The significance of pulmonary veins isolation radiofrequency time and the evolution of left atrium volume on a twelve-year observational follow-up of paroxysmal atrial fibrillation patients

Atrial fibrillation recurrence post pulmonary vein isolation: the complex secrets of left atrial geometry

Buffle et al are to be congratulated for shedding more light on the electrophysiologic links regarding atrial fibrillation recurrence post radiofrequency catheter ablation. The different approaches of left atrium volume and left atrium diameter assessment employed in this study, is a limitation that should not go unnoticed, since angiographically calculated left atrium volume overestimates volume as compared to 3D echo measurements. Further, the timing of change has been reported to have prognostic significance; namely left atrium diameter reduction within the 3 month blanking period has been reported to independently predict prolonged arrhythmia free survival. Hence, we firmly believe that future studies should examine any potential correlations between left atrium diameter and recurrence mechanisms.

Changes in LA volume and diameter correlate with mechanisms of recurrence after paroxysmal AF ablation

Papathanasiou et al point out that the two different methods of LA volume and diameter measurement in our recent publication could limit the significance of the correlations we reported with PV reconnection and non-PV foci as mechanisms of post AF ablation recurrence. While we acknowledge the lack of statistically significant correlations of smaller echo derived LA diameter with PV reconnection or of a larger angiographic LA volume with non-PV foci, the congruent confidence intervals of this correlation suggest a statistical trend. Non-uniform LA dimensional changes as an expression of structural remodelling may also be a possible explanation. Published data indicates that angiographic LA volumes consistently exhibit a positive bias compared to echocardiographic volumes but do provide intra-procedural measurements better correlating with gold standard techniques like CT or MRI. Finally we agree with Papathanasiou et al that dynamic changes in LA dimensions likely correlate with early and late mechanisms of recurrence and merit prospective studies.