SPSS software is used for statistical analysis. All continuous variables are presented as mean ± standard deviation. Comparison of clinical and echocardiographic characteristics is performed by chi-square analysis for categorical variables and by Student t test for echocardiography and other continuous variables. A p value < 0.05 is considered significant. Patients will be subdivided to four quartiles according to left atrial distensibility. Unadjusted survival curves are produced using the Kaplan-Meier method. The log-rank test is used to compare survival curves. Adjusted survival curves are constructed using variables entered into the Cox model set to their mean values in the total population. The hazard ratio of low left atrial distensibility will be assessed by comparing quartile to quartile.