Population characteristics of cats enrolled in the echocardiographic study.

Normally distributed data are represented mean (±standard deviation) and compared using a one-way ANOVA. Non-normally distributed data are represented median (range) and compared using a Kruskal-Wallis test. Categorical variables are represented as percentages and compared using a Chi squared test.正态分布数据以均值±标准差（standard deviation）表示，组间比较采用单因素方差分析（one-way ANOVA）；非正态分布数据以中位数（范围）表示，组间比较采用Kruskal-Wallis检验（Kruskal-Wallis test）；分类变量以百分比形式呈现，组间比较采用卡方检验（Chi squared test）。