Clinical implications
In this study, RAPW pacing could detect the EC that can interrupt PV isolation by antral circumferential ablation, and such an occurrence was higher in patients with a low EAT volume and in relatively younger patients. There has been a dramatic improvement in the efficacy of transmural ablation by using an irrigation catheter, contact force, and the ablation index/lesion size index.21 With these technologies, it is presumed that there are only a few cases in which PV isolation is not achieved because of the inability to achieve circumferential lesions transmurally, and EC may play a more important role in the resistance of PV isolation. Therefore, in relatively younger patients or patients with a small EAT volume, the presence of carina conductivity should be assessed before AF ablation, as early detection of carina conduction may help avoid unnecessary additional antral ablation and collateral damage.