Search

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society., Competing Interests: Data availability No new data were generated or analyzed in support of this research., (Copyright © 2024. Published by Elsevier Inc.)

Background: Young atrial fibrillation (AF) patients have been underrepresented in studies of radiofrequency catheter ablation (RFCA) and the outcome of RFCA has not been widely addressed. We investigated age-related differences in clinical features, the recurrence of atrial tachyarrhythmia, and its predictors of patients who underwent RFCA for AF., Methods: This is a multicenter prospective study of 2799 patients who underwent RFCA for AF in 2017-2020. The patients were divided into two groups - group A (age < 60 years, n = 1269) and group B (age ≥ 60 years, n = 1530) - and a recurrence of any atrial tachyarrhythmia 1 year after RFCA following a 90-day blanking period was compared., Results: The mean age was 51.6 ± 6.7 and 66.8 ± 5.2 years for groups A and B, respectively. Higher body mass index, smaller left atrium, and more prevalent cardiomyopathy and obstructive sleep apnea were observed in group A. Overall, 1-year atrial tachyarrhythmia-free survival was 85.6% and lower in young patients (83.1% in group A vs. 87.7% in group B, log-rank p < 0.01): adjusted hazard ratio (aHR) of recurrence (95% confidence interval (CI)), 1.45 (1.13-1.86) for group A compared to group B (p < 0.01). The association between younger age and higher recurrence was continuously observed in patients under 60 years. Any non-PV ablation was associated with a lower recurrence of atrial tachyarrhythmia in group B (aHR 0.68 (0.47-0.96), p < 0.05), but not in group A., Conclusions: AF patients younger than 60 years had a higher 1-year AF recurrence after RFCA. Young AF patients might have distinctive pathophysiology of AF requiring more integrated management., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Impaired atrial functional reserve during exercise may represent an early stage of atrial cardiomyopathy. To test this hypothesis, the authors evaluated left atrial (LA) and left ventricular (LV) function reserve during exercise in patients with paroxysmal atrial fibrillation (PAF)., Methods: Sixty-one patients with PAF undergoing radiofrequency catheter ablation and 38 healthy control subjects were prospectively enrolled. LV global longitudinal strain and LA reservoir strain (RS) were measured at rest and during supine bicycle exercise. To identify the early stage of atrial cardiomyopathy without LA structural remodeling, patients with PAF were divided into two groups according to LA volume index (LAVI): atrial fibrillation (AF) group 1 (LAVI ≥ 34 mL/m 2 ) and AF group 2 (LAVI < 34 mL/m 2 )., Results: LV ejection fraction and global longitudinal strain did not differ between patients with AF and control subjects. LAVI and LA RS did not differ between AF group 2 and control subjects. During exercise, LV global longitudinal strain improved in all groups. Increases in LA RS were attenuated in both AF groups, which also exhibited lower LA functional reserve index than the control subjects. Although resting LA RS was similar between AF group 2 and control subjects, LA functional reserve index was significantly lower in AF group 2. LA functional reserve index was associated with risk for AF recurrence (hazard ratio, 0.852; 95% CI, 0.736-0.988)., Conclusions: Atrial cardiomyopathy can be anticipated by impaired LA functional reserve during exercise in patients with AF, even in those with normal-sized left atria. Atrial cardiomyopathy occurs independently of changes in LV function and is associated with the recurrence of AF in patients with PAF after radiofrequency catheter ablation., (Copyright © 2022 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

Aims: An epicardial approach is an effective means to detect and eliminate residual potentials in non-transmural lesions created during prior endocardial ablation. We sought to determine the impact of a combined epicardial and endocardial approach compared with a conventional endocardial approach, on recurrence-free survival after redo ablation., Methods and Results: Participants with recurred persistent atrial fibrillation after prior endocardial ablation were randomized (1:1) to undergo treatment with the combined approach (epicardial followed by endocardial ablation) for the treatment group or conventional approach (endocardial ablation only) for the control group. The primary outcome was the time to recurrence of atrial fibrillation or atrial tachycardia following a 90-day blanking period within 12 months after the procedure. The secondary safety outcome was the occurrence of procedure-related complications within 24 h after the procedure. Of 100 randomized participants {median age, 59.0 [(interquartile range (IQR): 53.8-64.3] years, including 16% women, with one prior ablation (IQR: 1-1)}, 93 (93%) completed the trial. Events relevant to the primary outcome occurred in 16 patients in the treatment group and in 21 patients in the control group {Kaplan-Meier estimator percentages, 32 vs. 42%; hazard ratio, 0.71 [95% confidence interval (CI): 0.37-1.37]}. The periprocedural complication rate was lower in the treatment group [2 vs. 16%; odds ratio, 0.11 (95% CI: 0.00-0.87)] with similar achievement of the procedural endpoint in the two groups., Conclusion: In the redo procedure for persistent atrial fibrillation, the combined approach had no significant difference of recurrence-free survival and a lower procedural complication rate compared with the conventional approach., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Catheter ablation as first-line therapy for ventricular tachycardia (VT) at the time of implantable cardioverter defibrillator (ICD) implantation has not been adopted into clinical guidelines. Also, there is an unmet clinical need to prospectively examine the role of VT ablation in patients with nonischemic cardiomyopathy, an increasingly prevalent population that is referred for advanced therapies globally., Methods: We conducted an international, multicenter, randomized controlled trial enrolling 180 patients with cardiomyopathy and monomorphic VT with an indication for ICD implantation to assess the role of early, first-line ablation therapy. A total of 121 patients were randomly assigned (1:1) to ablation plus an ICD versus conventional medical therapy plus an ICD. Patients who refused ICD (n=47) were followed in a prospective registry after stand-alone ablation treatment. The primary outcome was a composite end point of VT recurrence, cardiovascular hospitalization, or death., Results: Randomly assigned patients had a mean age of 55 years (interquartile range, 46-64) and left ventricular ejection fraction of 40% (interquartile range, 30%-49%); 81% were male. The underlying heart disease was ischemic cardiomyopathy in 35%, nonischemic cardiomyopathy in 30%, and arrhythmogenic cardiomyopathy in 35%. Ablation was performed a median of 2 days before ICD implantation (interquartile range, 5 days before to 14 days after). At 31 months, the primary outcome occurred in 49.3% of the ablation group and 65.5% in the control group (hazard ratio, 0.58 [95% CI, 0.35-0.96]; P =0.04). The observed difference was driven by a reduction in VT recurrence in the ablation arm (hazard ratio, 0.51 [95%CI, 0.29-0.90]; P =0.02). A statistically significant reduction in both ICD shocks (10.0% versus 24.6%; P =0.03) and antitachycardia pacing (16.2% versus 32.8%; P =0.04) was observed in patients who underwent ablation compared with control. No differences in cardiovascular hospitalization (32.0% versus. 33.7%; hazard ratio, 0.82 [95% CI, 0.43-1.56]; P =0.55) or mortality (8.9% versus 8.8%; hazard ratio, 1.40 [95% CI, 0.38-5.22]; P =0.62]) were observed. Ablation-related complications occurred in 8.3% of patients., Conclusions: Among patients with cardiomyopathy of varied causes, early catheter ablation performed at the time of ICD implantation significantly reduced the composite primary outcome of VT recurrence, cardiovascular hospitalization, or death. These findings were driven by a reduction in ICD therapies., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT02848781.

Larger left atrial appendage (LAA) volume is associated with a higher risk of late recurrence (LR) in patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). However, it is unclear whether LAA volume predicts LR, independent of established risk factors. We sought to evaluate the value of LAA volume in predicting LR after RFCA for AF and to develop a score prediction model including LAA volume for these patients. We retrospectively studied 992 patients who underwent RFCA for AF and cardiac computed tomography before RFCA at a single center. At 3 years after RFCA, 362 patients (36.5 %) experienced recurrence. The multivariate Cox regression model showed that age ≥ 75 years (10 points), non-paroxysmal AF (9 points), diabetes mellitus (4 points), left atrial volume index (1 point per 10 ml/m 2 rounded to the nearest integer), and the second (4.7 to < 7 ml/m 2 ; 4 points) and third (≥ 7 ml/m 2 ; 5 points) tertiles of the LAA volume index were independent risk factors LR. The above-mentioned risk factors were included in the integrated score model, and the C-index of the proposed score model was 0.715 (95 % confidence interval [CI] 0.679-0.752). LAA volume is an independent predictor of LR and the predictive model including LAA volume showed good discrimination power. These findings provide evidence for the inclusion of LAA volume in the risk stratification for AF recurrence in patients undergoing RFCA for AF.

