Acute impact of vein of marshall ethanol infusion combined with anatomical ablation validated by pacing in redo ablation of persistent atrial fibrillation
Authors: Nesti M , Rossi A , Garibaldi S , Panchetti L , Mirizzi G , Startari U , Valleggi A , Marchese P , Piacenti M 
Published: May 2024

Abstract

Background
Catheter ablation with radiofrequency in persistent atrial fibrillation (PeAF) has limited success and a significant proportion of patients requires redo ablation. Several trials showed that addition of vein of Marshall ethanol infusion (Vom-EI) to catheter ablation, compared with catheter ablation alone, increases the possibilities of remaining free of AF. No data are available about the effect on VoM-EI in Pe-AF patients that undergo a redo ablation.

Purpose
We evaluated acute impact on lesion formation post-VoM-EI and the mitral line block validation after a methodical approach including VoM-EI and check of pulmonary vein isolation (PVI), roof-line, mitral line (ML) and cavo-tricuspid isthmus line in a population of PeAF patients undergone redo ablation. We aimed also the results of a short follow-up.

Methods
Consecutive patients undergoing redo ablation for PeAF were enrolled. All patients underwent check of PVI, left atrium (LA) roofline and cavotricuspid isthmus line and, if necessary, ablation was completed. In all patients, after a detailed electroanatomical map of the LA (filter at 0.05-0.5 mV if the patient was in sinus rhythm or 0.05-0.3 mV in the case of AF), we proceeded with the VoM-ETHO. LA map was thus repeated to assess the extension of the newly-formed low voltage area (LVA). According to the newly-formed LVAs, the validation of mitral line was obtained by the evidence of bidirectional block. In presence of conduction through the mitral line also after endocardial revision, we proceeded to mapping and ablating in the CS epicardial gaps in the "anchored wall" or in the "free-wall"of the great cardiac vein (GCV).

Results
Twenty consecutive patients (64±8 years and 65% male) undergone redo ablation for AF with VoM-EI were included in this study. All patients underwent PVI in the previous procedure but only in 11 roof line has been performed. In twenty patients (52%) reconnection of PV was observed (12/20 in right superior pulmonary vein). In 4/11 roof line was not complete. The medium value of basal LA-LVAs was 3.38土5.27 cmq and the newly-formed LVAs after the VoM-EI procedure was 9.21土5.63 cmq. All patients achieved bidirectional block validated across ML: in 8/20 after epicardial gaps ablations into the anchored wall of GCV and in 6/20 after epicardial gaps ablation in the free wall of GCV. The ML procedural time was 18.82土12.79 minutes. The number of radiofrequency irrigation was 20.11土10.56. No major complications occurred. Five patients had VOM dissection without consequences. During a short follow-up period (6土5 months), only one patient had AF recurrences after the blanking period of one month.

Conclusions
VoM ethanol ablation added to PVI and linear lesions in the context of a methodical and anatomical approach during redo ablation of PeAF patients seems to have promising results and to be safe. Longer follow-up is needed to understand the role of this technique in redo ablation.