (n = 64) and the LVA ablation group (n = 64) using a propensity score-matched model. After PVI and cardioversion, the patients underwent either empirical linear ablation or LVA ablation during sinus rhythm. All patients in the linear ablation group underwent both roof line and mitral valve isthmus (MVI) ablations. An electrical-guided ablation targeting LVA (

Recurrent atrial tachycardia (AT) is a common phenomenon after catheter ablation for AF, particularly in the setting of additional substrate ablation, with many studies demonstrating gap-related macro re-entrant AT (predominantly mitral and roof dependent) to be the dominant mechanism. Although multiple inducible ATs after ablation of the clinical AT are commonly described at repeat procedures, the optimal ablation strategy, and procedural endpoints are unclear in this setting. A recent randomized study addressing the question of non-inducibility as a procedural endpoint demonstrated no additional benefits to the ablation of all induced, non-clinical ATs, but it was limited by small numbers and high rates of non-inducibility. Nevertheless, once ablation of the clinical AT has been successfully performed, ensuring durable linear block and PV isolation may be sufficient for the prevention of further AT. Durable linear block, particularly at the mitral isthmus, is difficult to achieve but may be facilitated by the real-time evaluation of lesion quality and contiguity and the novel technique of vein of Marshall ethanol infusion. Large-scale, randomized trials are needed, nonetheless, to fully assess the optimal ablation strategy in the setting of recurrent AT post-AF ablation.

Extensive ablation in addition to pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) has not yielded consistent results, indicating diversity in their efficacy. Mitral regurgitation (MR) associated with AF may indicate a higher prevalence of arrhythmogenic substrate, suggesting potential benefits of extensive ablation for these patients. This post-hoc analysis of the EARNEST-PVI trial compared PVI alone versus an extensive ablation strategy (PVI-plus) in persistent AF patients, stratified by MR presence. The primary endpoint of the study was the recurrence of AF. The secondary endpoints included death, cerebral infarction, and procedure-related complications. The trial included 495 eligible patients divided into MR and non-MR groups. The MR group consisted of 192 patients (89 in the PVI-alone arm and 103 in the PVI-plus arm), while the non-MR group had 303 patients (158 in the PVI-alone arm and 145 in the PVI-plus arm). In the non-MR group, recurrence rates were similar between PVI-alone and PVI-plus arms (Log-rank P = 0.47, Hazard ratio = 0.85 [95%CI: 0.54–1.33], P = 0.472). However, in the MR group, PVI-plus was significantly more effective in preventing AF recurrence (Log-rank P = 0.0014, Hazard ratio = 0.40 [95%CI: 0.22–0.72], P = 0.0021). No significant differences were observed in secondary endpoints between the two arms. For persistent AF patients with mild or greater MR, receiving PVI-plus was superior to PVI-alone in preventing AF recurrence. Conversely, for patients without MR, the effectiveness of extensive ablation was not demonstrated. These findings suggest tailoring ablation strategies based on MR presence can lead to better outcomes in AF management. Extensive ablation for persistent atrial fibrillation patients with mitral regurgitation: insights from the EARNEST-PVI prospective randomized trial. [Display omitted] • The randomized trial: PVI-alone vs. extensive ablation strategy for persistent AF. • In patients with MR, extensive ablation strategy lowered AF recurrence rate. • In patients without MR, AF recurrence rates were similar in both ablation strategies. • Presence of MR and treatment strategy showed a significant interaction. [ABSTRACT FROM AUTHOR]

Purpose: Based on the high rate of coexisting atrial fibrillation (AF) and atrial flutter (AFL), prophylactic cavotricuspid isthmus ablation (CTIA) adjunctive to AF ablation has recently been attempted in patients with AF and without AFL. The present study aimed to determine the rates of AFL occurrence and CTI reconduction after performing CTI ablation adjunctive to AF ablation.Methods: We analyzed the data of 3833 consecutive patients with AF, who underwent prophylactic CTIA with AF ablation between 2009 and 2020.Results: In all patients, CTIA and AF ablations were successful. Clinical AFL occurred in seven patients (0.18%, 7/3,833), and the observed rate was lower than those reported for cases of AF ablation without CTIA and for those of CTIA for pure AFL. A second ablation was needed in 745 patients at a median of 253 days (25 and 75 percentiles, 116 and 775 days) after the first ablation. In 12.1% (90/745) of the patients, CTI reconduction was observed. The reconduction rate was lower than that previously reported for CTIA for pure AFL.Conclusions: The present retrospective study found acceptably low rates of clinical AFL occurrence and CTI reconduction following prophylactic CTIA performed with AF ablation, which was supported by the findings obtained after performing a comparison of the rates with those of other ablations (AF ablation only and CTIA for pure AFL). Considering the high correlation between AF and AFL, the present study provided information regarding the efficacy of adjunctive CTIA. [ABSTRACT FROM AUTHOR]

