Statistical analysis
Categorical variables are described as number (percentage) and were compared with the χ2 or the Fisher’s exact tests, as appropriate. Continuous variables are described as mean ± SD for variables with normal distributions or as median [interquartile range] for variables not normally distributed. The Kolmogorov-Smirnov test was used to assess normality in continuous variables. Comparisons among normal continuous variables were made using Student’s t tests (normal variables) or Mann-Whitney U tests (for variables not normally distributed). Bilateral p values <0.05 were considered statistically significant. For survival analysis (recurrence of atrial arrhythmias), the Kaplan-Meier method was used. Statistical analysis was performed using SPSS Statistics Base version 22.0 package (IBM Inc., Armonk, NY).