Modification of Electrophysiological Properties of Pulmonary Veins and Adjacent Left Atrial Tissue by Radiofrequency Thermal Balloon Circumferential Ablation around the Pulmonary Vein Ostia: Correlation with Non-recurrence of Atrial Fibrillation

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Objective: The purpose of this study was to provide detailed information as to the modification of electrophysiological properties of pulmonary veins (PVs) and adjacent left atrial (LA) tissue caused by circumferential ablation (ABL) of superior and inferior pulmonary vein ostia using a novel radio-frequency balloon catheter (RBC), and to correlate such changes with recurrence or non-recurrence of atrial fibrillation (AF).
Background: Although isolation of the triggering foci in PVs using conventional ABL techniques is useful in the treatment of AF, ABL of PVs per se is time consuming and tends to be associated with high AF recurrence rate.
Methods and Results: Forty-nine patients with AF refractory to antiarrhythmic medication underwent circumferential ablation of PV-LA junction by RBC. Post ablation changes in electrophysiological properties around the PV ostia were studied with a basket catheter and were correlated with AF recurrence in 34 (1^st study) early cases (ablating 68 superior PVs) and 15 (2^nd study) later cases (53 superior and inferior PVs). Total elimination of PV potentials or PV-LA dissociation was achieved in 93% (63/68 PVs) and 93% (49/53 PVs), respectively. During mean follow-up periods of 24.1±4.1 and 13.3±1.7 months, AF recurred in 38% (13/34 cases) and 13% (2/15) in early and later groups, respectively, but no case developed severe PV stenosis. Although the amplitude of PV and periostial LA potentials were decreased (p<0.0001) in all patients, the remaining PV potentials in 34 non-recurrence cases were definitely smaller than those in 15 recurrence cases (p<0.0001). When a cut-off level of less than 0.4 mV in receiver operating characteristic curves was used, its negative predictive value for non-recurrence of AF was 93% and specificity was 95%.
Conclusions: Circumferential ablation around the PV ostia using the RBC is effective in the treatment of AF even in a single session, and AF recurrence may well be predicted by precisely measuring the amplitude of remaining PV-LA potentials.