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Background: Dexmedetomidine and propofol are common sedatives in intensive care units and for interventional procedures. Both may compromise sinus node function and atrioventricular conduction. The objective of this prospective, randomized study is to compare the effect of dexmedetomidine with propofol on sinus node function and atrioventricular conduction., Methods: In a tertiary care center in Switzerland we included from September 2019 to October 2020 160 patients (65 ± 11 years old; 32% female) undergoing first ablation for atrial fibrillation by cryoballoon ablation or by radiofrequency ablation. Patients were randomly assigned to deep sedation with dexmedetomidine (DEX group) versus propofol (PRO group). A standard electrophysiological study was performed after pulmonary vein isolation with the patients still deeply sedated and hemodynamically stable., Results: Eighty patients each were randomized to the DEX and PRO group. DEX group patients had higher baseline sinus cycle length (1022 vs. 1138 ms; p = 0.003) and longer sinus node recovery time (SNRT400; 1597 vs. 1412 ms; p = 0.042). However, both corrected SNRT and normalized SNRT did not differ. DEX group patients had longer PR interval (207 vs. 186 ms; p = 0.002) and AH interval (111 vs. 95 ms, p = 0.008), longer Wenckebach cycle length of the atrioventricular node (512 vs. 456 ms; p = 0.005), and longer atrioventricular node effective refractory period (390 vs. 344 ms; p = 0.009). QRS width and HV interval were not different. An arrhythmia, mainly atrial fibrillation, was induced in 33 patients during the electrophysiological study, without differences among groups (20% vs. 15%, p = 0.533)., Conclusions: Dexmedetomidine has a more pronounced slowing effect on sinus rate and suprahissian AV conduction than propofol, but not on infrahissian AV conduction and ventricular repolarization. These differences need to be taken into account when using these sedatives., Trial Registration: ClinicalTrials.gov number NCT03844841, 19/02/2019., (© 2024. The Author(s).)

Background: Single-shot devices are increasingly used for pulmonary vein isolation (PVI) in atrial fibrillation (AF). The Arctic Front cryoballoon is the most frequently used single-shot technology. A recently developed novel pulsed field ablation (PFA) device (FARAPULSE) has been introduced with the aim to improve procedural safety and efficacy., Objective: This study will compare the novel FARAPULSE PFA device and the Arctic Front cryoballoon for first PVI in patients with symptomatic paroxysmal AF., Methods: SINGLE SHOT CHAMPION is a multicenter, randomized controlled trial with blinded endpoint adjudication by an independent clinical events committee. Overall, 210 patients with paroxysmal AF undergoing their PVI are randomized 1:1 between PFA and cryoballoon ablation. Continuous rhythm monitoring with an implantable cardiac monitor is performed in all patients., Results: The primary endpoint is time to first recurrence of any atrial tachyarrhythmia (AF and/or organized atrial tachyarrhythmia) lasting ≥120 seconds and identified by the implantable cardiac monitor within 91 and 365 days postablation. The composite procedural safety endpoint includes cardiac tamponade requiring drainage, persistent phrenic nerve palsy, vascular complications requiring intervention, stroke/transient ischemic attack, atrioesophageal fistula, and death occurring during or up to 30 days after the procedure. Key secondary endpoints include (1) increase in high-sensitivity troponin on day 1 postablation, (2) analysis of postablation 3-dimensional electroanatomic mapping (first 25 patients per study group), (3) AF burden, and (4) quality-of-life changes., Conclusion: SINGLE SHOT CHAMPION will evaluate the efficacy and safety of PVI using the novel FARAPULSE PFA for patients with symptomatic paroxysmal AF., (© 2024 Heart Rhythm Society. Published by Elsevier Inc.)

Background: Pulsed-field ablation (PFA) is a novel nonthermal ablation technology. Its potential value for repeat procedures after unsuccessful thermal ablation for atrial fibrillation has not been assessed., Objective: The purpose of this study was to summarize our initial experience with patients undergoing repeat procedures using PFA., Methods: Consecutive patients with arrhythmia recurrences after a prior thermal ablation undergoing a repeat procedure using a multipolar PFA catheter from May 2021 and December 2022 were included. After 3-dimensional electroanatomic mapping, reconnected pulmonary veins (PVs) were reisolated and veins with only ostial isolation wither ablated to widen antral PV isolation. Posterior wall ablation was performed if all PVs were durably isolated or in case of low-voltage areas on the posterior wall at the discretion of the operator. Patients underwent follow-up with 7-day Holter electrocardiography after 3, 6, and 12 months., Results: A total of 186 patients undergoing a repeat procedure using PFA were included. The median number of previous ablations was 1 (range 1-6). The prior ablation modality was radiofrequency in 129 patients (69.4%), cryoballoon in 51 (27.4%), and epicardial ablation in 6 (3.2%). At the beginning of the procedure, 258 of 744 PVs (35%) showed reconnections. Additional antral ablations were applied in 236 of 486 still isolated veins (49%). Posterior wall ablation was added in 125 patients (67%). Major complications occurred in 1 patient (transient ischemic attack 0.5%). Freedom from arrhythmia recurrence in Kaplan-Meier-analysis was 78% after 6 months and 54% after 12 months., Conclusion: PFA is a versatile and safe option for repeat procedures after failed prior thermal ablation., (© 2024 Heart Rhythm Society. Published by Elsevier Inc.)

