Anatomical relationship between abnormal conduction zone and contact area/low voltage area
Table 2 lists the anatomical relationship between the ACZ and CoAs/LVA. The CoAs were found in all patients. A total of 185 CoAs (average CoA per patient: 6.0±4.1 cm2) were identified. A CoA was found in each of the three representative regions, ascending aorta-anterior LA (3.2±1.8 cm2, 100 of 100 patients, 100%), descending aorta-posterior LA (0.6±1.3 cm2, 26 of 100 patients, 26%), and vertebrae-posterior LA (2.1±2.7 cm2, 58 of 100 patients, 58%). CoA and number of CoA did not differ between the PAF group and the non-PAF group. The overlapping rate of LVA and ACZ showed a tendency to increase in the non-PAF group compared with the PAF group. (Table 2 , mild LVA: 60.6±34.0% vs 42.1±36.2%, P=0.0099; moderate LVA: 41.4±33.3% vs 24.8±30.4%, P=0.0109, severe LVA: 18.9±23.5% vs 10.3±19.9%, P=0.0502). On the other hand, the overlapping rate of CoAs and ACZ did not differ between the PAF (26.5±33.1%) and non-PAF (24.6±21.6%) groups. A larger LA size was associated with a higher overlapping rate of LVA (at each cut-off value) and ACZ. In contrast, the overlapping rate of CoAs and ACZ did not differ among the normal/mildly, moderately, and severely enlarged LA group.