Objective: To assess the effect of left atrial appendage (LAA) isolation on LAA emptying and left atrial (LA) function using cardiac MRI in patients who underwent successful catheter ablation of atrial fibrillation (AF)., Materials and Methods: This retrospective study included 84 patients (mean age, 59 ± 10 years; 67 males) who underwent cardiac MRI after successful catheter ablation of AF. According to the electrical activity of LAA after catheter ablation, patients showed either LAA isolation or LAA normal activity. The LAA emptying phase (LAA-EP, in the systolic phase [SP] or diastolic phase), LAA emptying flux (LAA-EF, mL/s), and LA ejection fraction (LAEF, %) were evaluated by cardiac MRI., Results: Of the 84 patients, 61 (73%) and 23 (27%) patients showed LAA normal activity and LAA isolation, respectively. Incidence of LAA emptying in SP was significantly higher in LAA isolation (91% vs. 0%, p < 0.001) than in LAA normal activation. LAA-EF was significantly lower in LAA isolation (40.1 ± 16.2 mL/s vs. 80.2 ± 25.1 mL/s, p < 0.001) than in LAA normal activity. Furthermore, LAEF was significantly lower in LAA isolation (23.7% ± 11.2% vs. 31.1% ± 16.6%, p = 0.04) than in LAA normal activity. Multivariate analysis demonstrated that the LAA-EP was independent from LAEF ( p = 0.01)., Conclusion: LAA emptying in SP may be a critical characteristic of LAA isolation, and it may adversely affect the LAEF after catheter ablation of AF., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2021 The Korean Society of Radiology.)

Introduction: Hemodynamics of left atrial appendage (LAA) is an important factor for future risk of ischemic stroke in atrial fibrillation (AF) patients. Velocity encoded cardiac magnetic resonance imaging (VENC-MRI) can evaluate blood flow volume of LAA without any invasive procedures. We aimed to evaluate the association between radiofrequency catheter ablation (RFCA) and LAA hemodynamics measured by MRI., Methods and Results: Consecutive RFCA cases in a single arrhythmia center were retrospectively analyzed. A total of 3120 AF patients who underwent first RFCA were analyzed. Among these patients 360 patients had both pre- and post-RFCA VENC-MRI evaluation. Atrial fibrillation was non-paroxysmal in 174 (48.3%) patients. Mean VENC-MRI (ml/sec) was significantly improved after RFCA with 49.93 ± 32.92 and 72.00 ± 34.82 for pre- and post-RFCA, respectively. Patients with non-paroxysmal AF (∆VENC-MRI = 14.63 ± 40.67 vs. 30.03 ± 35.37; p < .001) and low pre-RFCA VENC-MRI (∆VENC-MRI = 17.19 ± 38.35 vs. 50.35 ± 29.12; p < .001) had significantly higher improvement in VENC-MRI. Those who experienced late recurrence before post-RFCA MRI had significantly less improvement in LAA flow volume (∆VENC-MRI = 15.55 ± 41.41 vs. 26.18 ± 36.77; p = .011). Late recurrence and pre-RFCA VENC-MRI were significantly associated with ∆VENC-MRI after adjusting covariates. Patients who were AF before RFCA but maintained sinus rhythm after RFCA showed greatest improvement in VENC-MRI., Conclusion: Effective rhythm control through RFCA can be associated with significant improvement in LAA hemodynamics. Low pre-RFCA VENC-MRI and absence of late recurrence were associated with greater improvement in LAA hemodynamics., (© 2021 Wiley Periodicals LLC.)

Objectives: This study aimed to compare the risk of late recurrence in patients with and without early recurrence., Background: Early recurrence of atrial fibrillation (AF) or atrial tachycardia (AT) after radiofrequency catheter ablation (RFCA) in AF patients is known to be a transient phenomenon. The theoretical basis of the blanking period is based on such observations. However, the clinical implications of early recurrence need further validation., Methods: Consecutive RFCA cases in a tertiary hospital were analyzed. Early recurrence was defined as any AT or AF event occurring within 90-days post-RFCA. Early recurrence as AT and AF were also analyzed separately., Results: A total of 3,120 patients underwent RFCA. Early recurrence occurred in 751 patients (24.1%). Patients who experienced early recurrence had a larger left atrium, worse hemodynamics in the left atrial appendage, and a higher prevalence of nonparoxysmal AF and heart failure. Among patients who experienced early recurrence, 69.6% of patients eventually had late recurrence. Early recurrence was associated with a 4.3- and 3.6-fold increase in the risk of late recurrence after single and multiple procedures, respectively. After multivariate adjustment, early recurrence was an independent risk factor for late recurrence with 3.6- and 2.8-fold increase in the risk of late recurrence after single and multiple procedures, respectively. Early recurrence AT had a lower risk of late recurrence compared with early recurrence AF., Conclusions: Early recurrence was a reliable predictor for late recurrence. The clinical significance of the blanking period in the current guidelines may need to be revisited., Competing Interests: FUNDING SUPPORT AND AUTHOR DISCLOSURES This work was supported by a Korea University Grant (to Dr. J.I. Choi), a grant from Korea University Anam Hospital, Seoul, Republic of Korea (grant No. K1922851), and in part, by grants from the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education (NRF-2015R1D1A1A02061859 to Dr. J.I. Choi), and the Ministry of Science, ICT, and Future Planning (NRF-2012R1A1A1013260 to Dr. J. I. Choi). The funders had no role in data collection, analysis, or interpretation; trial design; patient recruitment; or any aspect pertinent to the study. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: This study evaluated the status of single nucleotide polymorphisms (SNPs) in Korean patients with early-onset (< 40 years old) atrial fibrillation (AF) and their effects on the outcome after catheter ablation., Methods: A total of 89 patients (35.7 ± 3.7 years, 81 males) with drug-refractory AF (paroxysmal 64.0%) who underwent catheter ablation were included in this study. Sixteen SNPs, including rs13376333, rs10465885, rs10033464, rs2200733, rs17042171, rs6843082, rs7193343, rs2106261, rs17570669, rs853445, rs11708996, rs6800541, rs251253, rs3807989, rs11047543, and rs3825214, were genotyped. Serial 48-hour Holter monitoring was conducted to detect AF recurrences during long-term follow up., Results: Wild-type genotypes of rs11047543 (GG; 26/69 [37.7%] vs. GA; 13/18 [72.2%] vs. AA; 0/0 [0%], P = 0.009) and rs7193343 (CC; 0/7 [0%] vs. CT; 22/40 [55.0%] vs. TT; 18/41 [43.9%], P = 0.025) and the homozygous variant of rs3825214 (AA; 16/31 [51.6%] vs. AG; 22/43 [51.2%] vs. GG; 2/13 [15.4%], P = 0.056) were significantly associated with a lower rate of late recurrence. When the patients were assigned to four groups according to the number of risk alleles (n = 0-3), there were significant differences in recurrence rate (n = 0; 0/3 vs. n = 1; 2/13 [15.4%] vs. n = 2; 24/52 [46.2%] vs. n = 3; 13/17 [76.5%], P = 0.003). When correcting for multiple variables, rs11047543 (hazard ratio [HR], 2.723; 95% confidence interval [CI], 1.358-5.461; P = 0.005) and the number of risk alleles (HR, 2.901; 95% CI, 1.612-5.219; P < 0.001) were significantly associated with recurrence of AF after catheter ablation., Conclusion: Polymorphisms on rs7193343 closest to ZFHX3 (16q22), rs3825214 near to TBX5 (12q24), and rs11047543 near to SOX5 (12p12) modulate the risk for AF recurrence after catheter ablation. The number of risk alleles of these 3 SNPs was an independent predictor of recurrence during long-term follow up in Korean patients with early-onset AF., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Open irrigation ablation catheters are now the standard in radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Among various irrigation catheters, laser-cut slit-based irrigation system (Cool Flex and FlexAbility) has a unique design to cool the catheter tip more efficiently. We aimed to assess the safety of slit-based irrigation catheters regarding prevention of procedure-related ischemic complication in AF patients undergoing RFCA. The analysis was performed with Korea University Medicine Anam Hospital RFCA registry. Procedure-related ischemic complication was defined as ischemic stroke or transient ischemic attack (TIA) occurring within 30 days after RFCA. Patients were divided into 3 groups: non-irrigation, hole-based irrigation, and slit-based irrigation catheter groups. A total of 3,120 AF patients underwent first RFCA. Non-irrigation, non-slit-based irrigation, and slit-based irrigation catheters were used in 290, 1,539, and 1,291 patients, respectively. As compared with non-irrigation and non-slit-based irrigation catheter groups, slit-based irrigation catheter group had significantly older age, higher prevalence of non-paroxysmal AF, large left atrial size, and decreased left atrial appendage flow velocity. The CHA2DS2-VASc score was not different among the 3 groups. Procedure-related ischemic complication occurred in 17 patients (0.54%) with 16 ischemic strokes and 1 TIA event: 5/290 (1.72%), 11/1,539 (0.71%), and 1/1,291 (0.08%) events in non-irrigation, non-slit-based irrigation, and slit-based irrigation catheter groups, respectively (p = 0.001). Slit-based irrigation catheter was superior in direct comparison with non-slit-based irrigation catheter (0.71% vs. 0.08%; p = 0.009). Slit-based irrigation catheters were highly effective in preventing procedure-related ischemic complications., Competing Interests: The authors have declared that no competing interests exist.