Background: The efficacy of pulmonary vein isolation (PVI) alone is not guaranteed for persistent atrial fibrillation (PeAF), and it is unclear which type of ablation approach should be applied in addition to PVI. This study aimed to compare outcomes and prognosis between empirical linear ablation and low-voltage area (LVA) ablation after PVI for PeAF.Methods: We enrolled 128 patients with PeAF who were assigned to the linear ablation group (n = 64) and the LVA ablation group (n = 64) using a propensity score-matched model. After PVI and cardioversion, the patients underwent either empirical linear ablation or LVA ablation during sinus rhythm. All patients in the linear ablation group underwent both roof line and mitral valve isthmus (MVI) ablations. An electrical-guided ablation targeting LVA (< 0.5 mV) was performed in the LVA group. When there was no LVA in the LVA group, only PVI was applied. We compared the procedural outcomes and recurrence after ablation between the two groups.Results: The baseline characteristics were well-balanced between the two groups. Fifty patients had LVA (22 and 28 patients in the linear and LVA groups). The roof and MVI lines were completed in 100% and 96.9% of the patients. During the mean follow-up of 279.5 ± 161.3 days, the LVA group had significantly lower recurrence than the linear group (15 patients [23%] vs. 29 patients [45%], p = 0.014). Thirty-five patients were prescribed antiarrhythmic drugs during the follow-up period (linear group, n = 17; LVA group, n = 18); amiodarone and bepridil were administered to most of the patients (15 and 17 patients, respectively). The difference in the prognosis was relevant among the patients with LVA, while this trend was not observed in those without LVA. The LVA ablation group demonstrated significantly lower radiofrequency energy and shorter procedural time compared to the linear ablation group. The recurrence of atrial flutter was more likely to occur in the linear group than in the LVA group (14 [22%] vs. 6 [9.4%], p = 0.052).Conclusion: The electrophysiological-guided LVA ablation is more effective than empirical linear ablation in PeAF patients with LVA. Unnecessary empirical linear ablation might have a risk of iatrogenic gap and atrial flutter recurrence. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the effect of Bachmann bundle (BB) impairment on electrical and mechanical function of the left atrium (LA), as well as the long-term clinical impact of such impairment. We measured activation time in the five LA walls in 56 patients with atrial fibrillation. LA reservoir, conduit, and contractile function were also evaluated. Patients were divided into two groups based on ablation strategy: the circumferential pulmonary vein isolation (CPVI) group and CPVI with LA anterior wall linear ablation (LAAW) group. Patients in the CPVI + LAAW group were divided into two sub-groups based on ECG differences following ablation: the BB impairment group and intact BB group. LA activation time and function were then compared between the ablation strategy groups and the CPVI + LAAW subgroups. Patients in the CPVI + LAAW group exhibited longer activation times in the anterior and lateral walls of the LA, poorer LA synchrony, and reduced LA contractile and reservoir function when compared with those in the CPVI group. In the BB impairment subgroup, we observed a discrepancy between electrical/mechanical remodeling. Among five walls, activation time was longest in this region. BB impairment was also associated with reduced LA function. Significant changes in LA function and conductibility were observed in patients with anterior wall ablation, especially those with iatrogenic BB impairment. [ABSTRACT FROM AUTHOR]

Aims: Previous studies could not demonstrate any benefit of more intensive ablation in addition to pulmonary vein isolation (PVI) including complex fractionated atrial electrogram (CFAE) and linear ablation for recurrence in the initial catheter ablation of persistent atrial fibrillation (AF). This study aimed to establish the non-inferiority of PVI alone to PVI plus these additional ablation strategies.Methods and Results: Patients with persistent AF who underwent an initial catheter ablation (n = 512, long-standing persistent AF; 128 cases) were randomly assigned in a 1:1 ratio to either PVI alone (PVI-alone group) or PVI plus CFAE and/or linear ablation (PVI-plus group). After excluding 15 cases who did not receive procedures, we analysed 249 and 248 patients, respectively. The primary endpoint was recurrence of AF, atrial flutter, and/or atrial tachycardia, and the non-inferior margin was set at a hazard ratio of 1.43. In the PVI-plus group, 85.1% of patients had linear ablation and 15.3% CFAE ablation. After 12 months, freedom from the primary endpoint occurred in 71.3% of patients in the PVI-alone group and in 78.3% in the PVI-plus group [hazard ratio = 1.56 (95% confidence interval: 1.10-2.24), non-inferior P = 0.3062]. The procedure-related complication rates were 2.0% in the PVI-alone group and 3.6% in the PVI-plus group (P = 0.199).Conclusion: This randomized trial did not establish the non-inferiority of PVI alone to PVI plus linear ablation or CFAE ablation in patients with persistent AF, but implied that the PVI plus strategy was promising to improve the clinical efficacy (NCT03514693). [ABSTRACT FROM AUTHOR]

The ablation therapy for persistent atrial fibrillation (PerAF) is still a challenge due to the high recurrence rate. This study was aimed to investigate the value of extensive linear ablation with contact force sensing techniques for PerAF. A total of 214 patients with PerAF were enrolled in five centers. The patients were randomly assigned to Group I (PVI + LA roof line+ LA anterior wall line) and Group II (PVI + LA roof line), mitral valve isthmus lines were added in both groups if the atrial fibrillation (AF) could not be terminated after all approaches above. Acute success rate of AF termination during the ablation procedure in Group I was significantly higher than Group II (P = 0.028). Two-years follow-up showed no significant difference in the sinus rhythm maintenance rate between the two groups (63.4% in group I vs. 57.2% in group II, P = 0.218). More patients in Group I recurred as organized atrial tachycardia (AT) and can be precisely mapped during repeat ablation procedures (15 vs. 2, P = 0.001). The Kaplan–Meier estimates of AF/AT-free survival after repeat ablation procedures were 76.2% in Group I and 47.1% in Group II (P = 0.039). Extensive linear ablation with contact force monitoring did not improve the long-term outcomes for PerAF patients. Repeat ablation procedure showed a possible higher chance of sinus rhythm restoration during follow-up. • Extensive linear ablation increased the rate of AF termination during procedure. • This strategy did not increase success rate at 24 months after single ablation. • This strategy increased sinus rhythm restoration after repeat ablation procedure. [ABSTRACT FROM AUTHOR]

