Catheter ablation (CA) of atrial fibrillation (AF) is currently one of the most commonly performed electrophysiology procedures. Ablation of paroxysmal AF is based on the elimination of triggers by pulmonary vein isolation (PVI), while different strategies for additional AF substrate modification on top of PVI have been proposed for ablation of persistent AF. Nowadays, various technologies for AF ablation are available. The radiofrequency point-by-point ablation navigated by electro-anatomical mapping system and cryo-balloon technology are comparable in terms of the efficacy and safety of the PVI procedure. Long-term success of AF ablation including multiple procedures varies from 50 to 80%. Arrhythmia recurrences commonly occur, mostly due to PV reconnection. The recurrences are particularly common in patients with non-paroxysmal AF, dilated left atrium and the "early recurrence" of AF within the first 2–3 post-procedural months. In addition, this complex procedure can be accompanied by serious complications, such as cardiac tamponade, stroke, atrio-esophageal fistula and PV stenosis. Therefore, CA represents a second-line treatment option after a trial of antiarrhythmic drug(s). Good candidates for the procedure are relatively younger patients with symptomatic and frequent episodes of AF, with no significant structural heart disease and no significant left atrial enlargement. Randomized trials demonstrated the superiority of ablation compared to antiarrhythmic drugs in terms of improving the quality of life and symptoms in AF patients. However, nonrandomized studies reported additional clinical benefits from ablation over drug therapy in selected AF patients, such as the reduction of the mortality and stroke rates and the recovery of tachyarrhythmia-induced cardiomyopathy. Future research should enable the creation of more durable ablative lesions and the selection of the optimal lesion set in each patient according to the degree of atrial remodeling. This could provide better long-term CA success and expand indications for the procedure, especially among the patients with non-paroxysmal AF.

Reliable prediction of very late recurrence of atrial fibrillation (VLRAF) occuring >12 months after catheter ablation (CA) in apparently “cured” patients could optimize long-term follow-up and modify decision-making regarding the discontinuation of oral anticoagulant therapy. In a single-centre cohort of consecutive patients post radiofrequency AFCA, we retrospectively derived a novel score for VLRAF prediction. Of 133 consecutive post AFCA patients (mean age 56.9 ± 11.8 years, 63.9% male, 69.2% with paroxysmal AF) who were arrhythmia-free at 12 months (excluding 3-month “blanking period”), 20 patients expirienced a VLRAF during a 29.1 ± 10.1-month follow-up, with a 3-year cumulative VLRAF rate of 31.1%. The MB-LATER score (Male, Bundle brunch block, Left atrium ≥47 mm, Type of AF [paroxysmal, persistent or long-standing persistent], and ER-AF = early recurrent AF), had better predictive ability for VLRAF (AUC 0.782) than the APPLE, ALARMc, BASE-AF2, CHADS₂, CHA₂DS₂VASc or HATCH score (AUC 0.716, 0.671, 0.648, 0.552, 0.519 and 0.583, respectively), resulted in an improved net reclassification index (NRI) of 48.6–95.1% and better identified patients with subsequent VLRAF using decision-curve analysis (DCA). The MB-LATER score provides a readily available VLRAF risk assessment, and performs better than other scores. Validation of the MB-LATER score in other cohorts is underway.

Introduction Cardiac tamponade (CT) is a life-threatening complication of radiofrequency ablation (RFA). The course and outcome of CT in low-to-medium volume electrophysiology centers are underreported. Methods We analyzed the incidence, management and outcomes of CT in 1500 consecutive RFAs performed in our center during 2011–2016. Results Of 1500 RFAs performed in 1352 patients (age 55 years, interquartile range: 41–63), 569 were left-sided procedures (n = 406 with transseptal access). Conventional RFA or irrigated RFA was performed in 40.9% and 59.1% of procedures, respectively. Ablation was performed mostly for atrioventricular nodal reentrant tachycardia (25.4%), atrial fibrillation (AF; 18.5%), atrial flutter (18.4%), accessory pathway (16.5%) or idiopathic ventricular arrhythmia (VA; 12.3%), and rarely for structural VA (2.1%). CT occurred in 12 procedures (0.8%): 10 AF ablations, 1 idiopathic VA and 1 typical atrial flutter ablation. Factors significantly associated with CT were older age, pre-procedural oral anticoagulation, left-sided procedures, transseptal access, AF ablation, irrigated RFA and longer fluoroscopy time (on univariate analysis), and AF ablation (on multivariable analysis). The perforation site was located in the left atrium (n = 7), right atrium (n = 3), or in the left ventricle or coronary sinus (n = 1 each). Upon pericardiocentesis, two patients underwent urgent cardiac surgery because of continued bleeding. There was no fatal outcome. During the follow-up of 19 ± 14 months, eight patients were arrhythmia free. Conclusion Incidence of RFA-related CT in our medium-volume center was low and significantly associated with AF ablation. The outcome of CT was mostly favorable after pericardiocentesis, but readily accessible cardiothoracic surgery back-up should be mandatory in RFA centers.

Early recurrence of atrial fibrillation (ERAF) after catheter-ablation (CA) can be a transient phenomenon due to inflammation, or a harbinger of late AF recurrence due to CA lesion (re)conduction. We studied the relationship between ERAF and the 3-month CA lesions integrity. Forty one consecutive AF patients who underwent a pulmonary vein isolation (PVI), roof line (RL) and mitral isthmus line (MIL) CA were enrolled. At 3 months all patients underwent invasive assessment of the lesion set integrity irrespective of ERAF. The PVI, RL and MIL ablation was successful in 100.0%, 95.1% and 82.9% patients, respectively. At the 3-month remapping, a gap in PVI-lesion(s), RL or MIL was identified in 61.0%, 31.7% and 36.6% patients, respectively. Patients with (n = 17, 41.5%) compared to those without ERAF (n = 24) had a significantly higher rate of any PV-reconnection (88.2% vs. 41.7%), the right PV(s)-reconnection (82.5% vs. 29.2%) and the RL gap (52.9% vs. 16.7%), as well as a higher number of reconnected right PVI-segments, all p < 0.05. On multivariate analysis, only the number of reconnected right PVI-segments was associated with ERAF (OR 4.26, p = 0.004). The ERAF following PVI + RL + MIL ablation was significantly related to 3-month PV-reconnections and the presence of RL gaps.