Background: Persistent atrial fibrillation (AF) can change to paroxysmal AF after antiarrhythmic drug medication and cardioversion. We investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in those patient groups., Methods: We prospectively randomized 114 patients with persistent AF to paroxysmal AF (men, 75%; 59.8±9.9 years old) to circumferential pulmonary vein isolation (CPVI) alone group (n=57) and additional POBI group (n=57). Primary end point was AF recurrence after a single procedure, and secondary end points were recurrence pattern, cardioversion rate, and response to antiarrhythmic drugs., Results: After a mean follow-up of 23.8±10.2 months, the clinical recurrence rate did not significantly differ between the CPVI alone and additional POBI group (31.6% versus 28.1%; P =0.682; log-rank P =0.729). The recurrences as atrial tachycardias (5.3% versus 12.3%; P =0.134) and cardioversion rates (5.3% versus 10.5%; P =0.250) were not significantly different between the CPVI and POBI groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 52.6% of CPVI group and 59.6% of POBI group ( P =0.450). No significant difference was found in major complication rates between the two groups (5.3% versus 1.8%; P =0.618), but the total ablation time was significantly longer in the POBI group (4187±952 versus 5337±1517 s; P <0.001)., Conclusions: In patients with persistent AF converted to paroxysmal AF by antiarrhythmic drug, the addition of POBI to CPVI did not improve the rhythm outcome of catheter ablation or influence overall safety, while leading to longer ablation time. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02176616.

Atrio-esophageal fistula (AEF) is one of the most devastating complication of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) and surgical repair is strongly recommended. However, optimal surgical approach remains to be elucidated. We retrospectively reviewed AEF cases that occurred after RFCA in a single center and evaluated the clinical results of different surgical approach. Surgical or endoscopic repair was attempted in five AF patients who underwent RFCA. Atrio-esophageal fistula and mediastinal infection was not controlled in the patient who underwent endoscopic repair eventually died. Lethal cerebral air embolism occurred two days after surgery in a patient who underwent esophageal repair only. Primary surgical repair of both the left atrium (LA) and esophagus was performed in the remaining three patients. Among these three patients, two underwent external LA repair and the remaining had internal LA repair via open-heart surgery. External repair of the LA was unsuccessful and one patient dies and another had to undergo second operation with internal repair of the LA. The patient who underwent internal LA repair during the first operation survived without additional surgery. Furthermore, we applied veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with artificial induction of ventricular fibrillation in this patient to prevent air and septic embolism and she had no neurologic sequelae. In summary, surgical correction can be considered preferentially to correct AEF. Open-heart surgical repair of LA from the internal side seems to be an acceptable surgical method. Application of VA-ECMO with artificial induction of ventricular fibrillation might be effective to prevent air and septic embolism.

Background: The role of catheter ablation as an adjunct and alternative to ICD implantation is not known in patients at risk for recurrent ventricular tachycardia (VT) and sudden cardiac death (SCD) across Asia. Patients with nonischemic etiologies of cardiomyopathy, which are highly prevalent in Asia, have not been previously enrolled in randomized trials of VT ablation., Objective: To evaluate whether preemptive catheter ablation in patients with monomorphic VT and an indication for ICD implantation results in improved clinical outcomes compared to ICD implantation with standard medical therapy alone. To examine the natural history of ablation outcomes in the absence of background ICD therapy in patients that refuse randomization., Methods: The PAUSE-SCD study (NCT02848781) is a prospective, multi-center, randomized controlled trial enrolling patients with structural heart disease (EF < 50%) with an indication for ICD implantation. Patients are randomized in a 1:1 fashion to two treatment arms: ICD with ablation and ICD with standard medical therapy alone. A prospective registry cohort was designed to follow the outcomes of patients who refuse ICD and randomization but elect to receive catheter ablation as primary therapy. The primary endpoint is defined as a composite of recurrent VT, cardiovascular rehospitalization, and death. Pre-specified secondary endpoints include each of the individual components of the primary endpoint in addition to comparison between randomized and registry patients., Conclusion: The PAUSE-SCD study is a prospective, multi-center, randomized, and controlled trial examining the impact of preemptive catheter ablation on cardiovascular outcomes in patients with an indication for ICD at risk for recurrent VT and SCD. It represents the first multi-center VT ablation study in Asia, with a design intended to provide insights into the role of both ICD and ablation therapy in a predominantly nonischemic population.

Introduction: Risk factors of embolic stroke (ES) after atrial fibrillation (AF) ablation have not been fully elucidated especially among the Asian subjects, particularly regarding epicardial adipose tissue (EAT) in cardiac imaging. We aimed to assess the incidence of ES during a long-term follow-up period after AF ablation and to identify the risk factors associated with postablation ES, specifically focusing on EAT., Methods and Results: We enrolled patients who experienced postablation ES and control subjects from a consortium of AF ablation registries from three institutes in Korea. EAT was assessed using multislice computed tomography before AF ablation. A total of 3464 patients who underwent AF ablation were recruited and followed-up. During a follow-up of 47.2 ± 36.4 months, ES occurred in 47 patients (1.36%) with a CHA 2 DS 2 -VASc score of 1.48 ± 1.39 and the overall annual incidence of ES was 0.34%. Compared with the control group (n = 190), the ES group showed significantly higher prior thromboembolism (TE) and AF recurrence rates, larger left atrium size, lower creatinine clearance rate (CCr), and greater total and peri-atrial EAT volume. Multivariate regression analysis demonstrated larger peri-atrial EAT volume (hazards ratio, 1.065; 95% confidence interval, 1.005-1.128), in addition to a prior history of TE and lower CCr, was independently associated with postablation ES. When a cut-off value of peri-atrial EAT volume of ≥20.15 mL was applied, patients with smaller peri-atrial EAT volume showed significantly higher ES-free survival., Conclusion: Larger peri-atrial EAT volume, in addition to prior TE and lower CCr, was independently associated with postablation ES regardless of AF recurrence and CHA 2 DS 2 -VASc score. (ClinicalTrials.gov number, NCT03479073)., (© 2019 Wiley Periodicals, Inc.)