Aims: Pulmonary vein isolation (PVI) is increasingly performed in patients with atrial fibrillation (AF). Both AF phenotype and left atrial (LA) volume have been shown to influence ablation outcome. The inter-relationship of the two is incompletely understood. We aimed to investigate the impact of AF phenotype vs. LA volume on outcome after PVI., Methods and Results: In a retrospective analysis of a prospective registry of patients undergoing a first PVI, the association of AF phenotype and LA volume index (LAVI) was assessed as well as their impact on AF recurrence during follow-up. Overall, 476 patients were enrolled (median age 63 years, 29% females, 65.8% paroxysmal AF). Obesity, hypertension, chronic kidney disease, and heart failure were all significantly more frequent in persistent AF. After 1 year, single-procedure, freedom from arrhythmia recurrence was 61.5%. Patients with paroxysmal AF had better outcomes compared with patients with persistent AF (65.6 vs. 52.7%, P = 0.003), as had patients with no/mild vs. moderate/severe LA dilation (LAVI <42 mL/m2 67.1% vs. LAVI ≥42 mL/m2 53%, P < 0.001). The combination of both parameters refined prediction of 1-year recurrence (P < 0.001). After adjustment for additional clinical risk factors in multivariable Cox proportional hazard analysis, both AF phenotype and LAVI ≥42 mL/m2 contributed significantly towards the prediction of 1-year recurrence., Conclusion: Atrial fibrillation phenotype and LA volume are independent predictors of outcome after PVI. Persistent AF with no/mild LA dilation has a similar risk of recurrence as paroxysmal AF with a moderate/severe LA dilation and should be given similar priority for ablation., Competing Interests: Conflict of interest: T.R. has received research grants from the Swiss National Science Foundation, the Swiss Heart Foundation, the Sitem Insel Support Fund, Biotronik, Boston Scientific, and Medtronic, all for work outside the submitted study. He has received speaker/consulting honoraria or travel support from Abbott/SJM, Biosense Webster, Biotronik, Boston Scientific, and Medtronic. He has received support for his institution’s fellowship programme from Abbott/SJM, Biosense Webster, Biotronik, Boston Scientific, and Medtronic. L.R. has received research grants from Medtronic, the Swiss National Foundation, the Swiss Heart Foundation, the Immanuel and Ilse Straub Foundation, and the Sitem Insel Support Fund, all for work outside the submitted study. He has received speaker/consulting honoraria from Abbott and Medtronic. A.H.: travel fees/educational grants from Medtronic, Biotronik, Abbott, and Philips/Spectranetics without impact on his personal remuneration. He serves as a proctor for Medtronic. He has received research grants from the Swiss National Science Foundation, the Swiss Innovation Agency Innosuisse, the Swiss Heart Foundation, the University of Bern, the University Hospital Bern, the Velux Foundation, the Hasler Foundation, the Swiss Heart Rhythm Foundation, and the Novartis Research Foundation. He is the co-founder and CEO of Act-Inno AG. All other authors have no relationships relevant to the contents of this paper to disclose., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Screening for atrial fibrillation (AF) may reveal incidental arrhythmias of relevance. The aim of this study was to describe incidental arrhythmias detected during screening for AF in the STAR-FIB (Predicting SilenT AtRial FIBrillation in Patients at High Thrombembolic Risk) cohort study., Methods and Results: In the STAR-FIB cohort study, we screened hospitalized patients for AF with 3 repeat 7-day Holter ECGs. We analyzed all Holter ECGs for the presence of the following incidental arrhythmias: (1) sinus node dysfunction, defined as sinus pause of ≥3 seconds' duration; (2) second-degree (including Wenckebach) or higher-degree atrioventricular block (AVB); (3) sustained supraventricular tachycardia of ≥30 seconds' duration; and (4) sustained ventricular tachycardia of ≥30 seconds' duration. We furthermore report treatment decisions because of incidental arrhythmias. A total of 2077 Holter ECGs were performed in 794 patients (mean age, 74.7 years; 49% women), resulting in a mean cumulative duration of analyzable ECG signal of 414±136 hours/patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were sinus node dysfunction in 14 patients (1.8%), AVB in 41 (5.2%), supraventricular tachycardia in 42 (5.3%), and ventricular tachycardia in 2 (0.3%). Second-degree AVB was found in 23 patients (2.9%), 2:1 AVB in 10 (1.3%), and complete AVB in 8 (1%). Subsequently, 8 patients underwent pacemaker implantation, 1 for sinus node dysfunction (post-AF conversion pause of 9 seconds) and 7 for advanced AVB. One patient had an implantable cardioverter-defibrillator implanted for syncopal ventricular tachycardia., Conclusions: Incidental arrhythmias were frequently detected during screening for AF in the STAR-FIB study and resulted in device therapy in 1.1% of our cohort patients.

Aims: The aim of the study was to compare the 1-year efficacy and safety of a novel cryoballoon (NCB) ablation system (POLARx; Boston Scientific) for pulmonary vein isolation (PVI) compared with the standard cryoballoon (SCB) system (Arctic Front, Medtronic)., Methods and Results: Consecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB at two centres were included. We report 1-year efficacy after 12 months, short-term safety and hospitalizations within the blanking period, and predictors for AF recurrence. In case of repeat procedures, pulmonary vein (PV) reconnection patterns were characterized. Eighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 39 ± 13 mL/m2, paroxysmal AF in 64%) were studied. After a single procedure and a follow-up of 12 months, 68% in the NCB group and 70% in the SCB group showed no recurrence of AF/atrial tachycardias (P = 0.422). One patient in the NCB group suffered a periprocedural stroke with full recovery. There were no differences regarding hospitalizations during follow-up between the groups. PV reconnection observed during 12 repeat procedures (4 NCB, 8 SCB) pattern was comparable between the groups with more reconnections in the right-sided compared with the left-sided PVs., Conclusion: In this multicentre study comparing two currently available cryoballoon ablation systems for PVI, no differences were observed in the efficacy and safety during a follow-up of 12 months., Competing Interests: Conflict of interest: T.R. has received speaker/consulting honoraria or travel support from Abbott/SJM, Astra Zeneca, Brahms, Bayer, Biosense-Webster, Biotronik, Boston-Scientific, Daiichi Sankyo, Medtronic, Pfizer-BMS, and Roche, all for work outside the submitted study. He has received research grants from the Goldschmidt-Jacobson Foundation, the Swiss National Science Foundation, the Swiss Heart Foundation, the European Union (Eurostars 9799–ALVALE), the Professor Max Cloëtta Foundation, the Cardiovascular Research Foundation Basel, the University of Basel, and the University Hospital Basel. He has received support for his institution’s fellowship program from Abbott/SJM, Biosense-Webster, Biotronik, Boston-Scientific, and Medtronic for work outside the submitted study. S.H.B. has received research support from Biosense-Webster and travel grants from Biosense Webster and Boston-Scientific all for work outside the submitted study. L.R. has received speaker/consulting honoraria from Abbott/SJM and Medtronic. M.K. reports grants from the Swiss National Science Foundation, Swiss Heart Foundation, Bayer, Pfizer BMS, Boston Scientific, personal fees from Bayer, Böhringer Ingelheim, Pfizer BMS, Daiichi Sankyo, Medtronic, Biotronik, Boston Scientific, Johnson & Johnson all outside the submitted work. C.S. reports grants from the European Union’s FP7 program, Biosense-Webster and lecture and consulting fees from Abbott, Medtronic, Biosense-Webster, Boston Scientific, Microport, and Biotronik. S.K. reports grant from the Stiftung Kardiovaskuläre Forschung. The rest of the authors report no conflicts of interest. No commercial entities participated in this study., (© 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 The association of epicardial adipose tissue (EAT) and its metabolic activity with atrial fibrillation (AF) is an area of active investigation. Left atrial (LA) enhancing EAT (e-EAT) at cardiac CT may be a noninvasive surrogate marker for the metabolic activity of EAT. Purpose To determine the relationship between LA e-EAT and recurrence after AF ablation. Materials and Methods In a secondary analysis of a prospective registry of consecutive patients (from July 2018 to December 2019) undergoing first AF ablation, total and LA EAT were segmented on preprocedural noncontrast- and contrast-enhanced cardiac CT scans. LA e-EAT volume fraction was defined as the LA EAT volume difference between the noncontrast- and contrast-enhanced scan divided by the total LA EAT volume on the noncontrast-enhanced scan (threshold values, -15 HU to -195 HU). Continuous variables were compared between groups by using the Mann-Whitney U test. Cox proportional hazard models were used to calculate hazard ratios of predictors of 1-year AF recurrence. Results A total of 212 patients (mean age, 64 years; 159 men) who underwent a first AF ablation were included (paroxysmal AF, 64%; persistent AF, 36%). The LA EAT volume was higher in patients with persistent versus paroxysmal AF (50 cm 3 [IQR, 37-72] vs 37 [IQR, 27-49]; P < .001), but no difference was found for LA e-EAT ( P = .09). After 1 year of follow-up, AF recurrence rate was 77 of 212 (36%). LA e-EAT above the mean (>33%) was associated with a higher risk of AF recurrence (hazard ratio [HR], 2.1; 95% CI: 1.3, 3.3; P < .01). In a multivariable Cox regression analysis, LA e-EAT retained its predictive value when corrected for sex, age, AF phenotype, LA volume index, and LA EAT volume (HR, 1.9; 95% CI: 1.1, 3.1; P = .02). Conclusion Left atrial enhancing epicardial adipose tissue was independently associated with recurrence after atrial fibrillation ablation. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Stojanovska in this issue.

