Hidden Slow Conduction Ablation for Recurrent Atrial Fibrillation: Unmasking the Arrhythmogenic Substrate (Unmask-AF)

Over recent years, pulmonary vein isolation (PVI) procedures have demonstrated progressively enhanced efficacy and safety, resulting in a substantial increase in the number of atrial fibrillation ablations, not only as a first-line treatment but also for repeat procedures. However, there is still a notable lack of randomized evidence in this area, which limits guidance and decision-making in clinical practice. Recently, the investigators found that employing short-coupled atrial extrastimuli revealed highly fragmented or double atrial evoked electrograms (EGMs) in AF patients, termed as hidden slow conduction (HSC). Identifying HSC sites may provide insight into the early identification of the arrhythmogenic substrate, offering a potential target for ablation This multi-center, prospective, randomized, controlled trial will include two arms: one investigational (PV reconnection + HSC) and one control (PV reconnection). All the subjects will be followed for 12 months after the ablation procedure. The aim of our study is to investigate the impact of ablating HSC sites on arrhythmia recurrence in repeat ablation procedures. The hypothesis is that the additional ablation of HSC zones may improve the freedom from atrial arrhythmia recurrence after repeat ablation procedure.

NCT Number	NCT06657170
Lead Sponsor	Centro Medico Teknon
Conditions	Atrial Fibrillation
Enrollment	212 participants
Start Date	2024-12
Primary Completion	2026-09 (estimated)
Study Completion	2027-09 (estimated)
Updated on ClinicalTrials.gov	2024-12-12