Objectives: This study explored whether complete electrical isolation of the left atrial (LA) posterior wall improves the rhythm outcome of catheter ablation of persistent atrial fibrillation (AF)., Background: Although the STAR AF2 (Substrate and Trigger Ablation for Reduction of Atrial Fibrillation Trial Part II) proved no additional benefit of empirical extra-pulmonary vein (PV) LA ablation, the long-term recurrence rate after circumferential PV isolation (CPVI) alone remains high., Methods: We randomly assigned 217 patients with persistent AF (83.1% men, age 58.7 ± 10.8 years, 73.3% long-standing persistent AF) to ablation with CPVI alone (CPVI group) or CPVI with a POsterior wall Box Isolation (POBI group). The endpoint of the POBI group was the elimination of the posterior atrial potentials by roof and posterior inferior lines and touch-up focal ablation., Results: After a mean follow-up of 16.2 ± 8.8 months, the clinical recurrence rate did not significantly differ between the 2 groups (23.8% vs. 26.5%; p = 0.779) in the CPVI and POBI groups. The recurrence rate for atrial tachycardias (16.0% vs. 11.1%; p = 0.913) and cardioversion rates (6.7% vs. 13.7%; p = 0.093) to control clinical recurrences also did not significantly differ between the 2 groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 50.5% and 55.9% in the CPVI and POBI groups, respectively (p = 0.522). No significant difference was found in the major complication rates between the 2 groups, but the total ablation time was significantly longer in the POBI group (4,289 ± 1,837 s vs. 5,365 ± 2,358 s; p < 0.001)., Conclusions: In patients with persistent AF, an empirical complete POBI did not improve the rhythm outcome of catheter ablation or influence the type of recurrent atrial arrhythmia. (Comparison of Circumferential Pulmonary Vein Isolation Alone Versus Linear Ablation in Addition to Circumferential Pulmonary Vein Isolation for Catheter Ablation in Persistent Atrial Fibrillation: Prospective Randomized Controlled Trial; NCT02721121)., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Although the hemodynamic burden and structural substrate contribute to valvular atrial fibrillation (VAF) mechanisms, the role of catheter ablation has rarely been reported. We investigated the clinical characteristics, mapping findings, and long-term rhythm outcomes after catheter ablation of hemodynamically corrected VAF., Methods: We compared 77 patients with VAF (46.8% male, 52.7±8.8 years old, 46.8% paroxysmal AF, 24.7% with maze procedures) and 2244 patients with non-VAF (NVAF) who underwent catheter ablation. Among the VAF patients, 44 (57.1%) had mechanical valve AF (MV-AF) and 33 (42.9%) underwent a prior mitral valvuloplasty (MVP-AF). We analyzed the catheter ablation rhythm outcomes for MV-AF and MVP-AF., Results: The left atrial (LA) diameter was greater (p<0.001), LA voltage lower (p<0.001), and procedure-related complication rate higher (mainly sinus node dysfunction, p=0.004) for VAF than NVAF. During 70.2±1.8 months of follow-up, the rhythm outcome of VAF did not significantly differ from that of NVAF after catheter ablation (log rank p=0.399), even after excluding patients with maze procedures (log rank p=0.629). The clinical recurrence rates did not differ between the MV-AF and MVP-AF groups (log rank p=0.244), or between patients with prior maze procedures and those without (log rank p=0.651). The main conduction recovery sites of previous maze procedures were the perimitral (84.2%) and cavotricuspid isthmus (84.2%) areas, and recurrence mechanisms were macroreentry (63.2%) and focal/microreentry (26.3%) at scar border zones., Conclusions: Although hemodynamically corrected VAF was associated with advanced LA remodeling, the rhythm outcome did not significantly differ from that of NVAF after catheter ablation., (Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.)

Aims: Although a recent expert consensus statement has recommended periprocedural uninterrupted (UI) non-vitamin K antagonist oral anticoagulants (NOACs) during catheter ablation of atrial fibrillation (AF) as a Class I indication, there have been no clear randomized trials. We investigated the safety and efficacy of UI, procedure day single-dose skipped (SDS), and 24-hour skipped (24S) NOACs in patients undergoing AF ablation., Methods and Results: In this prospective, open-label, randomized multicentre trial, 326 patients (75% male, 58 ± 11 years old) scheduled for AF catheter ablation were randomly assigned in a 1:1:1 ratio to UI, SDS, and 24S at three tertiary hospitals. Bridging with low molecular weight heparin was carried out in the patients with persistent AF who were assigned to the 24S group. Dabigatran, rivaroxaban, and apixaban were assigned in order after randomization. The primary endpoint was the incidence of bleeding events within 1 month after ablation. The secondary endpoints included thrombo-embolic and other procedure-related complications. The intra-procedural heparin requirement was higher in the 24S group than others (P < 0.001), and the mean activated clotting time was comparable among the groups (P = 0.139). The incidence of major bleeding up to 1 month after ablation and a post-procedural reduction in the haemoglobin levels did not significantly differ among the treatment groups and different NOACs (P > 0.05). There were no fatal events or thrombo-embolic complications in all the three groups., Conclusion: In patients undergoing AF ablation, UI NOACs and SDS or double dose skipped NOACs had a comparable efficacy and safety, regardless of the type of NOAC., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Ischemic stroke after radiofrequency catheter ablation (RFCA) in atrial fibrillation (AF) patients is a great challenge for electrophysiologists. We performed this retrospective study to evaluate clinical and echocardiographic characteristics associated with increased risk of ischemic stroke following RFCA. A total of 2,352 consecutive patients with AF who underwent first-time RFCA were analyzed. Among 10,023 patient*year follow up, ischemic stroke occurred in 49 patients (0.49% per year). Late recurrence after last RFCA was significantly associated with ischemic stroke (3.8% vs. 12.9%, p < 0.001). Old age (≥60 years old) (3.2% vs. 15.4%, p = 0.001), non-paroxysmal AF (hazard ratio = 1.91, p = 0.024), left atrium (LA) size ≥45.0 mm (6.6% vs. 11.7%, p < 0.001), E over E' ≥10 (4.3% vs. 20.1%, p < 0.001), dense spontaneous echo contrast (SEC) (5.2% vs. 19.0%, p = 0.006), and decreased left atrial appendage (LAA) flow velocity (≤40 cm/sec) (4.1% vs. 10.8%, p < 0.001) were also associated with increased risk of ischemic stroke. The REVEEAL score derived from the risk factors identified in this study was superior to CHA 2 DS 2 -VASc score (p < 0.001) for the prediction of ischemic stroke. In conclusion, the risk factors for ischemic stroke in post-RFCA AF patients are not identical to RFCA naive AF patients and different approach to stratify the risk of ischemic stroke is needed.

The benefits of radiofrequency catheter ablation (RFCA) for patients with atrial fibrillation (AF) significantly decrease with late recurrence (LR). We aimed to develop a scoring system to identify patients at high and low risk for LR following RFCA, based on a comprehensive evaluation of multiple risk factors for AF recurrence, including echocardiographic parameters. We studied 2,352 patients with AF undergoing first-time RFCA in a single institution. The LR-free survival rate up to 5 years was measured using a Kaplan-Meier analysis. The influence of clinical and echocardiographic parameters on LR was calculated with a Cox-regression analysis. Duration of AF ≥4 years (hazard ratio [HR] = 1.75; p < 0.001), non-paroxysmal AF (HR = 3.18; p < 0.001), and diabetes (HR = 1.34; p = 0.015) were associated with increased risk of LR. Left atrial (LA) diameter ≥45 mm (HR = 2.42; p < 0.001), E/e' ≥ 10 (HR = 1.44; p < 0.001), dense SEC (HR = 3.30; p < 0.001), and decreased LA appendage flow velocity (≤40 cm/sec) (HR = 2.35; p < 0.001) were echocardiographic parameters associated with increased risk of LR following RFCA. The LR score based on the aforementioned risk factors could be used to predict LR (area under curve = 0.717) and to stratify the risk of LR (HR = 1.45 per 1 point increase in the score; p < 0.001). In conclusion, LR after RFCA is affected by multiple clinical and echocardiographic parameters. This study suggests that combining these multiple risk factors enables the identification of patients with AF at high or low risk for having arrhythmia recurrence.

Atrial fibrillation (AF) is the most common arrhythmia associated with the risk of morbidity and mortality in clinical patients. AF is considered as an arrhythmia type that develops and progresses through close connection with cardiac structural arrhythmogenic substrates. Since the introduction of catheter ablation-mediated electrical isolation of arrhythmogenic substrates, cardiac imaging indicates improved treatment outcome and prognosis with appropriate candidate selection, ablation catheter guidance, and post-ablation follow-up. Currently, cardiac computed tomography (CCT) and cardiovascular magnetic resonance (CMR) imaging are essential in the case management of AF at both pre-and post-procedural stages of catheter ablation. In this review, we discuss the roles and technical considerations of CCT and CMR imaging in the management of patients with AF undergoing catheter ablation., Competing Interests: The authors have no potential conflicts of interest to disclose., (Copyright © 2019 The Korean Society of Radiology.)

Purpose: Catheter ablation for atrial fibrillation (AF) requires heavy anticoagulation and uncomfortable post-procedural hemostasis. We compared patient satisfaction with and the safety of unilateral groin (UG) puncture-single trans-septal (ST) ablation with conventional bilateral groin (BG) puncture-double trans-septal (DT) ablation in paroxysmal AF patients., Materials and Methods: We enrolled 222 patients with paroxysmal AF (59.4±10.7 years old) who were randomized in a 2:1 manner into UG-ST ablation (n=148) and BG-DT ablation (n=74) groups. If circumferential pulmonary vein isolation could not be achieved after three attempts of touch-up ablation in the UG-ST group, the patient was crossed over to BG-DT by performing a left groin puncture., Results: Ten patients in the UG-ST group (6.8%) required crossover to the BG-DT approach. There were no significant differences in procedure time ( p =0.144) and major complications rate ( p >0.999) between the UG-ST and BG-DT groups. Access site pain ( p =0.014), back pain ( p =0.023), and total pain ( p =0.015) scores were significantly lower for the UG-ST than BG-DT group as assessed by the Visual Analog Scale. Over 20.2±8.7 months of follow up, there was no difference in AF recurrence free-survival rates between the two groups (Log rank, p =0.984)., Conclusion: UG-ST AF ablation is feasible and safe, and was found to significantly reduce post-procedural hemostasis-related discomfort, compared to the conventional DT approach, in patients with paroxysmal AF., Competing Interests: The authors have no potential conflicts of interest to disclose., (© Copyright: Yonsei University College of Medicine 2019.)

