1 | INTRODUCTION
Endocardial radiofrequency catheter ablation of the mitral isthmus is
commonly performed for peri-mitral reentrant tachycardia or as part of
ablation strategy for persistent atrial
fibrillation.1,2 Ablation of the mitral isthmus is
challenging due to the anatomical complexity and the thickness of the
tissue in this region, and because of epicardial cooling by the coronary
sinus (CS) and circumflex artery.3 With both
endocardial and epicardial ablation from inside the CS, acute complete
bi-directional block of the mitral isthmus is achieved in only about
70% of patients.4,5
The ligament of Marshall is an epicardial vestigial fold that contains
the vein of Marshall (VOM) and the Marshall bundle.6The VOM drains into the CS and runs posteriorly and superiorly along the
epicardial surface of the left atrium, to join the anterior aspect of
the left-sided pulmonary veins. Myofibers of the VOM can form an
epicardial bridge over the mitral isthmus, preventing successful
ablation from the endocardium and from within the CS.7
In 2009, Valderrabano et al. first described chemical ablation of the
VOM by retrograde infusion of ethanol into the VOM (VOM-EI) and showed
that VOM-EI can facilitate mitral isthmus ablation.8,9Subsequently, other groups adopted and refined the technique of VOM-EI
for mitral isthmus ablation with high success rates.10Linear ablation of the mitral isthmus is an additional target of
ablation of persistent atrial fibrillation, and VOM-EI may be used in
these patients. The recent VENUS-trial, a prospective multicentre
randomized study, showed improved arrhythmia-free outcome in patients
with persistent atrial fibrillation treated with catheter ablation with
supplement ethanol infusion into the vein of
Marshall.11
The aim of the present study was to describe our single-centre
experience of efficacy and safety of VOM-EI for mitral isthmus ablation.