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.