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.