5.2 AF substrate extending to the whole left atrium
In this and our previous study,12 whole left atrial
electrophysiological abnormalities such as an extensive mean regional
voltage reduction and a slow left atrial total conduction velocity were
shown to be reliable predictors of AF recurrence.
In addition to the previously reported limited efficacy of LVA
ablation,8,11 these results suggest the important
clinical implication that AF substrate is not always limited to LVAs.
Several substrate-based ablations using different ablation targets have
been proposed. One study reported that the cut-off value of voltage for
the prediction of fibrosis differs between regions,18and others have shown that the use of different voltage criteria
improves the efficacy of LVA ablation.19,20 The
efficacy of ablation targeting fractionated electrograms during sinus
rhythm using an ultra-high resolution mapping system has also been
proposed.21
The management of AF based on therapies for upstream factors which
promote atrial degeneration, such as hypertension, diabetes mellitus,
and heart failure, will likely benefit by considering that the AF
substrate extends across the whole atria rather than being localized to
specific portions.