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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
212
Ablation of pulmonary veins reconnections plus the search and ablation of hidden slow conductions sites (HSC) in the left atrium. HSC sites are defined as EGMs showing highly fragmented or double electrograms in response atrial triple extrastimulus, presenting normal or fractionated electrogram in the sinus rhythm. After checking for PV's conduction breakthroughs, point-by point ablation targeting HSC-EGMs will be performed. The end point for HSC+ ablation will be reached with loss of local capture at a given lesion, pacing from the ablation catheter at high output (10V·2ms).
Each vein will be re-assessed by observing PV potentials along the PV ostia and by pacing from the distal bipole of the ablation catheter (10mA at 2ms) within the lesion set with failed capture of the left atrium. In case of PVs reconnection touch-up applications will be performed at the earliest potential site, identified by comparing far-field atrial EGM to near-field local EGM timing, until isolation will be achieved (entrance and exit block).
Atrial arrhythmias recurrence
The primary endpoint of the study aims to establish the impact of targeting HSC sites alongside PV gaps in repeat ablation procedures for patients with recurrent AF. Specifically evaluating the freedom from atrial tachyarrhythmia recurrence (documented AF/AT/AFL lasting at least 30s).
Time frame: up to 12 moths
Burden of atrial arrhythmias
Arrhythmic burden (average percentage of time in AF/AT in 24h Holter)
Time frame: up to 12 moths
incidence of periprocedural complications (pericardial effusion)
incidence of periprocedural complications such as pericardial effusion
Time frame: up to 12 months
Use of antiarrhythmic drugs
Use of antiarrhythmic drugs after the blanking period of 60 days.
Time frame: up to 12 months
incidence of periprocedural complications (peripheral complication)
incidence of periprocedural complications such as peripheral complication
Time frame: up to 12 moths
incidence of periprocedural complications (transient ischemic attack or stroke)
incidence of periprocedural complications such as transient ischemic attack or stroke
Time frame: up to 12 months
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