Background: Cryoballoon ablation is a well-established method for pulmonary vein isolation (PVI) in patients with paroxysmal and persistent atrial fibrillation (AF). However, long-term data describe that up to 27% of pulmonary veins are reconnected, which promotes recurrence of AF. Acute PVI performed with the latest 4th generation cryoballoon catheter has not been well studied. Therefore, this study aims to investigate the efficacy of the latest 4th generation cryoballoon catheters using ultra high-resolution mapping.

Methods: In patients with AF, a standard PVI with the latest 4th generation cryoballoon catheter (Arctic Front Advance PRO, Medtronic Minneapolis, USA) and the newest inner lumen mapping catheter (Achieve Advance, Medtronic, Minneapolis, MN, USA) was performed.  Subsequently, ultra-high-resolution mapping was achieved using the novel multipolar grid mapping catheter (Advisor HD Grid SE, Abbott Laboratories; USA). Follow-up was obtained after 6 months by means of a 7-day Holter ECG.

Results: In our study, acute PVI was successfully achieved in all patients (n = 31). Additional ultra-high-resolution mapping (mean points per map 21001 ± 4911) revealed no gaps on the ablated areas. Therefore, no additional ablation was performed. In 6 months, follow-up 3 patients (10%) experienced recurrence of AF. Redo procedures revealed new reconnections sites in both pulmonary vein pairs.

Conclusion: The PVI with the latest 4th generation cryoballoon catheters has an excellent effectiveness in the acute phase. However, our study cohort also revealed a proportion of patients with reconnection of pulmonary veins and recurrence of AF. Our study suggests that the use of ultra-high-resolution mapping has no additional benefit and is not able to identify pulmonary veins in which reconnection will occur.