Introduction
Catheter ablation (CA) is a pivotal component of the rhythm control
strategy in patients with symptomatic atrial fibrillation
(AF).1,2 Pulmonary vein isolation (PVI) is well
established as the cornerstone procedural target in case of a first AF
ablation, due to the prominent role played by pulmonary veins in
arrhythmia initiation in paroxysmal AF.1,2
However, procedural outcomes are still suboptimal in patients with
persistent AF, and in these subjects additional anatomical structures
and/or electrophysiological triggers are commonly ablated on top of PVI,
in an attempt to improve ablation effectiveness.2-5
In recent years, we have witnessed a renewed interest in atrial anatomy
and in the role of epicardial structures, such as Bachmann’s bundle (BB)
and the ligament of Marshall (LOM), as critical determinants of
AF.6,7 At the same time, percutaneous epicardial
ablation has gained popularity as an important component of the
therapeutic armamentarium for ventricular
tachycardia.8
Driven by the desire to address arrhythmogenic epicardial structures
while avoiding complications related to a thoracotomic approach,
minimally invasive epicardial ablation for AF has now entered the
clinical arena, and some preliminary experiences supported its
feasibility and allowed a greater understanding of the transmurality of
the AF substrate, with encouraging clinical
results.9-11
Based on these preliminary observations, we developed a combined
endo-/epicardial stepwise protocol for AF CA in patients with persistent
or longstanding persistent AF and one or more prior endocardial
procedures, the Mediterranea approach. In the present study, we describe
our protocol in detail, focusing on technical aspects of the epicardial
approach to relevant atrial structures, providing insights into the
sites of AF termination, and reporting clinical outcomes.