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.