Introduction: Repeated procedures are often needed for long-term success of atrial fibrillation ablation. There are scarce data regarding cryoballoon use for such procedure. Methods and Results:We analyzed acute effect and long-term follow-up of secondgeneration cryoballoon ablation, performed as a repeat procedure after an index radiofrequency vs cryoballoon ablation. Sixty-one patients from three centers were included. In 36 cases radiofrequency (RF-I) and in 25 cryoballoon ablation (CB-I) was the index procedure. During redo procedure, pulmonary vein reconnection was less frequent in CB-I vs RF-I (51.5% vs 66.9%; P = 0.017). After cryoballoon, left inferior (P = 0.027) and right superior (P = 0.06) pulmonary veins were less likely to exhibit reconnection. Moreover, patients after initial RF ablation frequently presented multiple-vein reconnection (P = 0.018), while patients after cryoablation more often had only one vein reconnected (P = 0.008).During reablation procedures, all 149 reconnected veins in both groups were isolated, with no differences in procedural parameters, except for procedure time, shorter in CB-I group (65.5 vs 71.1 minutes; P = 0.04). Transient phrenic nerve palsy was the only complication in both groups (5.6% and 8.0%; ns). After mean follow-up of 15 ± 9 months, 70.3% of patients were free from atrial fibrillation (AF), with no differences between the groups (P = 0.71). In multivariate Cox-regression analysis, the persistent form of arrhythmia (P = 0.009) and relapse in the blanking period (P = 0.0004) were the only independent predictors of AF recurrence. Conclusions:The use of second-generation cryoballoon is associated with less frequent pulmonary vein reconnection compared with RF ablation. Cryoballoon is safe and effective for repeated AF ablation, regardless of the technique used for the initial procedure. K E Y W O R D S atrial fibrillation, cryoballoon ablation, pulmonary vein reconnection, redo ablation

Introduction: Silent cerebral infarcts (SCIs) detected by diffusion-weighted magnetic resonance (DW-MRI) following atrial fibrillation (AF) ablation have been reported, with the incidence of 1-38%. We aimed to compare the incidence of SCIs following AF ablation with four different technologies and analyze the risk factors. Material and methods: A total of 104 patients (mean age: 59.9 ±9.5 years, 68 males) with symptomatic AF, referred for ablation, were included in the study. The AF ablation was performed with irrigated radiofrequency pointby-point technique (RF group) in 24 patients, and with 3 different single-shot techniques: phased-RF (PVAC) in 46, second-generation cryoballoon (CB) in 24 and irrigated multipolar RF catheter (nMARQ) in 10 patients. In all patients DW-MRI was performed pre-and post-procedurally to evaluate the incidence of SCIs. Procedural parameters, complication rate and post-procedural SCI incidence were compared between the groups. Results: Procedure (167.1 vs. 110.5 vs. 106.0 vs. 141.5 min, p < 0.001), fluoroscopy (22.7 vs. 15.9 vs. 16.3 vs. 15.3 min, p = 0.048) and LA dwell (101.5 vs. 53.9 vs. 56.0 vs. 97.0 min, p < 0.001) times compared respectively between RF, PVAC, CB and nMARQ groups were significantly shorter with single-shot techniques. The number of new-onset SCIs was 4/24 (16.7%) in RF, 7/46 (15.2%) in PVAC, 1/24 (4.2%) in CB and 1/10 (10%) in the nMARQ group. Univariate analysis identified procedure duration (p = 0.02), lower LV ejection fraction (p = 0.03), persistent form of arrhythmia (p = 0.007) and intraprocedural cardioversion (p = 0.002) as risk factors of new-onset SCIs. Conclusions: Silent cerebral infarcts can be detected following AF ablation regardless of the technology used. Prolonged procedure time, lower ejection fraction, persistent form of arrhythmia and intraprocedural cardioversion increase the risk of SCIs.

PurposeInteratrial block (IAB) frequently coexists with sinus node disease and is considered a risk factor of left atrial dysfunction, atrial arrhythmias, and heart failure development. Conventional right atrial appendage (RAA) pacing impairs intra- and interatrial conductions and consequently prolongs P wave duration. Biatrial (BiA) pacing helps correct IAB, but its advantageous influence remains controversial. The aim of the study was to compare the effects of BiA and RAA pacing on cardiac hemodynamics and serum concentrations of inflammatory markers and neuropeptides.MethodsTwenty-eight patients with IAB and preserved atrio-ventricular conduction treated with BiA pacing were studied. Standard invasive hemodynamic measurements were performed during BiA and RAA pacings. Furthermore, the influence of 1 week of BiA and RAA pacing on neuropeptides: atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) and markers of inflammation: high sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and neopterin was examined.ResultsBiA pacing resulted in significant increase of cardiac output (CO) and reduction of pulmonary capillary wedge pressure. We demonstrated significantly lower concentrations of ANP, hs-CRP, IL-6, and neopterin after 1 week of BiA in comparison to RAA pacing. BNP levels remained unchanged.ConclusionsBiA pacing in comparison to RAA pacing improves hemodynamic performance in patients with IAB and preserved atrio-ventricular conduction. BiA pacing is associated with reduction of ANP and markers of inflammation (hs-CRP, IL-6, and neopterin).

Background Catheter ablation is a routine procedure in patients with WPW syndrome. Silent cerebral infarcts (SCI) detected in magnetic resonance imaging may be a complication of the ablation procedure, but it is well documented only in atrial fibrillation ablation. Ablation of left-sided accessory pathways (L-AP) has a similar target area, but WPW patients differ from those with atrial fibrillation, due to lower initial risk of cerebral embolic events. The aim of this study was to determine whether the ablation of left-sided accessory pathways carries the risk of SCI. Material/Methods Twenty consecutive patients with overt L-AP referred for RF ablation in our center were included in the study. An irrigated ablation catheter was used in 8 patients, and a non-irrigated ablation catheter was used in 12 patients. Diffusion-weighted magnetic resonance imaging was performed pre-procedurally and on the next day after the ablation in all patients. Results Ablation procedures were completed without complications and there were no neurological symptoms following the procedure, although in 2 patients (10%), post-procedural diffusion-weighted magnetic resonance revealed new acute silent cerebral infarcts. Both patients with new cerebral lesions were female, and a non-irrigated catheter was used in both cases. Conclusions This is the first study documenting the presence of silent cerebral infarcts after WPW ablation. Further investigations are needed to evaluate the risk of silent cerebral infarcts associated with L-AP ablation.

ARTICLE INFORMATION CONFLICT OF INTEREST AG received fees for proctoring and holding lectures from Medtronic and Abbott. Other authors declare no conflict of interest. OPEN ACCESS This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC-BY-NC-ND 4.0), allowing third parties to download articles and share them with others, provided the original work is properly cited, not changed in any way, distributed under the same license, and used for noncommercial purposes only.