Aims: To validate the performance of a multipolar pulsed-field ablation (PFA) catheter compared to a standard pentaspline 3D-mapping catheter for endpoint assessment of pulmonary vein isolation (PVI). PFA for PVI using single-shot devices combines the benefits of high procedural efficacy and safety. A newly available multipolar PFA catheter allows real-time recording of pulmonary vein (PV) signals during PVI., Methods and Results: Patients undergoing first PVI using PFA with the standard ablation protocol (eight applications per PV) were studied. Entrance and exit block (10 V/2 ms) were assessed using the PFA catheter. Subsequently, a high-density 3D electroanatomical bipolar voltage map (3D-EAM) was constructed using a standard pentaspline 3D-mapping catheter. Additional PFA applications were delivered only after confirmation of residual PV connection by 3D-EAM. In 56 patients, 213 PVs were targeted for ablation. Acute PVI was achieved in 100% of PVs: in 199/213 (93%) PVs with the standard ablation protocol alone and in the remaining 14 PVs after additional PFA applications. The accuracy of PV assessment with the PFA catheter after the standard ablation protocol was 91% (194/213 veins). In 5/213 (2.3%) PVs, the PFA catheter incorrectly indicated PV-isolation. In 14/213 (6.6%), the PFA catheter incorrectly indicated residual PV-conduction due to high-output pace-capture. Lowering the output to 5 V/1 ms reduced this observation to 0.9% (2/213) and increased the overall accuracy to 97% (206/213)., Conclusion: A novel multipolar PFA catheter allows reliable endpoint assessment for PVI. Due to its design, far-field sensing and high-output pace-capture can occur. Lowering the pacing output increases the accuracy from 91 to 97%., Competing Interests: Conflict of interest: A.H.: Research grants from the Swiss National Science Foundation, the Swiss Heart Foundation, the University of Bern, the University Hospital Bern, the Velux Foundation, the Hasler Foundation, the Swiss Heart Rhythm Foundation, and the Novartis Research Foundation. He is a Co-founder and CEO of Act-Inno, a cardiovascular device testing company. He has received travel fees/educational grants from Medtronic, Philips/Spectranetics, and Cairdac without impact on his personal remuneration. L.R.: speaker honoraria from Abbott/SJM and consulting honoraria from Medtronic. T.R.: Research grants from the Goldschmidt-Jacobson Foundation, the Swiss National Science Foundation, the Swiss Heart Foundation, the [European Union Eurostars (9799)—ALVALE], and the Professor Max Cloëtta Foundation, all for work outside the submitted study. Speaker/consulting honoraria or travel support from Abbott/SJM, Astra Zeneca, Brahms, Bayer, Biosense-Webster, Biotronik, Boston-Scientific, Daiichi Sankyo, Medtronic, Pfizer-BMS, and Roche, all for work outside the submitted study. Support for his institution’s fellowship program from Abbott/SJM, Biosense-Webster, Biotronik, Boston-Scientific, and Medtronic for work outside the submitted study. F.N.: Medtronic, Abbott: Travel fees, speaker fees, educational grant; Boston-Scientific, Philips Spectranetics: Travel fees, educational grant; Biotronik: Institutional grant all for work outside the submitted study. A.M. owns stock from Boston-Scientific. J.S.: The spouse of Dr Seiler is an employee and stock owner of Boston-Scientific. All other authors report no conflicts of interest related to this paper., (© The Author(s) 2022. Published by Oxford University Press on behalf of European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Congenital long-QT syndrome (LQTS) is a major cause of sudden cardiac death (SCD) in young individuals, calling for sophisticated risk assessment. Risk stratification, however, is challenging as the individual arrhythmic risk varies pronouncedly, even in individuals carrying the same variant., Materials and Methods: In this study, we aimed to assess the association of different electrical parameters with the genotype and the symptoms in patients with LQTS. In addition to the heart-rate corrected QT interval (QTc), markers for regional electrical heterogeneity, such as QT dispersion (QT max -QT min in all ECG leads) and delta T peak/end (T peak/end V5 - T peak/end V2), were assessed in the 12-lead ECG at rest and during exercise testing., Results: QTc at rest was significantly longer in symptomatic than asymptomatic patients with LQT2 (493.4 ms ± 46.5 ms vs. 419.5 ms ± 28.6 ms, p = 0.004), but surprisingly not associated with symptoms in LQT1. In contrast, post-exercise QTc (minute 4 of recovery) was significantly longer in symptomatic than asymptomatic patients with LQT1 (486.5 ms ± 7.0 ms vs. 463.3 ms ± 16.3 ms, p = 0.04), while no such difference was observed in patients with LQT2. Enhanced delta T peak/end and QT dispersion were only associated with symptoms in LQT1 (delta T peak/end 19.0 ms ± 18.1 ms vs. -4.0 ms ± 4.4 ms, p = 0.02; QT-dispersion: 54.3 ms ± 10.2 ms vs. 31.4 ms ± 10.4 ms, p = 0.01), but not in LQT2. Delta T peak/end was particularly discriminative after exercise, where all symptomatic patients with LQT1 had positive and all asymptomatic LQT1 patients had negative values (11.8 ± 7.9 ms vs. -7.5 ± 1.7 ms, p = 0.003)., Conclusion: Different electrical parameters can distinguish between symptomatic and asymptomatic patients in different genetic forms of LQTS. While the classical "QTc at rest" was only associated with symptoms in LQT2, post-exercise QTc helped distinguish between symptomatic and asymptomatic patients with LQT1. Enhanced regional electrical heterogeneity was only associated with symptoms in LQT1, but not in LQT2. Our findings indicate that genotype-specific risk stratification approaches based on electrical parameters could help to optimize risk assessment in LQTS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Rieder, Kreifels, Stuplich, Ziupa, Servatius, Nicolai, Castiglione, Zweier, Asatryan and Odening.)

