Statistical analysis
Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 21.0. (IBM Corp. Armonk, NY: USA. Released 2012). The normality distribution patterns of variables were evaluated using histograms, probability plots, and analytical methods (Kolmogorov-Smirnov). Variables showed as mean ± standard deviation. Categorical variables were presented as percentages.  Continuous data was compared in gender and age groups using independent T test and One-way ANOVA respectively. Turkey’s HSD was used in post-hoc comparisons. Categorical variables   were compared using the Chi-square test. Pearson correlation test was performed for bivariate correlations. All tests were 2-tailed and the p value was less than 0.05 (p < 0.05) was accepted as significant.
Intra-observer and inter-observer variability was evaluated in 50 randomly selected subjects. Intraclass correlation coefficient with 95% confidence interval and the relative differences (means±SD) were reported overall. The Bland-Altman plot was drawn to obtain better insights into the data quality between two echocardiographers.