Statistics
IBM SPSS Statistics for Windows, Version 23.0 (IBM Corp., Armonk, NY, USA) was used for statistical analysis. Continuous variable data were presented as the mean ± standard deviation (SD) or as the median. Categorical variables are presented as the percentage. To test for normality of distribution, the Kolmogorov–Smirnov test was used. The Pearson test and Spearman tests were used for correlation analysis to assess the correlation of the RV parameters and PVR with the LA strain parameters. N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels were analyzed as the logarithmic function to provide a normal distribution.
Patients were grouped according to their LVDD grades. For categorical variables, the trend test was performed, and for continuous variables, the one-way ANOVA test or Kruskal–Wallis tests were used to determine the difference among the diastolic dysfunction grades.