Background: Data on sex-related outcomes of pulmonary vein isolation (PVI) of cryoballoon ablation (CBA) in atrial fibrillation (AF) are sparse. Aim: To compare sex-differences in PV reconnection, strategy and outcome of repeat ablations after CBA. Methods: Repeat procedures were performed using radiofrequency ablation guided by 3D mapping. PV reconnection characteristics were compared in 229 patients (77 (33.6%) females). In durable PVI patients, we compared left atrial voltage maps, ablation strategy and 1-year outcome. Clinical success was defined as freedom of documented AF or atrial tachycardia (AT) >30s. Results: Female patients had a lower overall number of PV reconnections (0.8±0.9 vs 1.2±1.0, P<0.001) driven by less reconnected left PVs: 13/77 (16.9%) vs 51/152 (33,6%), P=0.008 and 7/77 (9.1%) vs 39/152 (25.7%), P=0.003 for LSPV and LIPV, respectively. Durable PVI was more frequent in women (34/77 (44.1%) vs 37/152 (24.4%), P=0.001). Female sex was the only independent predictor for durable PVI (HR=2.003; 95%CI 1.090-3.682; P=0.025). In durable PVI patients, substrate ablation was more frequently performed in women (21/35 (60%) vs 13/35 (37.1%), P=0.044), mainly targeting the higher prevalent atrial low-voltage zones (21/35 (60.0%) vs 12/36 (33.3%), P=0.017). At 1 year, recurrence of AF/AT did not differ between sexes: 6/35 (17.1%) vs. 8/35 (22.9%), P=0.591. Conclusions: The higher persistence of durable PVI in women points to a sex difference in AF recurrence driver after CBA. In durable PVI patients, a higher prevalence of low-voltage regions results in more substrate ablation in women. Despite sex differences in ablation strategy, 1-year outcome was similar.

We describe the first case of cryoballoon (CB) pulmonary vein isolation (PVI) facilitated by perioperative electroanatomical mapping (EAM) in a patient with dextrocardia due to Kartagener’s syndrome and highly symptomatic paroxysmal atrial fibrillation. Current case report highlights the different advantages of the addition of EAM to CB ablation for AF. This approach is feasible strategy for rhythm control in patients with atrial fibrillation and Kartagener’s syndrome for which medication can be contra-indicated.

Background: Literature reports 5% of recurrence/ failure in pediatric accessory pathway ablations. Our aim was to investigate the reasons underlying this finding and share techniques to obtain long term success. Methods: Thirty-nine pediatric patients referred for a repeat procedure were analyzed: characteristics of the pathways and the initial and redo procedures were identified. Results: Mean age was 11.9 ± 3.3 years (59% males). Three patients (8%) had multiple accessory pathways. The most frequent location was left lateral (26%). Left sided pathway recurrence was caused mainly by poor contact (60%) and inadequate mapping (40%). For right lateral accessory pathways, poor contact accounted for 70% of failures. For antero-septal and para-hisian locations, the use of cryoablation and choice of low radiofrequency energy delivery accounted for > 75% of failures. Long-term success strategies included choice of contact force catheters and radiofrequency applications at the ventricular insertion of the pathway and in the aortic coronary cusps. In postero-septal substrates, the main reason accounting for failure was deep or epicardial location of the pathway (37%), solved by using an irrigated tip catheter or applying lesions within the coronary sinus, or applications from both right and left postero-septal areas. Conclusion: Acute failure and post-procedure recurrence in pediatric accessory pathway ablations have multiple reasons related to the characteristics of the pathway and the technology available. Accurate understanding of the anatomy, careful mapping and pacing maneuvers, and incorporation of new technologies contribute to achieve a definitive success in > 98% of procedures.