Introduction: When performing linear ablation, creating contiguous and transmural lesions are technically challenging due to the difficulty in finding electrical conduction gaps. We hypothesized that high‐density mapping could identify the gaps. Methods and Results: This study included consecutive patients who underwent conduction gap mapping of de novo lesions (41 patients, 55 lines) and previous lesions (25 patients, 34 lines). We analyzed the utility of bipolar and unipolar conduction gap mapping and retrospectively assessed the voltage and morphology of the bipolar electrograms at the gap sites. Bipolar and unipolar propagation maps were classified into three types: the propagation wavefront traveled through the linear ablation lesions (direct leak), the wavefront jumped to an opposite site across the line and returned to the line (jump and return leak), and others (indefinite leak). In the jump and return leak maps, the site where it returned suggested a conduction gap site. Bipolar propagation maps identified 30 (54.5%) conduction gaps and unipolar maps identified 40 (72.7%) gaps at de novo linear ablation lesions (P =.01), and 32 (94.1%) gaps and 33 (97.1%) gaps, respectively, at previous lesions (P =.56). Bipolar voltage mapping did not add any further efficacy in detecting conduction gaps, and the morphology of the electrograms recorded at the gap sites was not related to the types of propagation maps. Conclusion: Conduction gaps of linear ablation lesions can be visualized by high‐density mapping with a high probability. Unipolar propagation, when used with bipolar mapping, may help detect conduction gap sites. [ABSTRACT FROM AUTHOR]

Background: Atrial linear lesions are generally created with radiofrequency energy. We sought to evaluate the feasibility of cryothermal atrial linear ablation. Methods and Results: Twenty‐one atrial fibrillation (AF) patients underwent linear ablation on the left atrial (LA) roof, mitral isthmus (MI), and cavotricuspid isthmus (CTI) with 8‐mm‐tip cryocatheters following pulmonary vein isolation. The data were compared with those of 31 patients undergoing linear ablation with irrigated‐tip radiofrequency catheters. Conduction block was successfully created in 18 of 20 (90%), 9 of 21 (43%), and 20 of 20 (100%) on the LA roof, MI, and CTI by endocardial cryoablation alone with 19.0 (12.0‐24.0), 30.0 (23.0‐34.0), and 14.0 (14.0‐16.0) minute cryo applications, respectively. The presence of either an interposed circumflex artery or pouch at the MI was significantly associated with failed MI block (P =.04). Conduction block was created in 25 of 31 (83.9%), 27 of 31 (87.1%), and 30 of 31 (96.8%) on the roof, MI, and CTI, respectively, by radiofrequency ablation. During the 17.5 (13.0‐31.7) months of follow‐up, freedom from AF/atrial tachycardia (AT) was significantly higher in the cryo group (P =.05); especially, recurrent AT was more frequent in the RF group (8/31 vs 1/21; P =.03). Conduction block across the roof, MI, and CTI was durable in 6 of 12 (50.0%), 4 of 12 (33.3%), and 9 of 12 (75.0%) patients during second procedures. All nine patients (except one) with recurrent ATs had at least one roof or MI conduction resumption. Conclusions: Cryoablation is effective for creating a roof and CTI linear block, however, creating MI block by endocardial ablation alone was often challenging. Conduction resumption of LA linear block is common and recurrent arrhythmias, especially iatrogenic ATs, are more frequently observed after radiofrequency linear ablation. [ABSTRACT FROM AUTHOR]

Background: The efficacy and safety of adjuvant substrate modification (SM; either linear ablation [LA] or complex fractionated atrial electrogram [CFAE] ablation) in addition to pulmonary vein isolation (PVI) for the treatment of symptomatic, drug-refractory atrial fibrillation (AF), have still not been clarified and need further assessment.Method: We systematically searched the PubMed, MEDLINE, and Cochrane databases for studies comparing PVI with adjunctive SM versus PVI alone for treatment of drug-refractory AF.Results: Twenty-six (26) studies including 3,409 patients (1,975 PVI + SM; 1,434 PVI alone) were included for further analysis. Atrial fibrillation/atrial tachycardia-free survival of patients with PVI + SM was comparable with that of PVI alone (relative risk [RR], 1.06; 95% confidence interval [CI], 0.98-1.14; p = 0.143). In line with this, the primary clinical outcomes were robust, irrespective of additional LA (RR, 1.07; 95% CI, 0.97-1.18; p = 0.194) or CFAE ablation (RR, 1.04; 95% CI, 0.93-1.16; p = 0.534). Adjuvant SM is associated with longer procedural time (weighted mean difference, 20.72; 95% CI, 10.25-31.20; p = 0.0) and fluoroscopy time (weighted mean difference, 6.66; 95% CI, 1.74-11.58; p = 0.000); surprisingly, it presented similar procedure-related complications as PVI alone during AF catheter ablation (RR, 1.01; 95% CI, 0.68-1.50; p = 0.946).Conclusions: Adjuvant LA or CFAE ablation do not provide incremental benefit over PVI alone. Although substrate-based ablation markedly prolonged procedural and fluoroscopic duration, there was no evidence of increased risk of procedure-related complications. [ABSTRACT FROM AUTHOR]