Aims: Findings regarding efficacy of substrate modification for non-paroxysmal atrial fibrillation (AF) are inconsistent. We prospectively compared clinical outcomes of complex fractionated atrial electrogram (CFAE)-guided focal ablation (CFA) and CFAE-guided linear ablation (CLA) in patients with non-paroxysmal AF., Methods and Results: We randomized 150 patients with non-paroxysmal AF into CFA and CLA groups in a 1:1 ratio. Complex fractionated atrial electrogram distribution was evaluated using an automated algorithm of a three-dimensional mapping system. After pulmonary vein isolation (PVI), CFAE-guided ablation was performed in the left atrium and then in the right atrium (RA). When compared with conventional CFA, CLA was performed based on conventional lines, with additional lines. Atrial fibrillation was not induced after PVI alone or with cavotricuspid isthmus ablation in 20.7% of patients. To achieve the endpoint, additional CFAE-guided RA ablation was required in 42.7% and 36.0% of patients undergoing CFA and CLA, respectively (P = 0.403). Atrial fibrillation was terminated during CFAE-guided ablation in 72.9% and 75.0% of patients undergoing CFA and CLA, respectively (P = 0.792). Termination of atrial tachycardia (AT) or non-inducibility of AF/AT was achieved in 61.3% and 68.0% of patients undergoing CFA and CLA, respectively (P = 0.393). The CLA group showed decreased 1-year freedom from AF/AT recurrence (60.0%, CFA vs. 47.3%, CLA; log rank P = 0.085), but no significant difference throughout the follow-up (22.2 ± 21.0 months) (67.1%, CFA vs. 68.9%, CLA; log rank P = 0.298)., Conclusion: Long-term efficacy of CFAE-guided ablation was unaffected by the ablation technique in patients with non-paroxysmal AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Background: Electrical isolation of the left atrial appendage (LAA) is associated with a lower rate of atrial fibrillation (AF) recurrence in patients undergoing radiofrequency catheter ablation. However, LAA isolation can significantly impair LAA contractility., Objective: This study was performed to evaluate whether electrical isolation of the LAA is associated with an increased risk of ischemic stroke or transient ischemic attack (TIA)., Methods: Consecutive patients with AF undergoing radiofrequency catheter ablation at Korea University Medical Center Anam Hospital were analyzed., Results: Of 2352 patients, 39 (1.7%) had LAA isolation. Patients with LAA isolation had a significantly higher rate of ischemic stroke or TIA than did those without LAA isolation (log-rank, P < .001; hazard ratio 23.6; P < .001). There were significant differences in the baseline characteristics of the 2 groups, including type of AF (34 [87.2%] and 911 [39.4%] patients with and without LAA isolation had nonparoxysmal AF, respectively). After multivariate adjustment, LAA isolation was found to be a significant risk factor for ischemic stroke or TIA (adjusted hazard ratio 11.3; P < .001). Propensity score-matched analysis also revealed an increased risk of ischemic stroke or TIA in patients with LAA isolation compared with those without LAA isolation (log-rank, P = .001). The LAA flow velocity of post-LAA isolation status was not significantly different between patients who did and did not experience ischemic stroke or TIA (30.3 ± 17.7 cm/s vs 33.9 ± 17.9 cm/s; P = .608)., Conclusion: A significantly increased risk of ischemic stroke or TIA was observed in patients with electrical isolation of the LAA. In addition, postisolation LAA flow velocity is not a reliable marker to predict future ischemic events., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The electrophysiological features and roles of persistent left superior vena cava (PLSVC) in supraventricular tachycardia (SVT) are not known., Objective: The purpose of this study was to elucidate the electrophysiological features and roles of PLSVC in patients with SVT., Methods: We included 37 patients with PLSVC (mean age 43.5 ± 17.1 years; 35.1% men) and 510 patients without PLSVC (mean age 43.9 ± 18.8 years; 48.2% men) who underwent an electrophysiology study for SVT. The number of induced tachycardias, location of the slow pathway (SP) or accessory pathway (AP), and radiofrequency catheter ablation (RFCA) outcomes were compared between patients with and without PLSVC. During RFCA of the left AP, a coronary sinus (CS) catheter was placed into the left superior vena cava (left superior vena cava group) or the great cardiac vein (great cardiac vein group). The RFCA outcomes were compared between the groups., Results: In patients with PLSVC, 40 tachycardias were induced: atrioventricular nodal reentrant tachycardia (AVNRT) (n = 19), atrioventricular reentrant tachycardia (n = 17), and focal atrial tachycardia (n = 4). Among patients with AVNRT, an SP in the CS was significantly more frequent in patients with PLSVC than in those without PLSVC (47.4% vs 3.8%; P < .001). In patients with the left AP, the number of RFCA attempts and recurrence were lower in the great cardiac vein group than in the left superior vena cava group., Conclusion: An SP in the CS is prevalent in patients with AVNRT and PLSVC. It is useful to place a CS catheter into the great cardiac vein in patients with a left AP and PLSVC., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: Radiofrequency catheter ablation (RFCA) in atrial fibrillation (AF) patients can cause various complications and atrioesophageal (AE) fistula is one of the most catastrophic complications of RFCA., Methods and Results: RFCA registries from 3 cardiovascular centers in the Republic of Korea consisted of 5721 patients undergoing 6724 procedures. Before undergoing RFCA, patients underwent either computed tomography or magnetic resonance imaging. We evaluated clinical, anatomical, and procedural characteristics of patients who developed AE fistula after RFCA. A total of 10 patients developed AE fistula after RFCA (0.15% per procedure). All AE fistulas occurred during first-time RFCA. Eight patients died and mortality rate was 80.0%. No patients had any gastrointestinal symptom at the time of discharge and mean duration time from RFCA to symptom onset was 23.4 days. Six patients (60.0%) had paroxysmal AF. Substrate modification in addition to pulmonary vein isolation was performed in 4 patients (40.0%). Patients with old age, low body weight, and high CHA 2 DS 2 -VASc score were at increased risk of AE fistula. Baseline imaging evaluation revealed that esophagus had closest contact with LA posterior wall near left inferior pulmonary vein rather than left superior pulmonary vein and all documented AE fistulas were located near left inferior pulmonary vein., Conclusion: Posterior wall of LA near left inferior pulmonary vein was the most vulnerable location for AE fistula. Pulmonary vein isolation was the main lesion set associated with AE fistula and old age, low body weight, and high CHA 2 DS 2 -VASc score were significant risk factors for AE fistula., (© 2018 Wiley Periodicals, Inc.)

The interruption of oral anticoagulation therapy (OAC) after CA of atrial fibrillation (AF) is controversial. The purpose of this study was to evaluate the relationship between successful long-term outcomes of catheter resection and SR maintenance and ischemic stroke risk in Korea. We studied 1,548 consecutive patients who were followed up for more than 2 years after CA of AF. We investigated the incidence of ischemic stroke during long-term follow-up. Compared to the AF recurrence group (n = 619), the sinus rhythm (SR) maintenance group (n = 929) had more paroxysmal AF (74.6% versus 44.4%, p<0.001), smaller LA size (39.9±5.7mm versus 42.3±6.0mm, p<0.001), and younger age (54.2±10.9 years versus 56.4±10.6 years, p<0.001). However, CHA2DS2-VASc scores were not significantly different between the two groups (0.9 vs. 1.1, p = 0.053). The overall incidence of ischemic stroke during the mean follow-up period of 54 months after CA was 0.6%, and was significantly lower in the SR group than the AF recurrence group (0.3% vs. 1.1%, log-rank test p<0.001). However, in sub-analysis in the SR group, the rate of ischemic stroke was significantly increasing in patients with a CHA2DS2-VASc score ≥ 4 compared to those with a CHA2DS2-VASc score < 4 (4.3% vs. 0.2%, log-rank test p<0.001). In conclusion, this long-term follow-up data in patients with AF who underwent successful CA showed that SR maintenance was correlated with a lower rate of ischemic stroke in Korea. However, it was only observed in patients with CHA2DS2-VASc score ≤3., Competing Interests: The authors have declared that no competing interests exist.

