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 2 – Proportions of different ostium shapes of the four targeted PVs. D long: PV ostium long diameter; D short : PV ostium short diameter; D corrected : Corrected diameter calculated from PV ostium perimeter PV ostium; CB: cryoballoon; LSPV: left superior pulmonary vein; LIPV: left inferior pulmonary vein; RIPV: right inferior pulmonary vein; RSPV: right superior pulmonary vein. Narrow Triangular Oval Round 5.0 38.3 28.3 28.3 1,7 56.7 18.3 23.3 43.3 53.3 3.3 33.3 63.3 LSPV LIPV RIPV RSPV Locations 0% 20% 40% 60% 80% 100% Percentage Table 2 – PV ostia diameters measured on CT images PV location D long (mm) D short (mm) D corrected (mm) 23-mm CB 28-mm CB p 23-mm CB 28-mm CB p 23-mm CB 28-mm CB p LSPV 20.3 ± 3.0 21.7 ± 2.8 0.06 13.5 ± 2.7 15.2 ± 3.3 .04 17.7 ± 2.7 19.3 ± 2.5 0.02 LIPV 17.4 ± 3.4 17.6 ± 2.1 0.80 11.7 ± 3.3 12.9 ± 2.1 .13 15.3 ± 3.2 15.9 ± 1.9 0.41 RIPV 18.3 ± 3.0 19.6 ± 3.0 0.09 15.6 ± 2.9 17.1 ± 3.0 .054 17.3 ± 2.6 18.8 ± 2.7 0.046 RSPV 21.2 ± 3.0 24.3 ± 3.4 0.001 18.0 ± 3.7 20.4 ± 3.8 .02 20.0 ± 3.0 22.7 ± 3.4 0.01 Total 19.2 ± 3.4 20.8 ± 3.8 0.001 14.6 ± 3.9 16.4 ± 4.1 .001 17.6 ± 3.3 19.1 ± 3.6 0.001 Values are mean ± SD. p: p-value (unpaired Student’s t-test). D long: PV ostium long diameter; D short : PV ostium short diameter; D corrected : Corrected diameter calculated from PV ostium perimeter PV ostium; CB: cryoballoon; LSPV: left superior pulmonary vein; LIPV: left inferior pulmonary vein; RIPV: right inferior pulmonary vein; RSPV: right superior pulmonary vein. CB ablation and cryo kinetics Cryo kinetics can be evaluated from two aspects: freezing temperature and time course. Furnkranz et al. 4 found that BNT could predict acute PVI when using 28-mm CB. Ghosh et al. 5 reported that -30~+15°C BWT was a strong predictor for pulmonary vein reconnection. The current study revealed that BFT, BNT and BWT had significant correlations to each other, which was higher between BNT and the two others. For this reason, we chose BNT as the representative cryo kinetic parameter for analyzing the relationship between PV anatomy and cryo kinetics. A cut-point of < -51°C was selected for logistic regression because BNT < -51°C was invariably associated with PVI, as Ghosh et al. 5 concluded. Relationship between PV Anatomy and Cryo Kinetics The CB ablation basic technique is to achieve cryoenergy‑induced PVI on a condition of appropriate occlusion of PV blood flow and circumferential contact between PV ostia and CB surface, ideally the equatorial region of CB. 15 Sorgente et al. 6 found that PV ostium shape was useful in predicting the degree of occlusion. PV ovality 16 and drainage patterns 9 were reported to have an impact on AF recurrence in some studies. In this study, though a mild to moderate association was found between BNT and D corrected , no association existed either between BNT and PV ostium shape or between BNT and PV drainage pattern. The main reasons for this may be as follows: (1) PV ostia had certain compliance 444