3.3 Gap characteristics per segment
Distribution of the gaps and features of the segments with gaps are shown in Figure 3 and Table 3, respectively. Gaps were observed in 26 (8%) of the 330 line segments assessed; 11 in the center roof line segment, 6 in the center floor line segment, 4 in the right roof line segment, 4 in the right floor line segment, and 1 in the left floor segment. The gaps were observed in segments of higher voltage (3.38 ± 1.83 vs. 1.70 ± 1.12 mV, P < 0.0001), with a thicker LA wall (2.52 ± 1.15 vs. 1.42 ± 0.44 mm, P < 0.0001). However, no differences were found in the number of RF points, presence of inter-lesion distance ≥ 6 mm, impedance drop during RF application, or AI. The modified AI was lower in the segments with a gap than in the isolated segments (124 [94–198] vs. 288 [182–463] AU/mV, P < 0.0001).
A 3DCT image and LA bipolar voltage map obtained in a case in which LAPWI was not achieved after numerous high-power RF energy applications are shown in Figure 5. The roof line was found to be incomplete, the wall at the center of the roof line (panel A) was very thick, and the voltage (panel B) was extremely high.