Background: Atrial fibrillation (AF) frequently coexists with heart failure (HF) with reduced ejection fraction (EF). This meta-analysis compared AF control strategies, that is, rhythm vs. rate, and catheter ablation (CA) vs. anti-arrhythmic drugs (AAD) in patients with AF combined with HF.Methods and Results:The MEDLINE, EMBASE, and CENTRAL databases were searched, and 13 articles from 11 randomized controlled trials with 5,256 patients were included in this meta-analysis. The outcomes were echocardiographic parameters (left ventricular EF, LVEF), left atrial (LA) size, and left ventricular end-systolic volume, LVESV), clinical outcomes (mortality, hospitalization, and thromboembolism), exercise capacity, and quality of life (QOL). In a random effects model, rhythm control was associated with higher LVEF, better exercise capacity, and better QOL than the rate control. When the 2 different rhythm control strategies were compared (CA vs. AAD), the CA group had significantly decreased LA size and LVESV, and improved LVEF and 6-min walk distance, but mortality, hospitalization, and thromboembolism rates were not different between the rhythm and rate control groups., Conclusions: In AF combined with HF, even though mortality, hospitalization and thromboembolism rates were similar, a rhythm control strategy was superior to rate control in terms of improvement in LVEF, exercise capacity, and QOL. In particular, the CA group was superior to the AAD group for reversal of cardiac remodeling.

Background: There is a controversy as to whether catheter ablation should be the first-line therapy for tachycardia-bradycardia syndrome (TBS) in patients with atrial fibrillation (AF)., Methods: We aimed to investigate long-term clinical outcomes of catheter ablation in patients with TBS and AF. Among 145 consecutive patients who underwent catheter ablation of AF with TBS, 121 patients were studied., Results: Among 121 patients, 11 (9.1%) received implantation of a permanent pacemaker during a mean 21 months after ablation. Length of pause on termination of AF was significantly greater in patients who received pacemaker implantation after ablation than those who underwent ablation only (7.9 ± 3.5 vs. 5.1 ± 2.1 s, p < 0.001). Using a multivariate model, a long pause of 6.3 s or longer after termination of AF was associated with the requirement to implant a permanent pacemaker after ablation (HR 1.332, 95% CI 1.115-1.591, p = 0.002)., Conclusion: This study suggests that, in patients with AF predisposing to TBS, long pause on termination of AF predicts the need to implant a permanent pacemaker after catheter ablation.

Atrial fibrillation (AF) is known to cause adverse remodeling of left atrium (LA). Radiofrequency catheter ablation (RFCA) of AF is associated with decrease in LA volume. However, the impact of RFCA on left atrial appendage (LAA) volume and hemodynamic function is not fully understood. We analyzed 123 patients who underwent cardiac magnetic resonance imaging (MRI) evaluation before and after RFCA in Korea University Anam Hospital. LA and LAA volume were measured before and after RFCA based on cardiac MRI. Baseline LA volume was 99.5 ± 38.4 cm 3 and decreased to 74.6 ± 28.5 cm 3 after RFCA (p < 0.001). LA diameter measured with transthoracic echocardiography was also decreased after RFCA (43.3 ± 6.2 mm at baseline and 39.9 ± 5.9 mm at follow up; p < 0.001). However, LAA volume was significantly increased after RFCA (19.4 ± 8.5 cm 3 at baseline and 23.7 ± 13.3 cm 3 at follow up; p < 0.001). Total ablation time and additional substrate modification was associated with change in LA volume. After RFCA, average LAA velocity measured by transesophageal echocardiography was increased to 51.0 cm/sec from 41.1 cm/sec (p < 0.001). In conclusion, LAA volume was increased after RFCA in contrast to LA volume. Our data raise a concern about worsening hemodynamics of LA and LAA following RFCA and long term clinical significance of enlarged LAA after RFCA needs further evaluation.

Background: Pulmonary vein isolation (PVI) is effective for maintenance of sinus rhythm in 50% to 75% of patients with paroxysmal atrial fibrillation, and it is not uncommon for patients to require additional ablation after PVI. We prospectively evaluated the relative effectiveness of 2 post-PVI ablation strategies in paroxysmal atrial fibrillation., Methods and Results: A total of 500 patients (mean age, 55.7±11.0 years; 74.6% male) were randomly assigned to undergo ablation by 2 different strategies after PVI: (1) elimination of non-PV triggers (group A, n=250) or (2) stepwise substrate modification including complex fractionated atrial electrogram or linear ablation until noninducibility of atrial tachyarrhythmia was achieved (group B, n=250). During a median follow-up of 26.0 months, 75 (32.2%) patients experienced at least 1 episode of recurrent atrial tachyarrhythmia after the single procedure in group A compared with 105 (43.8%) patients in group B ( P value in log-rank test of Kaplan-Meier analysis: 0.012). Competing risk analysis showed that the cumulative incidence of atrial tachycardia was significantly higher in group B compared with group A ( P =0.007). With the exception of total ablation time, there were no significant differences in fluoroscopic time or procedure-related complications between the 2 groups., Conclusions: Elimination of triggers as an end point of ablation in patients with paroxysmal atrial fibrillation decreased long-term recurrence of atrial tachyarrhythmia compared with a noninducibility approach achieved by additional empirical ablation. The post-PVI trigger test is thus a better end point of ablation for paroxysmal atrial fibrillation., (© 2018 American Heart Association, Inc.)

Background: Circumferential pulmonary vein isolation (CPVI) alone or combined with adjuvant substrate modifications is unsatisfactory for atrial fibrillation (AF) control in nonparoxysmal AF patients. Ablation targeting the fibrotic areas after CPVI (STABLE-SR [Electrophysiological Substrate Ablation in the Left Atrium During Sinus Rhythm]) is a newly evolved substrate modification strategy., Methods and Results: In this multicenter, randomized clinical trial, 229 symptomatic nonparoxysmal AF patients were 1:1 randomized to STABLE-SR group (n=114) or conventional STEPWISE group (n=115). In the STABLE-SR group, after CPVI, cavotricuspid isthmus ablation and cardioversion to sinus rhythm, left atrial high-density mapping was performed. Areas with low-voltage and complex electrogram were further homogenized and eliminated, respectively. Dechanneling would be done if necessary. In the STEPWISE group, additional linear lesions and defragmentation were performed.The primary end point was freedom from documented atrial tachyarrhythmias for ≥30 s after a single ablation procedure without antiarrhythmic medications at 18 months. At 18 months, 74.0% of the patients in the STABLE-SR group and 71.5% in the STEPWISE group (hazard ratio, 0.78; 95% confidence interval, 0.47-1.29; P =0.325) achieved success according to intention-to-treat analysis. However, less procedure time (186.8±52.7 versus 210.5±48.0 minutes, P <0.001), reduced post-CPVI fluoroscopic time (11.0±7.8 versus 13.7±8.9 minutes, P =0.006), and shorter energy delivery time (60.1±25.1 versus 75.0±24.3 minutes, P <0.001) were observed in the STABLE-SR group compared with the STEPWISE group., Conclusions: STABLE-SR is a simplified, personalized, and effective ablation strategy in nonparoxysmal AF patients. More importantly, over 50% nonparoxysmal AF patients do not need further ablation beyond CPVI and therefore can avoid excessive ablation., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01761188., (© 2017 American Heart Association, Inc.)