Background: Transcatheter aortic valve implantation (TAVI) is associated with new onset brady- and tachyarrhythmias which may impact clinical outcome., Aims: To investigate the true incidence of new onset arrhythmias within 12 months after TAVI using an implantable cardiac monitor (ICM)., Methods: One hundred patients undergoing TAVI received an ICM within 3 months before or up to 5 days after TAVI. Patients were followed-up for 12 months after discharge from TAVI for the occurrence of atrial fibrillation (AF), bradycardia (≤30 bpm), advanced atrioventricular (AV) block, sustained ventricular and supraventricular tachycardia., Results: A previously undiagnosed arrhythmia was observed in 31 patients (31%) and comprised AF in 19 patients (19%), advanced AV block in 3 patients (3%), and sustained supraventricular and ventricular tachycardia in 10 (10%) and 2 patients (2%), respectively. Three patients had a clinical diagnosis of sick-sinus-syndrome. A permanent pacemaker (PPM) was implanted in six patients (6%). The prevalence of pre-existing AF was 28%, and 47% of the patients had AF at the end of the study period. AF burden was significantly higher in patients with pre-existing [26.7% (IQR 0.3%; 100%)] compared to patients with new-onset AF [0.0% (IQR 0.0%; 0.06%); p = 0.001]. Three patients died after TAVI without evidence of an arrhythmic cause according to the available ICM recordings., Conclusions: Rhythm monitoring for 12 months after TAVI revealed new arrhythmias, mainly AF, in almost one third of patients. Atrial fibrillation burden was higher in patients with prevalent compared to incident AF. Selected patients may benefit from short-term remote monitoring., Trial Registration: https://clinicaltrials.gov/: NCT02559011., Competing Interests: The spouse of JS is an employee of Boston Scientific. HT reports educational grants from Biosense Webster and travel grants from Abbott. FN reports travel fees from Medtronic, Abbott, Boston Scientific and Philips Spectranetics, speaker fees from Medtronic and Abbott, educational grants from Medtronic, Abbott, Boston Scientific, Philips Spectranetics and Actinno and institutional grants from Biotronik. AH received travel/educational grants from Medtronic and Philips/Spectranetics. He is consultant/advisor for DiNAQOR and Biotronik and Co-founder/head of Act-Inno. SS reports research grants to the institution from Edwards Lifesciences, Medtronic, Boston Scientific and Abbott, as well as personal fees from Boston Scientific, Teleflex and BTG. TP reports research grants to the institution from Biotronik, Boston Scientific and Edwards Lifesciences; speaker fees from Biotronik and Boston Scientific; Clinical event committee for study sponsored by HighLifeSAS; travel reimbursement from Medira; proctoring for Medtronic. SW reports research and educational grants to the institution from Abbott, Amgen, Astra Zeneca, BMS, Bayer, Biotronik, Boston Scientific, Cardinal Health, CardioValve, CSL Behring, Daiichi Sankyo, Edwards Lifesciences, Guerbet, InfraRedx, Johnson & Johnson, Medicure, Medtronic, Novartis, Polares, OrPha Suisse, Pfizer, Regeneron, Sanofi-Aventis, Sinomed, Terumo, V-Wave. He serves as unpaid advisory board member and/or unpaid member of the steering/executive group of trials funded by Abbott, Abiomed, Amgen, Astra Zeneca, Bayer, BMS, Boston Scientific, Biotronik, Cardiovalve, Edwards Lifesciences, MedAlliance, Medtronic, Novartis, Polares, Sinomed, Terumo, V-Wave and Xeltis, but has not received personal payments by pharmaceutical companies or device manufacturers. He is also member of the steering/executive committee group of several investigator-initiated trials that receive funding by industry without impact on his personal remuneration. TR reported research grants from the Goldschmidt-Jacobson Foundation, the Swiss National Science Foundation, the Swiss Heart Foundation and the sitem-insel Support Funds, all for work outside the submitted study; advisory board membership, speaker and travel support from Abbott/SJM, Astra Zeneca, Brahms, Bayer, Biosense-Webster, Biotronik, Boston-Scientific, Daiichi Sankyo, Medtronic, Pfizer-BMS and Roche, all for work outside the submitted study and without impact on his personal remuneration; as well as support for his institution's fellowship program from Abbott/SJM, Biosense-Webster, Biotronik, Boston-Scientific and Medtronic for work outside the submitted study and without impact on his personal remuneration. FP reports travel expenses from Abbott Vascular, Edwards Lifesciences, and Polares Medical. LR received speaker honoraria from Abbott/SJM and consulting honoraria from Medtronic. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Nozica, Siontis, Elchinova, Goulouti, Asami, Bartkowiak, Baldinger, Servatius, Seiler, Tanner, Noti, Haeberlin, Branca, Lanz, Stortecky, Pilgrim, Windecker, Reichlin, Praz and Roten.)

