Factors associated with GH
The baseline characteristics or ablation results in each group are shown in Tables 1 and 2 . There were no significant differences in the nadir temperature of the cryballoon during ablation between the GH+ and GH– groups. Although the percentage of patients in whom LET decreased below 15°C was higher in the GH+ group, especially during CBA of the LA roof, no significant between-group differences were observed. Among these patients, nadir LET did not significantly differ between GH+ and GH–. LA roof height and the distance between the LA roof and esophagus were significantly lower among patients in whom the LET reached 15°C during CBA of the LA roof (Figure 3B and C ). Univariate and multivariate analyses indicated that LA roof height was a reliable predictor of GH (Table 3 ). A receiver-operating characteristic curve for LA roof height had an area under the curve of 0.90 (confidence interval: 0.81–0.99, Figure 5 ). The cutoff LA roof height for predicting GH after additional CBA of the LA roof was 6.1 mm, with a sensitivity of 85.0% and specificity of 83.0%.