Aims: Controversy on the optimal ablation strategy for persistent atrial fibrillation (AF) exists with limited work evaluating a strategy of pulmonary vein isolation (PVI) alone when AF terminates during PVI. Thirty-five patients had AF termination during PVI in the Modified Ablation Guided by Ibutilide Use in Chronic Atrial Fibrillation (MAGIC-AF; ClinicalTrials.gov number: NCT01014741) study. The objective of the current study is to report the 1-year outcome after PVI alone in this unique patient group., Methods and Results: The 1-year single procedure freedom from atrial arrhythmia off anti-arrhythmic drugs was reported for the 35 patients in the MAGIC-AF study with persistent AF termination during or upon completion of PVI. Freedom from recurrent atrial arrhythmia was achieved in 60% of patients where AF terminated during PVI. Cavotricuspid isthmus flutter was common when AF terminated to a macro re-entrant flutter during PVI, and responsible for 92% of all flutter circuits with AF termination., Conclusions: Persistent AF termination during PVI may identify a subgroup of patients who experience a similar long-term clinical outcome with PVI ablation alone when compared with other more extensive persistent AF ablation strategies. Pulmonary vein isolation alone may be an appropriate tactic in this subgroup of persistent AF patients., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Background: Atrial fibrillation (AF) type can vary depending on condition and timing, and some patients who initially present with persistent AF may be changed to paroxysmal AF after antiarrhythmic drug medication and cardioversion. We investigated whether circumferential pulmonary vein isolation (CPVI) alone is an effective rhythm control strategy in patients with persistent AF to paroxysmal AF., Methods and Results: We enrolled 113 patients with persistent AF to paroxysmal AF (male 75%, 60.4±10.1 years old) who underwent catheter ablation for nonvalvular AF at 3 tertiary hospitals. The participants were randomly assigned to 2 groups: CPVI alone (n=59) or CPVI plus linear ablation (CPVI+Line; posterior box+anterior line, n=54). Compared with the CPVI+Line, CPVI alone required shorter procedure (187.2±58.0 versus 211.2±63.9 min; P =0.043) and ablation times (4922.1±1110.5 versus 6205.7±1425.2 s; P <0.001) without difference in procedure-related major complication (3% versus 2%; P =0.611). Antiarrhythmic drug utility rates after ablation were not different between the 2 groups (22% versus 30%; P =0.356). Overall, AF-free survival (log-rank; P =0.206) and AF and antiarrhythmic drug-free survival (log-rank; P =0.321) were not different between groups., Conclusions: CPVI alone is an effective rhythm control strategy with a shorter procedure time in persistent AF patients converted to paroxysmal AF compared with CPVI with linear ablation., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02176616., (© 2017 American Heart Association, Inc.)

Background: Functional remodeling of left atrium (LA) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has not been fully elucidated. This study aimed to determine the impact of RFCA on LA transport function in patients who maintained sinus rhythm (SR) after AF ablation., Methods and Results: A total of 96 patients (paroxysmal AF [PAF] = 52) who maintained SR during 1 year after AF ablation were enrolled. Multislice computed tomography was performed to determine LA volume (LAV) and LA emptying fraction (LAEF) at pre-RFCA and 1-year post-RFCA. Creatine kinase-MB (CK-MB) and troponin-T levels were analyzed 1-day post-RFCA. At 1-year post-RFCA, mean LAV and LAEF decreased in overall patients. Based on LAEF change (ΔLAEF) cutoff of 5.0%, LAEF reduced in 41 patients (worsened group) and improved or showed no change in 55 patients (preserved group). Compared with preserved group, worsened group had a higher proportion of PAF, higher levels of CK-MB and troponin-T, and additional LA ablation. ΔLAEF was inversely correlated with CK-MB and troponin-T levels. Subgroup analysis showed that LAEF significantly decreased in PAF patients who underwent additional LA ablation. Multivariate analysis revealed that high baseline LAEF and additional LA ablation were independent predictors for worsened LAEF., Conclusions: Although SR was maintained for 1 year after AF ablation, LAEF as well as LAV decreased. The extent of LAEF deterioration was significantly associated with the amount of iatrogenic myocardial damage. Our data indicate that extensive atrial ablation may lead to LA functional deterioration, especially in patients with PAF., (© 2016 Wiley Periodicals, Inc.)

Background: The left atrial appendage (LAA) can be a source of atrial fibrillation (AF) triggering or a part of reentry. We sought to determine the characteristics and clinical outcomes of patients with LAA potential delay including electrical isolation (LAAEI) following LA anterior wall (LAAW) ablation for AF., Methods: LAAW ablation cases were collected from among 846 patients who underwent catheter ablation (CA). A total of 89 patients were enrolled; they were divided into three groups according to the extent of LAA potential injury. The ejection fractions (EFs) of the LAA and LA were measured by means of LA angiograms., Results: The mean age of all patients was 56.2 ± 10.7 years (74 males, 83 %). In 47 of the 89 patients, an LAA potential delay was identified after LAAW ablation (group 2). LAAEI was seen in 18 patients (group 3). In the remaining 24 patients, there was no LAA potential delay or LAAEI (group 1). The mean EF decreased significantly after CA in group 3 (P < 0.001). At 21-month follow-up, three patients (17 %) in group 3 had recurrence compared with 11 (42 %) in group 2 and 12 (46 %) in group 3 (P = 0.028). In multivariate analysis, diabetes mellitus and LAA potential delay were independent predictors of AF recurrence (P = 0.021, P = 0.008, respectively)., Conclusion: Ablation of the LA anterior wall near the insertion of Bachmann's bundle and the neck of the LAA resulting in LAA potential delay or electrical isolation is effective in preventing recurrence of atrial fibrillation.

Introduction: Atrial fibrillation (AF) is a common manifestation in cases of hypertrophic cardiomyopathy (HCM). Catheter ablation (CA) for AF in patients with asymmetric septal HCM (SeHCM) is selectively effective and often needs a repeat procedure. Apical HCM (ApHCM) has a better prognosis than SeHCM. However, the outcome of CA for AF in patients with ApHCM is unclear., Methods and Results: Eighteen patients with ApHCM (ApHCM group) and 13 SeHCM patients (SeHCM group) underwent CA for AF. Ninety sex-, age-, and AF type-matched non-HCM patients who underwent CA for AF were selected as controls (5 controls for each ApHCM patient). During a median follow-up of 44.7 ± 30.8 months, 50% of the patients remained free from AF/atrial tachycardia (AT) in the ApHCM group. The ApHCM patients displayed enlarged left atrial (LA) diameter (47.1 ± 6.0 mm vs. 42.4 ± 5.5 mm, P = 0.006) and increased E/Ea ratio (13.5 ± 4.4 vs. 9.1 ± 3.1, P < 0.001) as compared to the control group. In contrast, the mean LA diameter and E/Ea ratio of the ApHCM group were not different than those of the SeHCM group. The overall freedom from AF/AT in the ApHCM group was significantly worse than in the control group (log rank P = 0.028), but there was no difference between the ApHCM and SeHCM groups (P = 0.831). High LA diameter index ≥25 mm/m(2) (HR 12.8, 95% CI [1.2-142.1]; P = 0.037) was an independent predictor of AF/AT recurrence among patients with ApHCM., Conclusion: Long-term outcome of CA for AF was worse in patients with ApHCM, as compared to controls, but was similar to patients with SeHCM., (© 2016 Wiley Periodicals, Inc.)

Aims: The interatrial septal thickness (IAST) reflects the changes of the atrial wall in patients with atrial fibrillation (AF). Complex fractionated atrial electrograms (CFAEs) were consistently positioned on the interatrial septum, especially in the remodelled left atrium (LA). We sought to characterize the relationship between IAST and LA CFAE area, as well as the acute procedural and clinical outcomes of catheter ablation in persistent AF patients., Methods and Results: This study included 71 patients who underwent catheter ablation for drug-refractory persistent AF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by LA and right atrial CFAE-guided ablation. Interatrial septal thickness was measured 1 cm inferior to the fossa ovalis on cardiac computed tomography (CT). The extent of LA CFAEs was assessed by CFAE area and index (CFAE area/LA surface area × 100). Patients were grouped into tertiles according to the value of IAST. The mean IAST of the first, second, and third tertile was 4.69 ± 0.79, 6.44 ± 0.45, and 9.12 ± 1.42 mm, respectively (P < 0.001). The mean CFAE areas (5.6 ± 6.9, 18.5 ± 20.3, and 24.3 ± 26.6 mm(2), P = 0.005) and CFAE indexes (3.1 ± 4.2, 9.2 ± 10.7, and 11.8 ± 15.3, P = 0.025) in LA were significantly different among the three groups. More patients in the highest IAST tertile did not terminate AF during catheter ablation (12.5% vs. 26.1% vs. 37.5%, P = 0.048)., Conclusions: Interatrial septal thickness measured by cardiac CT is associated with the extent of CFAE area within the LA and is related to acute procedural success of catheter ablation. These findings suggest that IAST reflects the degree of atrial substrate and remodelling in patients with persistent AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Aims: Atrial fibrillation (AF) cycle length (CL) has been demonstrated to be one of the predictors for termination during ablation for AF. We evaluated the AF CL gradient between right atrium (RA) and left atrium (LA) and their mean AF CL in predicting the extent of substrate ablation., Methods and Results: One-hundred and thirty-six patients undergoing first ablation for persistent AF were studied. Stepwise ablation, sequentially in the following order: pulmonary veins (PV), LA, and RA, was performed to achieve AF termination. Stepwise ablation terminated AF in 110 patients (81%). In the AF termination group, AF was terminated by PV isolation (PVI) (Group P), PVI plus LA ablation (Group L), and PVI plus LA plus RA ablation (Group R) in 14 patients (13%), 49 patients (44%), and 47 patients (43%), respectively. Group R had much shorter mean AF CL than Group L (156 ± 18 vs. 174 ± 24 ms, P < 0.001) and mean AF CL in Group L was much shorter than Group P (174 ± 24 vs. 209 ± 36 ms, P = 0.004). The RA to LA AF CL gradient was not significantly different between left-side ablation (Group P + Group L) and additional RA ablation (Group R) (P = 0.177). Mean AF CL >180.50 ms predicted AF termination by PVI (Group P) with 79% sensitivity and 84% specificity while mean AF CL >165.25 ms predicted AF termination by left-side ablation (Group P + Group L) with 67% sensitivity and 75% specificity. After a mean follow-up of 15 ± 7 months, freedom from arrhythmia recurrence was significantly higher in left-side ablation (Group P + Group L) than additional RA ablation (Group R) (P = 0.024)., Conclusion: Baseline mean AF CL may identify the subset of patients in whom persistent AF can be terminated by different extent of substrate ablation, which may in turn predict the chance of recurrence. However, baseline RA to LA AF CL gradient cannot predict the need for additional RA ablation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