Background: Hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD) and athletes’ heart share an increased prevalence of atrial fibrillation. Atrial cardiomyopathy in these patients may have different characteristics and help to distinguish these conditions. Methods: In this single-center study, we prospectively collected and analyzed electrocardiographic (12-lead ECG, signal-averaged ECG (SAECG), 24 h Holter ECG) and echocardiographic data in patients with HCM and HHD and in endurance athletes. Patients with atrial fibrillation were excluded. Results: We compared data of 27 patients with HCM (70% males, mean age 50 ± 14 years), 324 patients with HHD (52% males, mean age 75 ± 5.5 years), and 215 endurance athletes (72% males, mean age 42 ± 7.5 years). HCM patients had significantly longer filtered P-wave duration (153 ± 26 ms) and PR interval (191 ± 48 ms) compared to HHD patients (144 ± 16 ms, p = 0.012 and 178 ± 31, p = 0.034, respectively) and athletes (134 ± 14 ms, p = 0.001 and 165 ± 26 ms, both p < 0.001, respectively). HCM patients had a mean of 4.9 ± 16 premature atrial complexes per hour. Premature atrial complexes per hour were significantly more frequent in HHD patients (27 ± 86, p < 0.001), but not in athletes (2.7 ± 23, p = 0.639). Left atrial volume index (LAVI) was 43 ± 14 mL/m2 in HCM patients and significantly larger than age- and sex-corrected LAVI in HHD patients 30 ± 10 mL/m2; p < 0.001) and athletes (31 ± 9.5 mL/m2; p < 0.001). A borderline interventricular septum thickness ≥13 mm and ≤15 mm was found in 114 (35%) HHD patients, 12 (6%) athletes and 3 (11%) HCM patients. Conclusions: Structural and electrical atrial remodeling is more advanced in HCM patients compared to HHD patients and athletes.

Background: The prevalence of atrial fibrillation (AF) is high in older patients. The present study aimed to estimate the age and sex specific prevalence of clinical and screen-detected atrial fibrillation (AF) in hospitalized patients., Methods: The STAR-FIB cohort study was a prospective cohort study recruiting participants from a large source population of hospitalized patients aged 65-84 years. The estimated size of the source population was 26,035 (95% CI 25,918-26,152), and 795 consenting patients without clinical AF were included in the cohort study after stratification by sex and age (49.2% females; mean age 74.7 years). Patients in the cohort study underwent three seven-day Holter ECGs in intervals of two months to screen for AF., Results: In the source population, the estimated prevalence of clinical AF was 22.2% (95% CI 18.4-26.1), 23.8% for males (95% CI 20.9-26.6) and 19.8% for females (95% CI 17.3-22.4; p for difference between sexes, 0.004). There was a linear trend for an increase in the prevalence of clinical AF with increasing age, overall and in both sexes. In the cohort study, AF was newly diagnosed in 38 patients, for an estimated prevalence of screen-detected AF of 4.9% overall (95% CI 3.3-6.6), 5.5% in males (95% CI 3.2-7.8) and 4.0% in females (95% CI 2.0-6.0; p for difference between sexes, 0.041). The estimated prevalence of screen-detected AF in the source population was 3.8% overall, 4.2% in males and 3.2% in females., Conclusion: In a large hospital-based patient population aged 65-84 years, the prevalence of clinical AF and of screen-detected AF was 22.2% and 3.8%, respectively, and significantly higher in males than females.

Aims of the Study: Anticoagulation of patients with screen-detected atrial fibrillation may prevent ischaemic strokes. The STAR-FIB study programme aims to determine the age- and sex-specific prevalence of silent atrial fibrillation and to develop a clinical prediction model to identify patients at risk of undiagnosed atrial fibrillation in a hospitalised patient population., Methods: The STAR-FIB study programme includes a prospective cohort study and a case-control study of hospitalised patients aged 65&ndash;84 years, evenly distributed for both age and sex. We recruited 795 patients without atrial fibrillation for the cohort study (49.2% females; median age 74.8 years). All patients had three serial 7-day Holter ECGs to screen for silent atrial fibrillation. The primary endpoint will be any episode of atrial fibrillation or atrial flutter of &ge;30 seconds duration. The age- and sex-specific prevalence of newly diagnosed atrial fibrillation will be estimated. For the case-control study, 120 patients with paroxysmal atrial fibrillation were recruited as cases (41.7% females; median age 74.6 years); controls will be randomly selected from the cohort study in a 2:1 ratio. All participants in the cohort study and all cases were prospectively evaluated including clinical, laboratory, echocardiographic and electrical parameters. A clinical prediction model for undiagnosed atrial fibrillation will be derived in the case-control study and externally validated in the cohort study., Conclusions: The STAR-FIB study programme will estimate the age- and sex-specific prevalence of silent atrial fibrillation in a hospitalised patient population, and develop and validate a clinical prediction model to identify patients at risk of silent atrial fibrillation.

Sex-related differences in prevalence, clinical presentation, and outcome of cardiac channelopathies are increasingly recognized, despite their autosomal transmission and hence equal genetic predisposition among sexes. In congenital long-QT syndrome, adult women carry a greater risk for Torsades de pointes and sudden cardiac death than do men. In contrast, Brugada syndrome is observed predominantly in adult men, with a considerably higher risk of arrhythmic sudden cardiac death in adult men than in women. In both conditions, the risk for arrhythmias varies with age. Sex-associated differences appear less evident in other cardiac channelopathies, likely a reflection of their rare(r) occurrence and our limited knowledge. In several cardiac channelopathies, sex-specific predictors of outcome have been identified. Together with genetic and environmental factors, sex hormones contribute to the sex-related disparities in cardiac channelopathies through modulation of the expression and function of cardiac ion channels. Despite these insights, essential knowledge gaps exist in the mechanistic understanding of these differences, warranting further investigation. Precise application of the available knowledge may improve the individualized care of patients with cardiac channelopathies. Promoting the reporting of sex-related phenotype and outcome parameters in clinical and experimental studies and advancing research on cardiac channelopathy animal models should translate into improved patient outcomes. This review provides a critical digest of the current evidence for sex-related differences in cardiac channelopathies and emphasizes their clinical implications and remaining gaps requiring further research.