Aims: Achieving block across linear lesions is challenging. We prospectively evaluated radiofrequency (RF) linear ablation at the roof and mitral isthmus (MI) using point-by-point contiguous and optimized RF lesions.Methods and results: Forty-one consecutive patients with symptomatic persistent AF underwent stepwise contact force (CF)-guided catheter ablation during ongoing AF. A single linear set of RF lesions was delivered at the roof and posterior MI according to the 'Atrial LINEar' (ALINE) criteria, i.e. point-by-point RF delivery (up to 35 W) respecting strict criteria of contiguity (inter-lesion distance ≤ 6 mm) and indirect lesion depth assessment (ablation index ≥550). We assessed the incidence of bidirectional block across both lines only after restoration of sinus rhythm. After a median RF time of 7 min [interquartile range (IQR) 5-9], first-pass block across roof lines was observed in 38 of 41 (93%) patients. Final bidirectional roof block was achieved in 40 of 41 (98%) patients. First-pass block was observed in 8 of 35 (23%) MI lines, after a median RF time of 8 min (IQR 7-12). Additional endo- and epicardial (54% of patients) RF applications resulted in final bidirectional MI block in 28 of 35 (80%) patients. During a median follow-up of 396 (IQR 310-442) days, 12 patients underwent repeat procedures, with conduction recovery in 4 of 12 and 5 of 10 previously blocked roof lines and MI lines, respectively. No complications occurred.Conclusion: Anatomical linear ablation using contiguous and optimized RF lesions results in a high rate of first-pass block at the roof but not at the MI. Due to its complex 3D architecture, the MI frequently requires additional endo- and epicardial RF lesions to be blocked. [ABSTRACT FROM AUTHOR]

Background Left ventricular aneurysm (LVA) might be an arrhythmogenic substrate. Endocardiectomy and cryoablation for ventricular tachycardia (VT) with LVA can cause extensive myocardial damage. We aimed to evaluate the feasibility of surgical radial linear ablation for VT with LVA guided by electrophysiological mapping. Materials and methods Porcine models of VT with LVA were developed. Endocardial and epicardial substrate mapping during sinus rhythm were performed under thoracotomy. Surgical radial linear ablation was achieved by a bipolar radiofrequency ablation device. Outcomes, including procedural success and acute freedom of VT, were analyzed. Results Fifteen of 20 pigs developed LVA in a 6-wk survival period. A total of 28 sustained monomorphic VTs were initiated in 13 of 15 pigs (86.67%). The number of potential points captured from the endocardium and epicardium were 319 ± 45 and 358 ± 52 per animal, respectively. The ablative targets containing abnormal potentials were located largely on the border zone of LVA. Eight linear lesions from core to border zone of LVA were achieved per animal in a radial and even manner continuously, and ablation was repeated three times to transect border zone. The acute freedom of VT was 84.62%, P < 0.05. Conclusions Surgical linear endo-epicardial ablation seemed to be feasible in a porcine model with VT and LVA. [ABSTRACT FROM AUTHOR]

Background Clinical utility of irrigation-tip ablation catheters for cavo-tricuspid isthmus (CTI) ablation is established. Recently, new-generation enhanced-cooling irrigation-tip catheters were introduced into clinical use. This study compared the performance of different types of novel irrigation-tip catheters in CTI ablation. Methods One hundred patients undergoing CTI ablation with novel irrigated-tip catheters were included. Ablation was performed with a power output of 30–35 W using either 4-mm flexible tip catheters [FlexAbility (FAs) St. Jude Medical, St. Paul, MN, USA] or 3.5-mm enhanced-cooling ring-tip catheters without [ThermoCool SurroundFlow (SFs), Biosense Webster, Diamond Bar, CA, USA] and with contact force sensing [ThermoCool SmartTouch SurroundFlow (STSFs), Biosense Webster] in 32, 34, and 34 patients, respectively. Results The successful CTI block creation rate was significantly higher for FAs than SFs/STSFs [32/32 (100%), 30/34 (88.2%), and 27/34 (79.4%), p = 0.006]. In all 11 failed procedures, block was created by additional 5 (2–7) applications with 8-mm tip catheters. The radiofrequency (RF) application number ( p = 0.001) and energy ( p = 0.021) were significantly lower, and total RF time ( p = 0.005) and procedure time ( p = 0.036) significantly shorter in the FA than SF/STSF groups. The FA catheter was associated with significantly higher tip temperature readings (34.9 °C vs. 32.0/33.0 °C, p < 0.001) and lower initial impedances than SF/STSF catheters (both p < 0.001). The tip temperature reached the maximum temperature setting in 15/295 (5.1%) FA catheter applications among 11 (34.3%) patients, 0/521 (0%) ST applications, and 0/448 (0%) STSF applications. The mean RF power achieved during RF applications was significantly lower for FA than SF/STSF catheters (28.6 W vs. 30.4/30.8 W, p < 0.001). Audible steam pops were detected in 1/448 applications in only the STSF group. Conclusions In human CTI ablation, flexible irrigation-tip catheters showed a significantly better performance than rigid enhanced-cooling irrigation-tip catheters. [ABSTRACT FROM AUTHOR]