A 31-year-old patient previously underwent a Mustard operation presented with palpitations. Atrial tachycardia and paroxysmal atrial fibrillation were documented on the surface electrocardiogram. Under the guidance of a three-dimensional electroanatomic mapping system, ablation of the isolated left-sided pulmonary vein and a cavo-tricuspid isthmus-dependent intra-atrial macro re-entry circuit eliminated atrial tachycardia and paroxysmal atrial fibrillation without the recurrence of atrial tachyarrhythmia.

Left arial (LA) function, defined according to conduit, reservoir and booster functions, is closely linked to left ventricular (LV) mechanics, particularly during diastole. Right ventricular pacing (RVP) is thought to impair LA diastolic restoring forces through alteration of ventricular activation. The aim of this study was to determine whether the LA functional reservoir estimated as the change in mean LA ejection fraction (EF) immediately after RVP, and for the second and for the third beats after RVP, predicts clinical outcome in patients with paroxysmal atrial fibrillation (AF) who have undergone catheter ablation (CA). Data from 155 patients with paroxysmal AF (56.0 ± 10.6 years, M:F = 114:41) were analyzed. All patients underwent LA angiography during RVP. LA EFs were measured at the immediate first (LA EF(1)), second (LA EF(2)) and third beats (LA EF(3)) after RVP, using a right anterior oblique 30° view. During follow-up, AF recurred in 35 patients (22.6 %). Mean LA EF(1) was 37.9 ± .8 % in the AF recurrence group and 48.0 ± 8.6 % in the non-recurrence group (P < 0.001). Mean LA EF(2) and LA EF(3) were also lower in the AF recurrence group than in the non-recurrence group (P < 0.001, respectively). Mean percent changes from LA EF(2) to LA EF(3) were -0.4 ± 3.4 in the AF recurrence group and 5.2 ± 4.9 in the non-recurrence group (P = 0.041). The change in mean EF from LA EF(1) to LA EF(3) in the non-recurrence group was significantly greater than in the recurrence group (P = 0.001). Cox regression analysis showed that predictors of AF recurrence were LA EF(2), LA EF(3) and accompanied obstructive sleep apnea (OSA) (P < 0.001, respectively). Decreased functional LA reservoir (LA EF after RVP) and OSA are significantly related to recurrence of AF following CA in patients with paroxysmal AF.

Introduction: Complex fractionated atrial electrograms (CFAEs) are a substrate modification target in patients with atrial fibrillation (AF). However, whether CFAEs can be also arrhythmogenic grounds of atrial tachycardia (AT) presenting after AF ablation remains to be determined. We investigated the relationship between CFAEs and the critical site of AT after CFAE-guided AF ablation., Methods and Results: Seventy-two patients showing AT after pulmonary vein isolation and further CFAE-guided ablation were included. The termination sites of the 95 distinct ATs were annotated on color-coded CFAE cycle maps. Of the 95 ATs, 61 (64.2%) had a termination site at the border zone of CFAE or in a highly dense CFAE area. The cycle length (CL) of the ATs terminated in the CFAE area was significantly shorter than the CL of those terminated in the non-CFAE area. The cut-off CL for ATs terminated at the CFAE area was 270 milliseconds, with sensitivity/specificity of 70%/75%. In 67.2% of the ATs terminating at the CFAE-related area, the major termination sites were the anterior wall near the LA appendage, septum and roof, whereas the peri-mitral isthmus was the most common termination site of ATs in the non-CFAE area., Conclusions: The areas showing CFAE and their border zones were frequently associated with termination of ATs presenting after AF ablation. The mean CL of ATs originating near CFAEs was significantly shorter than that of those terminated in non-CFAE areas. The targeted CFAE areas also provided the arrhythmogenic milieu for AT developing after AF ablation., (© 2013 Wiley Periodicals, Inc.)

The aim of this study was to assess the clinical and echocardiographic predictors for the recurrence of persistent atrial fibrillation (AF) after ablation during a long-term period.A total of 130 patients with persistent AF who had undergone radiofrequency catheter ablation (RFCA) were enrolled. We analyzed the relation between clinical parameters, echocardiographic parameters, and AF recurrences at 6 months, 1 year, and 2 years after ablation.During the 2-year follow-up, AF recurred in 61 patients (46.6%). In the 6 month follow-up, AF recurrence was associated only with total ablation time only. However, during the 1-year and 2-year follow-up periods, the presence of hypertension, impaired left atrial (LA) emptying fraction (eF) (≤ 20%), decreased LA appendage (LAA) emptying velocity (≤ 20 cm/sec), and LAAeF (≤ 20%) were correlated with AF recurrence (odds ratio [OR] = 1.87, 2.45, 1.93, and 2.15 respectively, P = 0.016, 0.004, 0.029, and 0.004 respectively). Among these factors, impaired LAeF was the only independent predictor of AF recurrence in multivariate analysis (OR = 2.81, P = 0.012).In patients with persistent AF who had undergone RFCA, the best predictor of AF recurrence after ablation varied according to the follow-up period. Diminished LA function was the only predictor of recurrence in the 2-year follow-up. Pre-procedural assessment of LA function might be helpful in selecting those patients who would benefit from RFCA.

Metastatic spine disease (MSD) is a complex disease entity requiring multi-discipline and multi-modality approach to obtain the most reasonable clinical outcomes. As one of these trials, radiofrequency ablation (RFA) has been tried. Here, we describe four cases of metastatic spine lesions (2 hepatomas, 1 lung cancer, 1 breast cancer) that were treated with intraoperative RFA to control the lesion and to limit tumor contamination. During 3-month follow-up, most patients experienced effective pain relief and improvement of their functional status. However, their final results were diverse. There were no complications related to this procedure. In two cases, the treated lesions were re-evaluated radiologically using PET-CT and diffusion-weighted MRI. Up to the time of this report, the patients are well without progressive deterioration of the treated lesion. With review of the related literatures, we discuss the efficacy and safety of this therapeutic approach as one of options for the treatment of MSD with neurologic manifestations.

Background: The role of right atrial (RA) ablation guided by complex fractionated atrial electrograms (CFAE) in atrial fibrillation (AF) has been debated. This study evaluated the spatial distribution of RA CFAE, the critical sites, and the predictors of successful termination of longstanding persistent AF during RA ablation., Methods: A total of 97 patients with persistent AF who received automated detection of CFAE mapping and ablation at the RA for sustained AF after pulmonary vein isolation and left atrial (LA) CFAE-guided ablation were analyzed. The AF termination patterns and CFAE areas were analyzed., Results: Forty-eight (49%) patients successfully converted to atrial tachycardia (AT) or sinus rhythm (SR) during CFAE-guided ablation at the RA. Of these, 7 (15%) patients converted directly to SR, and 41 (85%) converted via AT. The crista terminalis (CT) was the most common site for AT conversion during RA CFAE ablation, followed by the RA appendage and RA septum. Patients with larger RA volumes (> 145 mm3) had lower rates of SR or AT conversion during RA CFAE ablation. Patients with AF termination during RA CFAE ablation had less late recurrence than those without AF termination (P = 0.003)., Conclusion: A half of patients with persistent AF refractory to LA ablation successfully converted to AT or SR during automated CFAE-guided ablation at the RA. The most common critical sites for AF termination were the CT and RA appendage and septum. Patients with AF termination during procedure whether LA CFAE only or after RA CFAE ablation had better outcome with less late recurrence of atrial tachyarrhythmia compared to those without AF termination., (© 2013 Wiley Periodicals, Inc.)