Aims: Leadless cardiac pacemaker (PM) implantation differs from conventional PM implantation. While the procedure has been considered safe, recent real-world data raised concerns about the learning curve of new operators and their implantation quality. The goal of this study was to investigate the influence of the first operator's experience on leadless PM implantation quality and procedural efficiency., Methods and Results: We performed a bicentric analysis of all Micra TPS™ implantations in two large tertiary referral hospitals. We assessed both leadless PM implantation quality based on the absence of complications (requiring intervention or prolonged hospitalization), good electrical performance (pacing threshold ≤ 1.5 V/0.24 ms, R-wave amplitude > 5 mV), and acceptable fluoroscopy duration (<10 min) as well as procedural efficiency in relation to the operator's experience. Univariate and multivariate logistic regression analyses were performed to identify predictors for implantation quality and procedural efficiency. Leadless PM implantation was successful in 106/111 cases (95.5%). Three patients (2.7%) experienced acute complications (one cardiac tamponade, one femoral bleeding, one posture-related PM exit block). Multivariate analysis showed that implantation quality of more experienced first operators was higher [odds ratio 1.09 (95% confidence interval 1.00-1.19), P = 0.05]. Procedural efficiency increased with operator experience as evidenced by an inverse correlation of procedure time, time to the first deployment, fluoroscopy time, and the number of procedures performed (all P < 0.05)., Conclusion: The operator's learning curve is a critical factor for leadless PM implantation quality and procedural efficiency., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Objectives: Our goal was to analyse the implantation and outcome of thoracoscopic epicardial leads after a failed endovascular approach or follow-up (FU) complications after endovascular implantation., Methods: We reviewed the records of patients with failed endovascular left ventricular (LV) lead placement or complications during FU, who were subsequently referred to cardiac surgeons for treatment with thoracoscopic LV lead implantation. We analysed the reasons for endovascular failure; the indications for the surgical procedures; and the clinical, echocardiographic and device FU results., Results: Between 2010 and 2013, a total of 23 patients were included. Among them, 17 of the patients had no previous cardiothoracic surgery, 13 (76%) had successful video-assisted thoracoscopy (VAT) LV lead implantation, 3 (18%) had a conversion to thoracotomy and 1 (6%) failed. Of the 6 patients with prior cardiothoracic surgery, 2 (33%) had VAT only, 3 (50%) had primary thoracotomies and 1 (17%) had a conversion. Two major complications occurred. The reasons for LV endovascular lead failure were subclavian vein occlusion (n = 2), implant failure (n = 13) and complications during the FU period (n = 8). FU information was available for 20 patients: 17 (85%) had improved symptoms. The median FU period was 33 months. A total of 78% of patients were in New York Heart Association (NYHA) functional class III-IV before the operation; 30% were in NYHA functional class III-IV at the last FU examination. The left ventricular ejection fraction increased from 25% before surgery to 31% at the last FU examination. Overall, sensing and pacing threshold values remained stable over time. In 1 patient, lead revision was necessary due to an increase in the pacing threshold., Conclusions: VAT implantation of LV leads had an excellent response rate with an improvement in NYHA functional class and left ventricular ejection fraction. The lead measurements were mainly stable over time., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Objectives: This study sought to compare long-term arrhythmia-free survival between electrical circumferential pulmonary vein isolation (PVI) and PVI with the endpoint of unexcitability along the ablation line., Background: PVI is the standard ablation strategy of paroxysmal atrial fibrillation, although arrhythmia recurrence in long-term follow-up (FU) is high. The endpoint of unexcitability along the ablation line results in decreased arrhythmia recurrence compared to electrical PVI in 1-year FU., Methods: Seventy-four consecutive patients (age 62.5 ± 10.6 years; 70.3% male) with de novo paroxysmal atrial fibrillation who were initially included in our randomized trial and underwent catheter ablation at our institution were analyzed. Patients who were randomized to either a conventional group (PVI, guided by circumferential catheter signals) or a pace-guided group (PG, anatomical ablation line encircling, ablation until loss of pace capture at 10 V, 2-ms pulse width on the ablation line) underwent long-term FU. The primary endpoint was recurrence of any atrial fibrillation or atrial tachycardia after a blanking period of 3 months., Results: Sixty-nine patients completed a mean FU period of 5.14 ± 0.98 years. Arrhythmia-free survival without antiarrhythmic drug therapy was significantly higher in the PG group (71.05% vs. 25.81%, p = 0.002). Furthermore, multiple procedure success (1.29 ± 0.61 procedures in PG vs. 1.97 ± 1.06 procedures in conventional group, p < 0.001) was higher in the PG group compared to the conventional group (89.47% vs. 58.06%, p = 0.005)., Conclusions: The endpoint of unexcitability along the PVI line improves success rates, resulting in a significant reduction of exposure to invasive procedures in 5-year FU., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Propofol sedation has been shown to be safe for atrial fibrillation ablation and internal cardioverter-defibrillator implantation but its use for catheter ablation (CA) of ventricular tachycardia (VT) has yet to be evaluated. Here, we tested the hypothesis that VT ablation can be performed using propofol sedation administered by trained nurses under a cardiologist's supervision., Methods and Results: Data of 205 procedures (157 patients, 1.3 procedures/patient) undergoing CA for sustained VT under propofol sedation were analysed. The primary endpoint was change of sedation and/or discontinuation of propofol sedation due to side effects and/or haemodynamic instability. Propofol cessation was necessary in 24 of 205 procedures. These procedures (Group A; n = 24, 11.7%) were compared with those with continued propofol sedation (Group B; n = 181, 88.3%). Propofol sedation was discontinued due to hypotension (n = 22; 10.7%), insufficient oxygenation (n = 1, 0.5%), or hypersalivation (n = 1, 0.5%). Procedures in Group A were significantly longer (210 [180-260] vs. 180 [125-220] min, P = 0.005), had a lower per hour propofol rate (3.0 ± 1.2 vs. 3.8 ± 1.2 mg/kg of body weight/h, P = 0.004), and higher cumulative dose of fentanyl administered (0.15 [0.13-0.25] vs. 0.1 [0.05-0.13] mg, P < 0.001), compared with patients in Group B. Five (2.4%) adverse events occurred., Conclusion: Sedation using propofol can be safely performed for VT ablation under the supervision of cardiologists. Close haemodynamic monitoring is required, especially in elderly patients and during lengthy procedures, which carrying a higher risk for systolic blood pressure decline., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Aims: Pulmonary vein isolation (PVI) is an effective treatment option for paroxysmal atrial fibrillation (PAF). Reconnection of pulmonary veins (PVs) is the predominant cause for recurrence of PAF. However, treatment of patients with recurrence of PAF despite isolated PV in the absence of extra-PV foci remains challenging., Methods and Results: Of 265 patients undergoing repeat catheter ablation (CA) for recurrence of PAF 21 (8%) patients (14 men, age 58 ± 14 years) showed no reconnection of PV. Therefore, inducibility of sustained atrial arrhythmias was tested. If sustained atrial fibrillation (AF) or sustained atrial tachycardia (AT) was induced, patients underwent CA. During follow-up (FU), Holter- and Tele-electrocardiogram were performed. In 19 (91%) of 21 patients, sustained atrial arrhythmias [16 (84%) AF; 3 (15%) patients AT] were induced. One patient showed PAF. Eighteen patients underwent CA aiming for termination of induced arrhythmia. In 14 (77%) patients, termination into sinus rhythm was achieved. Despite extensive CA, three (16%) patients were externally cardioverted. No periprocedural complications occurred. During 21.2 ± 6.8-month FU, 10 (53%) patients were free of any arrhythmia. Paroxysmal atrial fibrillation recurred in 4 (21%) and AT in 5 (26%) patients. One patient showed persistent AF. Repeat CA was scheduled and successfully performed for these patients., Conclusion: In patients with recurrence of PAF despite isolated PV, termination of induced atrial arrhythmias can be achieved in most patients by defragmentation and AT ablation. Moreover, this ablation strategy results in favourable mid-term outcome results., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Background: Long-term success rates using ablation for persistent atrial fibrillation (AF) are disappointing and usually do not exceed 60%., Objectives: This study sought to compare arrhythmia-free survival between pulmonary vein isolation (PVI) and a stepwise approach (full defrag) consisting of PVI, ablation of complex fractionated electrograms, and additional linear ablation lines in the setting of atrial tachycardias (AT) in patients with persistent AF after PVI., Methods: From November 2010 to February 2013, 205 patients (151 men; 61.7 ± 10.2 years of age) underwent de novo ablation for persistent AF. Subsequently, patients were prospectively randomized to either PVI alone (n = 78) or full defrag (n = 75), with 52 patients not randomized due to AF termination with the original PVI. The primary endpoint was recurrence of any AT after a blanking period of 3 months., Results: During the entire study, 241 ablations were performed (mean: 1.59 in the PVI-alone group, 1.55 in the full-defrag group). With the stepwise approach, termination of AF occurred in 45 (60%) patients. However, arrhythmia-free survival did not differ whether patients underwent single or multiple procedures (p = 0.468). Procedure duration, fluoroscopy time, and radiofrequency duration were significantly longer in the full-defrag group (all p < 0.001)., Conclusions: A stepwise approach aimed at AF termination does not seem to provide additional benefit over PVI alone in patients with persistent AF, but it is associated with significantly longer procedural and fluoroscopic duration as well as radiofrequency application time. (The Randomized Catheter Ablation of Persist End Atrial Fibrillation Study [CHASE-AF]; NCT01580124)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: In the meantime, catheter ablation is widely used for the treatment of persistent atrial fibrillation (AF). There is a paucity of data about long-term outcomes. This study evaluates (1) 5-year single and multiple procedure success and (2) prognostic factors for arrhythmia recurrences after catheter ablation of persistent AF using the stepwise approach aiming at AF termination., Methods and Results: A total of 549 patients with persistent AF underwent de novo catheter ablation using the stepwise approach (2007-2009). A total of 493 patients were included (Holter ECGs ≥ every 6 months). Mean follow-up was 59 ± 16 months with 2.1 ± 1.1 procedures per patient. Single and multiple procedure success rates were 20.1% and 55.9%, respectively (80% off antiarrhythmic drug). Antiarrhythmic drug-free multiple procedure success was 46%. Long-term recurrences (n=171) were paroxysmal AF in 48 patients (28%) and persistent AF/atrial tachycardia in 123 patients (72%). Multivariable recurrent event analysis revealed the following factors favoring arrhythmia recurrence: failure to terminate AF during index procedure (hazard ratio [HR], 1.279; 95% confidence interval [CI], 1.093-1.497; P = 0.002), number of procedures (HR, 1.154; 95% CI, 1.051-1.267; P = 0.003), female sex (HR, 1.263; 95% CI, 1.027-1.553; P = 0.027), and the presence of structural heart disease (HR, 1.236; 95% CI, 1.003-1.524; P = 0.047). AF termination was correlated with a higher rate of consecutive procedures because of atrial tachycardia recurrences (P = 0.003; HR, 1.71; 95% CI, 1.20-2.43)., Conclusions: Catheter ablation of persistent AF using the stepwise approach provides limited long-term freedom of arrhythmias often requiring multiple procedures. AF termination, the number of procedures, sex, and the presence of structural heart disease correlate with outcome success. AF termination is associated with consecutive atrial tachycardia procedures., (© 2015 American Heart Association, Inc.)