Abstract: Background: In longstanding persistent atrial fibrillation (LPeAF), the ideal endpoint of ablation remains to be determined. This study was to explore the value of pursuing AF termination or no with the same strategy during ablation on the long‐term outcomes in patients with LPeAF. Methods: Utilized “CCL” strategy is a fixed ablation approach consisting of circumferential pulmonary vein antrum isolation, ablation of complex fractionated atrial electrogram, and linear ablation between two anatomical structures (the mitral isthmus, left atrial roof). Note that 400 patients were randomized to group A (technical endpoint) and group B (pursuing AF termination). Results: A group with technical endpoint had lower rate of acute AF termination (AF→sinus rhythm, 3.5% vs 18.1%; AF→atrial tachycardia, 23.7% vs 44.7%; P < 0.01) and shorter duration of ablation (164.9 ± 20.8 vs 223.4 ± 24.9, P < 0.01), radiofrequency delivery time (69.8 ± 18.1 vs 102.2 ± 26.3, P < 0.01), and x‐ray exposure time (18.2 ± 8.8 vs 27.9 ± 12.4, P < 0.01) than those in B group (pursuing AF termination). During follow‐up, freedom from atrial arrhythmias did not differ between the two groups after a single ablation procedure (46.5% vs 54.3%, P=0.12) and the final ablation procedure (60.1% vs 65.8%, P  =  0.24). Conclusion: In patients of LPeAF, pursuing AF termination during ablation was associated with similar long‐term clinical outcome compared to that with technical endpoint. Ablation to termination is not the best strategy during ablation. [ABSTRACT FROM AUTHOR]

BackgroundAlthough circumferential pulmonary vein isolation (CPVI) catheter ablation may not be sufficient for long‐standing persistent atrial fibrillation (L‐PeAF), it is not clear which ablation strategy is beneficial in addition to CPVI. We sought to investigate whether additional complex fractionated atrial electrogram (CFAE)‐guided ablation improves clinical outcomes in L‐PeAF patients who exhibit continuous atrial fibrillation (AF) after CPVI and linear ablation (Line). Methods and ResultsThis study enrolled 137 L‐PeAF patients (71.4% male, 61.6±10.9 years old) who underwent radiofrequency catheter ablation. We conducted CPVI+Line based on the Dallas lesion set (posterior box+anterior line) after baseline CFAE mapping in all patients. If AF was defragmented (terminated or changed to atrial tachycardia), the procedure was stopped (AF‐Defrag group, n=29). If AF was maintained after CPVI+Line, we mapped the CFAE again and randomly assigned the patient to the CPVI+Line group (n=54) or the additional CFAE ablation group (CPVI+Line+CFAE group, n=54). L‐PeAF was defragmented during CPVI+Line in 21.2% of patients (29/137, AF‐Defrag group). The mean CFAE cycle length was prolonged (P

Background Data on the roof line (RL) and mitral isthmus line (MIL) reconnections after atrial fibrillation (AF) catheter ablation (CA) are scarce. Objective We studied the RL and MIL completeness and localization of reconnection sites in consecutive patients after their first-ever AF-CA. Methods We prospectively included 41 consecutive AF patients who underwent predefined lesion sets of two circumferential lines (CLs) for ipsilateral pulmonary vein isolation (PVI) combined with a RL and lateral MIL. Three months after CA, all patients underwent invasive follow-up procedure for line persistency evaluation, irrespective of clinical outcome. Results At the time of index ablation, PVI-CLs, RL, and MIL was completed in 41 (100%), 39 (95%), and 34 (83%) of patients, respectively. At the 3-month follow-up procedure, reconnections of PVI-CLs, RL, and MIL were found in 61% (25/41), 28% (11/39), and 24% (8/34) of patients, respectively. The 3-month reconnections were located commonly in the anterior and posterior PVI-CL segments, and rarely in the right third of RL and in the posterior part of MIL. The 3-month reconnections were rarely seen at the sites of acute reconnections during index procedure (6%, 20%, and 25% of the PVI-CL segments, RL segments, and MIL segments, respectively). Conclusions To our knowledge, this is the first study systematically investigating the reconnection of standardized left atrium linear lesions such as RL and MIL after RF-CA for AF in consecutive patients. The RL and MIL 3-month reconnection rates were relatively low (28% and 24%), with poor anatomical concordance between the sites with acute and 3-month reconnections. [ABSTRACT FROM AUTHOR]

