Regular AT in patient with LVAs
Patients with LVAs more frequently developed spontaneous or
pacing-induced regular ATs than those without LVAs. In addition, among
patients with LVAs, LVA ablation increased AT incidence. The association
between advanced atrial remodeling and extensive atrial ablation with AT
development is consistent with previous reports. Among these, ATs
developed in 5% to 40% of patients who underwent AF ablation, and the
incidence became higher in patients with longer AF duration or larger
left atrium;11-13 while extensive ablation targeting
complex fractionated electrograms resulted in frequent AT
development.14
The electrophysiological mechanism of the association between LVA
presence and LVA ablation with AT development might be explained as
follows. LVA is reported to include a slow conduction zone and
conduction block,15 and could act as an arrhythmogenic
substrate of reentrant ATs. Although ablation targeting LVAs changes
diseased conduction areas into scar areas with no electrical conduction,
LVA ablation near anatomical obstacles such as the valvular annulus may
unintentionally create an iatrogenic slow conduction isthmus.
Furthermore, linear ablation to isolate LVAs could create conduction
gaps due to incomplete linear lesions.