Anatomical relationship between abnormal conduction zone and
contact area/low voltage area
All patients underwent ECG-gated 64-slice multidetector CT (SOMATOM
Definition Edge; Siemens) with slice acquisition thickness set at 0.5
mm. The CoAs (ascending
aorta-anterior LA, descending aorta-posterior LA, and
vertebrae-posterior LA) were assessed using CT. The anatomical distance
between those structures and the LA was calculated. CoA was defined as
the distance between any external structures and LA was within 3
mm.13 Subsequently, we traced the CoAs inside the LA
on each 2-mm CT slice, and three particular areas were created on the
3-D mapping system (Figure 2 ). The CoA size was manually
measured on each segment. The anatomical relationship between the ACZ
and CoAs/LVA at each cut-off value was analyzed (Figure 2 ). The
overlapping rate of the ACZ and CoAs/LVA was assessed for each patient
(Figure 1, 2 ).