The mitral isthmus is a part of the postero-inferior area of the lateral left atrial wall located between the mitral annulus and the left inferior pulmonary vein ostium. Linear ablation lesions are created within the mitral isthmus for the invasive treatment of left atrial arrhythmias. However, the anatomy of this region is not fully understood. The aim of this study has been to provide a detailed morphometric description of the mitral isthmus region and to propose another possible isthmus within the investigated heart area that may serve as a potential new ablation target. Two hundred autopsied, non-atrial fibrillation hearts (23.5% deriving from females) whose donors were a mean of 47.6 ± 17.6 years old were investigated. We macroscopically assessed the anatomy of the postero-inferior area of the lateral left atrial wall. The mean mitral isthmus length was 28.8 ± 7.0 mm and was significantly longer than the left atrial appendage (LAA) isthmus (14.2 ± 4.8 mm) (p = .00). The distance between the LAA orifice and the left inferior pulmonary vein ostium (18.4 ± 4.8 mm) was longer than the LAA isthmus (p = .00) and shorter than the mitral isthmus (p = .00). The LAA isthmus was longer in hearts with a common left pulmonary vein (p = .037). In 65.5% of all cases the area between the right and left mitral isthmus lines was completely smooth. In the remaining hearts, crevices and diverticula (18.0%), intertrabecular recesses (7.0%), trabecular bridges (3.5%), or co-existence of these structures (6%) could be observed. The LAA isthmus line was smooth in 95.5% of all cases, with only small crevices in the remaining 4.5%. In conclusion, regardless of the anatomical variants of the left-sided pulmonary veins, the mitral isthmus area is quite uniform in size. The LAA isthmus is considerably shorter than the mitral isthmus. The mitral isthmus line has many unwanted structures that may entrap the catheter, which is not the case for the LAA isthmus. We proposed the LAA isthmus line for potential clinical use. [ABSTRACT FROM AUTHOR]

BackgroundIt is not clear whether bidirectional block (BDB) of linear ablations reduces atrial fibrillation (AF) recurrence after radiofrequency catheter ablation. We hypothesized that BDB of linear ablation has prognostic significance after radiofrequency catheter ablation for persistent AF. Methods and ResultsAmong 1793 consecutive patients in the Yonsei AF ablation cohort, this observational cohort study included 398 patients with persistent AF (75.6% male; age, 59.8±10.3 years) who underwent catheter ablation with a consistent ablation protocol of the Dallas lesion set: circumferential pulmonary vein isolation; cavotricuspid isthmus ablation (CTI); roof line (RL); posterior‐inferior line (PIL); and anterior line (AL). BDB rates of de novo ablation lines were 100% in circumferential pulmonary vein isolation, 100% in CTI, 84.7% in RL, 44.7% in PIL, and 63.6% in AL. During 29.0±18.4 months of follow‐up, 31.7% (126/398) of the patients showed clinical recurrence. Left atrial posterior wall (LAPW) isolation (BDBs of RL and PIL) was independently associated with lower clinical AF/atrial tachycardia recurrence (hazard ratio, 0.68; 95% CI, 0.47–0.98; P=0.041; log‐rank, P=0.017), whereas BDBs of RL or AL were not (log‐rank, P=0.178 for RL; P=0.764 for AL). Among 52 patients who underwent repeat procedures (23.0±16.1 months after de novo procedure), the BDB maintenance rates for CTI, RL, PIL, and AL were 94.2% (49 of 52), 63.5% (33 of 47), 62.1% (18 of 29), and 61.8% (21 of 34), respectively. ConclusionsAlthough PIL crosses the esophageal contact area, LAPW isolation is important for better clinical outcome in catheter ablation with a linear ablation strategy for patients with persistent AF.

Non-pharmacological rhythm control of atrial fibrillation (AF) is becoming increasingly important in our aging society. Advancement of catheter ablation techniques in the last decade has provided a cure for AF patients, with a nearly established efficiency for paroxysmal cases. However, since ablation of persistent/chronic AF cases is still challenging, early treatment of paroxysmal AF before transformation to the persistent/chronic form is mandatory. Although there is a consensus that pulmonary vein isolation is the first-line approach for ablation of long-standing persistent AF, similar to that for paroxysmal AF, there are still wide variations in the adjunctive approach to modify the atrial substrate of persistent AF (anatomical linear ablation, electrogram-based complex fractionated atrial electrogram ablation, ganglionated plexus ablation, etc.). Since data comparing the effectiveness of these adjunctive approaches are still lacking, large-scale controlled trials evaluating the effect of catheter ablation in diverse patient populations on a long-term basis are needed to establish the appropriate approach for long-standing persistent AF. Furthermore, the development of de novo ablation methods (new energies, new targets, etc.) is expected to improve ablation outcome in patients with long-standing persistent AF.

Introduction: We describe the use of a ablating system to compartmentalise and regionally isolate the atria in paroxysmal and persistent atrial fibrillation (AF). Methods: 40 patients were studied, 25 paroxysmal AF and 14 persistent AF. One patient enrolled was later found to be in left atrial flutter and was excluded. The Cardima Revelation® TX catheter system with Intellitemp® Radiofrequency (RF) energy control device and a Medtronic Atakar® RF generator were used to place wide area circumferential ablations to achieve conduction block into the left and right sided pulmonary veins. Roof lines and mitral isthmus lines were also performed. In patients with persistent AF and in repeat procedures, right atrial compartmentalisation was performed with an anterior superior vena cava (SVC) to inferior vena cava (IVC) line and a septal SVC to IVC line. Results: At 6 months, 18 of the 39 patients were asymptomatic, 10 had improved symptoms and 22 were in sinus rhythm. In the paroxysmal group, 11 were asymptomatic, 7 had improved symptoms and 16 (64%) were in sinus rhythm. In the persistent group, 7 were asymptomatic, 3 had improved symptoms and 6 (43%) were in sinus rhythm. The total group AF burden was 37.8±5.4 hrs pre-procedure and 23.1±5.1 hrs at 6 months post procedure. Mean temperature, impedance and power recorded at each pole demonstrated effective power delivery at all poles. No catheter charring was observed, complication rates were comparable to standard AF ablation technique. Conclusion: Linear ablation in the left and right atria to mimic Cox’s Maze is feasible and safe using this ablating system.

