Biatrial tachycardia
Six of 31 regular ATs had reentrant circuits which included both the
right and left atria (biatrial tachycardia). Notably, all 6 of these
biatrial tachycardias were observed in group B, and no patients in other
groups developed biatrial tachycardia. The reentrant circuit consisted
of the mitral annulus and right atrial septum in all biatrial
tachycardias.
Clinical background, ablation procedures, and ablation outcomes of each
patient with biatrial tachycardia are shown in the Supplementary Table.
Comparisons of anatomical and electrophysiological properties between
patients with and without biatrial AT in group B are shown in Table 4.
Patients with biatrial tachycardia had larger anterior and/or septal
LVAs, and underwent anterior and/or septal linear ablations.
Ablation targeting breakout points into the left and/or right atria
successfully eliminated biatrial tachycardia in 4 of 6 (66.7%)
patients. In the remaining 2 patients with failed ablation at left and
right atrial breakout points, lateral mitral isthmus linear ablation was
performed in 1 patient, but block line could not be achieved. The other
patient had conduction disturbance across the septal to anterior region
due to an ablation scar, and did not undergo lateral mitral isthmus
ablation in consideration of electrical isolation of the left atrial
appendage.
Successful AT elimination rate was significantly lower for biatrial
tachycardias than for the other ATs (4 of 6 [66.7%] vs. 25 of 25
[100%] ATs, p = 0.010).