Background: The role of subsequent atrial tachycardias (AT) in the context of persistent atrial fibrillation (AF) remains undetermined. This study evaluated the prognostic role of subsequent ATs for arrhythmia recurrences after catheter ablation of persistent AF., Methods and Results: A total of 110 patients with persistent AF (63±9 years; 22 women; 61 long-lasting persistent AF) underwent pulmonary vein isolation followed by electrogram-guided ablation. After AF terminated to AT, patients were separated by the randomization protocol to receive either direct cardioversion (group A) or further ablation of subsequent ATs to sinus rhythm (group B). After a mean follow-up of 20.1±13.3 months after the first procedure, significantly more group B patients were in sinus rhythm as compared with patients in group A (30 [57%] versus 18 [34%]; P=0.02). Moreover, recurrences of AF were significantly less frequent of group B than in group A patients (10 [19%] versus 26 [49%]; P=0.001). After the last procedure (follow-up, 34.0±6.4 months), significantly more group B patients were free of AF as compared with patients of group A (49 [92%] versus 39 [74%]; P=0.01). The proportion of AT recurrences did not differ between the 2 groups after the first and final procedures. The strongest predictor for an arrhythmia-free survival after a single procedure was randomization to the procedural end point of termination to sinus rhythm by elimination of subsequent ATs (P=0.004)., Conclusions: Catheter ablation of subsequent ATs increases freedom from AF but not AT, suggesting a contributing role of subsequent ATs in the mechanisms of persistent AF., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01896570.