Background The benefits and risks of additional left atrium (LA) linear ablation in patients with paroxysmal atrial fibrillation (AF) remain unclear. Methods Randomized controlled trials were identified in the PubMed, Web of Science, Embase and Cochrane databases, and the relevant papers were examined. Pooled relative risks (RR) and 95% confidence interval (95% CI) were estimated using random effects models. The primary endpoint was the maintenance of sinus rhythm after a single ablation. Results Nine randomized controlled trials involving 1138 patients were included in this analysis. Additional LA linear ablation did not improve the maintenance of the sinus rhythm following a single procedure (RR, 1.03; 95% CI, 0.93–1.13; P = 0.60). A subgroup analysis demonstrated that all methods of additional linear ablation failed to improve the outcome. Additional linear ablation significantly increased the mean procedural time (166.53 ± 67.7 vs. 139.57 ± 62.44 min, P < 0.001), the mean fluoroscopy time (54.56 ± 38.7 vs. 44.32 ± 31.6 min, P < 0.001) and the mean radiofrequency (RF) energy application time (78.94 ± 28.39 vs. 59.74 ± 22.38 min, P < 0.001). No statistically significant differences in the rates of complications were noted (RR, 0.57; 95% CI, 0.27–1.19; P = 0.13). Conclusions Additional LA linear ablation did not exhibit any benefits in terms of sinus rhythm maintenance for paroxysmal AF patients following a single procedure. Additional linear ablation significantly increased the mean procedural, fluoroscopy and RF application times. This additional ablation was not associated with a statistically significant increase in complication rates. This finding must be confirmed by further large, high-quality clinical trials. [ABSTRACT FROM AUTHOR]

Aims: This prospective clinical trial was designed to evaluate the efficacy of an ablation strategy, namely '2C3L', in the treatment of persistent atrial fibrillation (AF); and to compare its efficacy with that of the 'stepwise' approach, which has been acknowledged as a promising ablation technique for persistent AF.Methods and Results: The '2C3L' technique is a fixed ablation approach consisting of bilateral circumferential pulmonary vein antrum isolation (PVAI) and three linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavo-tricuspid isthmus. One hundred and forty-six patients with persistent AF were randomized to undergo ablation by using the '2C3L' or the 'stepwise' technique (n = 73, respectively). The primary endpoint was freedom from any atrial tachyarrhythmia off antiarrhythmic drug (AAD) after a single procedure at follow-up. Twelve months after a single procedure, there was no difference in sinus rhythm (SR) maintenance rate between the two groups (67% for '2C3L' vs. 60% for 'stepwise', P = 0.394; 95% confidence interval of between-group difference -8.7 to 22.4%). The procedure (222 ± 42 vs. 263 ± 41 min), fluoroscopy (41 ± 9 vs. 55 ± 8 min), and radiofrequency (RF) (107 ± 32 vs. 128 ± 38 min) time were significantly shorter in the '2C3L' group (all P < 0.001). At 25 ± 5 months after the first procedure, 57.5 and 52.1% of patients from the '2C3L' group and the 'stepwise' group were in SR off AAD (P = 0.494), respectively.Conclusions: For catheter ablation of persistent AF, the '2C3L' strategy is a fixed approach associated with clinical efficacy similar to that of the 'stepwise' approach but with less RF delivery, fewer X-ray exposure, and shorter procedural time. [ABSTRACT FROM AUTHOR]

Consequences of Left Atrial Anterior Wall Linear Ablation Objective As an alternative to the mitral isthmus line (MIL), the left atrial anterior wall line (LAAWL) is effective for the treatment of perimitral flutter. This study evaluated the electrophysiologic and clinical outcomes of LAAWL versus MIL in patients with persistent atrial fibrillation (AF). Methods Two hundred patients with persistent AF were evenly randomized to the LAAWL and MIL groups. After confirming bidirectional block of the line, left atrial appendage (LAA) activation time and LA propagation pattern were assessed during sinus rhythm (SR). Transthoracic and transesophageal echocardiography (TTE and TEE) were performed at 12 months after ablation in patients who remained in stable SR. Results In the 74 patients with LAAWL conduction block relative to the 79 with MIL conduction block, LA propagation contour was markedly changed with delayed LAA potential (longer P-wave onset-to-LAA potential interval: 151.7 ± 19.5 vs. 67.8 ± 18.3 milliseconds, P < 0.001); TTE peak A velocity was lower and LAA emptying wave was delayed in the LAAWL group compared with the MIL group; spontaneous echo contrast (SEC) detected in the LAAWL group was significantly higher than that in the MIL group (15.8% vs. 1.6%, p = 0.0004). During a mean follow-up period of 31.8 ± 9.4 (22-57) months, there were 5 cases of stroke in the LAAWL group, which was significantly different from the MIL group (5% vs. 0%, P = 0.047). Conclusions Complete linear lesions transecting the anterior LA were associated with a significant change in the SR propagation pattern with late activation of LAA. This might result in an increased risk of long-term thrombo-embolism events. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines). [ABSTRACT FROM AUTHOR]

