2.4 Statistical analysis
Statistical analysis of all data was performed using SPSS 25. 0. The
continuous variables were tested for normality using the Shapiro-Wilks
test. When the continuous variables were conformed to normal
distributions, they were expressed as mean±SD, and the date with skewed
distributions were expressed as medians with 25% and 75% interquartile
ranges. Categorical variables were expressed as numbers with
percentages. The continuous variables conforming to normal distribution
between three groups were compared by F-test or Welch’s test. When at
least one of three groups of continuous variables conforms to skewed
distribution, the kruskal-Wallis test was used. Then, we performed
multiple comparisons between groups. Categorical variables between three
groups were compared by Chi-square test. Pearson and Spearman
Correlation Coefficient were used to determine the correlation between
EAT thickness and LAD, as well as the correlation between EAT thickness
and left atrial phasic function in patients with AF. Intra-class
correlation coefficient (ICC) was used to test the reproducibility of
measurement of EAT thickness and left atrial phasic function parameters
within and between operators. For all tests, a p<0. 05 was
defined as statistically significant.