Objectives: This study was conducted to determine if an additional procedural endpoint of unexcitability (UE) to pacing along the ablation line reduces recurrence of atrial fibrillation (AF) or atrial tachycardia (AT) after radiofrequency catheter ablation., Background: AF/AT recurrence is common after pulmonary vein isolation (PVI)., Methods: We included 102 patients from 2 centers (age 63 ± 10 years; 33 women; left atrium 38 ± 7 mm; left ventricular ejection fraction 61 ± 6%) with symptomatic paroxysmal AF. A 3-dimensional mapping system and circumferential mapping catheter were used in all patients for PVI. In group 1 (n = 50), the procedural endpoint was bidirectional block across the ablation line. In group 2 (n = 52), additional UE to bipolar pacing at an output of 10 mA and 2-ms pulse width was required. The primary endpoint was freedom from any AF/AT (>30 s) after discontinuation of antiarrhythmic drugs., Results: Procedural endpoints were successfully achieved in all patients. Procedure duration was significantly longer in group 2 (185 ± 58 min vs. 139 ± 57 min; p < 0.001); however, fluoroscopy times were not different (23 ± 9 min vs. 23 ± 9 min; p = 0.49). After a follow-up of 12 months in all patients, 26 patients (52%) in group 1 versus 43 (82.7%) in group 2 were free from any AF/AT (p = 0.001) after a single procedure. No major complications occurred., Conclusions: The use of pacing to ensure UE along the PVI line markedly improved near-term single-procedure success, compared with demonstration of bidirectional block alone. This additional endpoint significantly improved patient outcomes after PVI. (Unexcitability Along the Ablation as an Endpoint for Atrial Fibrillation Ablation; NCT01724437)., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: The aim of this study was to assess the role of a non-pharmacological approach on the frequency of traumatic injuries and syncope recurrence in patients with vasovagal syncope and normal hearts. We report the experience in our syncope centre with a standardized education and teaching protocol for patients with vasovagal syncope. The treatment of vasovagal syncope is often complex and discouraging. Besides medical options, behaviour modification is a main component of therapy but has no statistical evidence to support its use., Methods and Results: Between January 1999 and September 2006, we prospectively enrolled all patients with vasovagal syncope. The patients were counselled about the benign nature of their disease. Specific recommendations were made according to a standardized education protocol established at our syncope centre. A pre-/post-study was conducted to investigate the effectiveness of our approach on syncope recurrence and frequency of injury as the study endpoints. Complete follow-up data were available from 85% of the study population (316 of 371) after a mean time of 710 ± 286 days (mean age 50 years; standard deviation ± 18 years, 160 female). Eighty-seven patients (27.5%) had a syncope recurrence with 22 suffering an injury during syncope. During the follow-up period, the syncope burden per month was significantly reduced from 0.35 ± 0.03 at initial presentation to 0.08 ± 0.02 (P< 0.001). The frequency of traumatic syncope was significantly lower at the time of recurrence compared with the initial presentation (25 vs. 42%; McNemar's test P= 0.02)., Conclusion: A standardized education protocol significantly reduces traumatic injuries and syncope recurrence in patients with vasovagal syncope.

Background: Termination of persistent atrial fibrillation (AF) can be achieved through ablation, with the majority of patients terminating to an atrial tachycardia (AT) and fewer directly to sinus rhythm (SR). We aimed to identify potential predictors for the existence of a substrate for AT on termination to SR., Methods and Results: We assessed 95 persistent AF patients (age, 60+/-10 years) who underwent catheter ablation to the end point of AF termination. Forty patients terminated directly to SR (SRterm) and 55 to ATs (ATterm). Compared with the ATterm group, the SRterm group were younger (56+/-10 versus 63+/-9 years, P=0.001), had shorter durations of AF before ablation (9+/-26 versus 14+/-20 months, P<0.001), smaller left atrial diameters (41+/-5 versus 45+/-5 mm, P=0.015), and longer baseline AF cycle lengths (178+/-23 versus 159+/-31 ms, P=0.005). However, AF cycle length was the sole independent predictor of direct termination to SR. The most frequent AF termination site in SRterm patients was the pulmonary veins (53%), whereas in ATterm patients this was within the left atrium (58%). After follow-up of 12+/-6 months, there was a trend toward a greater proportion of patients in SR among those who terminated directly to SR after a single procedure. The most frequent type of recurrence was paroxysmal AF in SRterm patients and AT in ATterm patients., Conclusions: Patients who terminate to SR through ablation without an intermediate AT are characterized by a less altered arrhythmogenic substrate. Baseline AF cycle lengths emerged as a sole independent predictor of a substrate for consecutive arrhythmias.

Background: Atrial tachycardias (AT) often occur after ablation of long-lasting persistent AF (CAF) and are difficult to treat conservatively. This study evaluated mechanisms and success rates of conventional mapping and catheter ablation of recurrent ATs occurring late after stepwise ablation of CAF., Methods and Results: A total of 320 patients underwent de novo ablation of CAF using a stepwise ablation approach in 2006 to 2007 at our institution. This study comprised patients who presented with recurrent ATs at their first redo procedure after initial de novo CAF ablation. All procedures were guided by conventional mapping techniques exclusively. Sixty-one patients (63+/-10 years, 14 women) presented with their clinical AT at their redo procedure 7.7+/-4.4 months after initial de novo CAF ablation. A total of 133 ATs (2.2+/-0.9 per patient) were mapped. Forty-four (72%) were due to reentry; 17 (28%) were focal ATs. Reentry ATs were mainly characterized as roof and perimitral flutter (43% and 34%, respectively). Focal ATs mainly originated from the great thoracic veins (pulmonary veins: 41%, coronary sinus: 23%). Forty-five (74%) patients had conduction recovery of at least 1 pulmonary vein (mean, 1.2+/-0.8). Overall, 124 (93%) ATs could be ablated successfully. The mean procedure duration was 181+/-59 minutes, with a mean fluoroscopy time of 45+/-21 minutes. After a mean follow-up of 21+/-4 months, 50 (82%) patients were free of any arrhythmia recurrences after a single redo procedure., Conclusions: Although late recurrent ATs may have complex mechanisms, catheter ablation guided exclusively by conventional techniques is highly effective with excellent acute and long-term success rates.

Background: Termination of chronic atrial fibrillation (CAF) can be achieved by catheter ablation using a stepwise approach. However, there are limited data on the contribution of the right atrium to the CAF process. Furthermore, the prognostic value of CAF termination remains unclear., Methods and Results: Eighty-eight patients (61+/-10 years of age) underwent de novo ablation of CAF in 2006 at our institution. The ablation procedure was performed sequentially in the following order: pulmonary vein isolation, defragmentation of the left atrium, coronary sinus, and right atrium. Attempted procedural end point was termination of CAF. Consecutive arrhythmias occurring after AF termination were mapped, and ablation was attempted. AF termination was achieved in 68 (77%) patients: in 37 (55%) patients it occurred in the left atrium, in 18 (26%) patients in the right atrium, and in 13 (19%) patients in the coronary sinus. In 54 patients, at least one redo was performed (total number of procedures: 154). After the first redo, another 30 patients were in sinus rhythm (total 63), 8 patients were in atrial tachycardia (AT), and 17 patients were in AF. Another 11 patients underwent a second redo. After a mean follow-up of 20+/-4 months, 71 (81%) patients were in sinus rhythm, 1 (1%) patient was in AT, and 16 (18%) patients were in AF. Patients with CAF termination had predominantly ATs as recurrent arrhythmias (83%), whereas those without mainly presented with recurrent CAF (85%). The overall success rate in patients with CAF termination was 95% compared with 5% of patients without CAF termination in 2 procedures (n=12). In almost all redo procedures attributable to AT, at least 1 AT during redo was documented previously., Conclusions: AF termination is a prognostic important end point of catheter ablation for CAF. Termination of AF was achieved in both atria and the coronary sinus, suggesting a biatrial substrate of CAF. Subsequent arrhythmias often recur during follow-up and, therefore, should be targeted for ablation.