Background Recurrent perimitral atrial tachycardia (AT) is a challenging arrhythmia and is frequently encountered in the context of atrial fibrillation (AF) ablation. Objective The purpose of this study was to investigate the clinical characteristics and the procedural and clinical outcomes in patients with recurrent perimitral atrial tachycardia (PMAT) after AF ablation. Methods Among 520 consecutive ablation procedures for recurrent AT/AF after AF ablation, 40 procedures (patients) were performed for clinically recurrent PMAT 12.1 ± 13.6 months after the last procedure (total 2.2 ± 1.3 procedures). Previously, mitral isthmus (MI) linear ablation was performed in 26 of 40 procedures, including 13 procedures with complete block and 13 with 159.0 ± 23.0 ms of conduction delay without block. As a reference group, conduction delay was evaluated in 55 patients with incomplete MI block and absence of spontaneous PMAT during the follow-up period. Results Recurrent PMATs were terminated by MI linear ablation in 26 of 40 patients. Bidirectional block across the MI and anterior line joining the mitral annulus and left atrial roof was achieved in 33 (82.5%) and 2 (5%) patients, respectively. At mean follow-up of 26.7 ± 14.5 months, 2 patients (5%) underwent reablation for spontaneously recurrent PMAT. At 12 months after the ablation procedure for PMAT, 73.5% of the patients were free from AT/AF. Conduction delay >149 ms predicted the occurrence of spontaneous PMAT with 80.0% sensitivity and 87.3% specificity. Conclusion PMAT can recur even after successful bidirectional MI linear block. Substantial conduction delay without block across the MI from a previous procedure(s) could predispose to recurrent PMAT. Although most clinical PMATs can be successfully treated by catheter ablation, very late recurrence is possible. [ABSTRACT FROM AUTHOR]

Abstract: Background: Although a large isolated surface area of the left atrium (LA) may improve the success rate of catheter ablation (CA) for paroxysmal atrial fibrillation (AF), little is known about the relation between clinical outcomes and the amount of atrial mass reduction (AMR: ratio of total isolated and ablated areas to LA surface area) in different ablation strategies for patients with long-standing persistent AF (L-PeAF). Methods: We randomly assigned 119 consecutive L-PeAF patients to adjunctive linear ablation (n =60) or complex fractionated atrial electrogram (CFAE)-guided ablation (n =59) after circumferential antral pulmonary vein isolation (PVI). Linear lesions included roof and anterior lines with conduction block. LA defragmentation was performed with an automated CFAE-detection algorithm. Cavotricuspid isthmus block was performed in all patients. Creatine kinase-MB (CK-MB) and troponin-T levels were measured 1day post-CA. Results: CK-MB and troponin-T levels were higher, ablation time was longer, and AMR was greater in the CFAE-guided ablation group than in the linear ablation group. AF termination during CA was more frequently observed in the linear ablation group than in the CFAE-guided ablation group (P =0.031). Twelve months after a single procedure, recurrence occurred in 16 (26.7%) patients with linear ablation and 27 (45.8%) patients with CFAE-guided ablation (P =0.023). On multivariate analysis, LA volume and ablation method were the only independent risk factors for arrhythmia recurrence. Conclusion: Conduction block through linear lines+PVI was an efficient ablation strategy for L-PeAF, whereas the AMR amount did not influence clinical outcomes. [Copyright &y& Elsevier]

Background: While macroreentrant atrial tachycardias (ATs) have been reasonably well described, little is known about small reentrant circuits. Objective: To compare characteristics of large and small reentrant circuits after ablation of persistent atrial fibrillation. Methods: Seventy-seven patients (age 61±10 years; left atrium 46±6 mm; ejection fraction 0.52±0.13) underwent a procedure for postablation AT. The p-wave duration, circuit size, electrogram characteristics, and conduction velocity were determined. Results: AT was due to macroreentry in 62 (80%) patients, a small reentrant circuit in 13 (17%), and a focal mechanism in 2 (3%). The p-wave duration during small reentrant ATs was shorter than that during macroreentry (174±12 ms vs 226±22 ms; P<.0001). The duration of fractionated electrograms at the critical site was longer in small vs large circuits (167±43 ms vs 98±38 ms, respectively; P<.0001) and accounted for a greater percentage of the tachycardia cycle length (59%±18% vs 38%±14%, respectively; P<.0001). The mean diameters of macroreentrant and small reentrant circuits were 44±7 and 26±11 mm, respectively (P<.0001). The mean conduction velocity along the small circuits was lower (0.5±0.2 m/s vs 1.2±0.3 m/s; P<.0001). Catheter ablation eliminated the AT in all 77 patients. Conclusions: AT due to a small reentrant circuit after ablation of atrial fibrillation may be distinguished from macroreentry by a shorter p-wave duration and the presence of long-duration electrograms at the critical site owing to extremely slow conduction. These features may aid the clinician in the mapping of postablation ATs. [ABSTRACT FROM AUTHOR]