Biatrial tachycardia
A previous study reported that biatrial tachycardia is more likely to
develop in patients with an obstacle to conduction in the left atrial
septum.16,17 In this study, all cases of biatrial
tachycardia developed in patients with broad anterior-septal LVA
ablation. In contrast, biatrial tachycardia was not observed in patients
without anterior-septal ablation, even in patients with broad LVA at the
anterior-septal lesion. This suggests that conduction block by ablation
scar rather than conduction slowing due to diseased myocardium provides
the substrate for biatrial tachycardia.
An ablation target of biatrial tachycardia is the left or right atrial
conduction breakout points.14 However, it is sometimes
difficult to eliminate reentrant circuits, possibly due to broad
inter-atrial conduction. In this study, ablation did not eliminate
biatrial tachycardia in 2 of 6
patients
(Supplementary Table). Lateral mitral isthmus ablation can be an
alternative ablation target of biatrial tachycardia,15but requires careful consideration of electrical conduction disturbance
to the left atrial appendage.