Study limitations
Since the current study was cross-sectional, no matching was performed on the subjects; therefore, the heterogeneity in the findings resulted in the use of non-parametric tests. Thus, small number of subjects in each study group could be considered as a limitation of the current study. The overall effect size for one-way ANOVA test ranged from 0.59 to 0.71 and ranged from 0.29 to 0.79 for Kruskal-Wallis test. The effect size indicates that there is a high possibility that the comparison of A velocity and S/D between groups differ if the sample size is increased. It is suggested that further studies include larger samples of patients with any of the conditions. The strength of the current study was the assessment of hepatic venous systolic filling fraction in PHT patients with and without significant RV dysfunction and also remove patients with severe TR and arrhythmia in our study.