ABC | Volume 110, Nº5, May 2018

Original Article Chen et al PV anatomy and cryo kinetics Arq Bras Cardiol. 2018; 110(5):440-448 Figure 1 – PV ostium shapes category and PV drainage patterns.A) PV ostia depicted semi-automatically using CartoMerge software. Four shapes of PV ostium; B) Type I (round); C) Type II (oval); D) Type III (triangular); and E) Type IV (narrow). Five patterns of PV drainage; F) Four PVs drains into LA in a typical pattern; G) Left superior and inferior PVs drains into LA both in a pattern of with common trunk; H) Left superior and inferior PVs drains into LA both in a pattern of with common antrum; I) Right inferior PV drains into LA in a pattern of with ostial branch; J) Right superior and inferior PVs drains in LA with supernumerary vein (middle vein). association between two variables based on its distributions. Logistic regression was performed to investigate the predictive values of PV anatomic parameters for cryo kinetic effect. Variables with a p value < 0.10 in univariate analysis were included into the multivariate analysis, which was performed using an enter approach with criteria of p < 0.05 for inclusion in and p > 0.05 for exclusion from the model. A two-sided p < 0.05 was considered statistically significant. All statistical analysis were performed using IBM SPSS statistical software (Version 20.0, SPSS). Results Study population and procedural data The study population baseline characteristics and ablation procedure parameters are presented in Table 1.Compared with 28-mm CB only, the acute PVI rates were not significantly different when ablation was using 23-mmCB only either on PV level (92.5% vs. 96.9%, p = 0.16) or on patient level (79.4% vs. 91.7%, p = 0.28). No significant difference was found in total complication rate between 28- or 23-mm CBs (8.8% vs. 4.2%, p = 0.64). One case of PN palsy, taken as major, was detected during freezing in a right inferior PV using a 28-mm CB and did not recover until discharge. One case of pericardial and pleural effusion, two cases of left groin hematomas were all resolved within one month post-procedure. Anatomy data The pre-analysis on reproducibility revealed that inter‑observer ICC of D long , D short and D corrected was 0.93, 0.95 and 0.96 (all p < 0.001), and intra-observer ICC of three measured diameters was 0.90, 0.96 and 0.93 respectively (all p < 0.001). Diameters of 240 PVs measured on CT images were listed in Table 2. Compared with ablation using 23-mm CBs, ratio of D corrected and CB diameter was much smaller when frozen using 28-mm CBs (0.76 ± 0.14 vs. 0.68 ± 0.13, p < 0.001). Linear correlation analysis showed that D corrected was strongly correlated with D long (correlation coefficient: 0.93, p < 0.001) and D short (correlation coefficient: 0.90, p < 0.001), while the latter two were moderately correlated with each other (correlation coefficient: 0.74, p < 0.001). Values of D short / D long were between 0.38 and 1.00. Proportions of different ostium shapes and drainage patterns of four targeted PVs are presented in Figure 2 and Table 3. Cryo kinetics 238 targeted PVs were frozen 606 times. Of which, 102 PVs were frozen 254 times using 23-mm CB, and 141 PVs 352 times using 28-mm CB. Compared with 28 mm CBs, BFT was shorter and BNT was lower when using 23-mm CBs in all PV locations (all p < 0.001), while BWT was shorter only in superior PVs (see Table 4). 442