Echocardiographic Variables:
Table 2 shows the echocardiographic variables of the subgroups. The right ventricular systolic pressure was 30.97 +/- 9.27, 36.72 +/- 14.50, and 48.12 +/- 13.92, respectively, in normal, moderately reduced, and severely reduced EF patients (p<0.0001). Reproducibility of inter-observer variabilities was calculated for all the four variables, S’, TAPSE, RV FAC, and lateral RV free wall strain. There was a significant difference in the parameters assessed for RV systolic function (Table 2) . There was a linear association with the MRI reference parameter of RVEF with RVEF <45% and RVEF < 30% for all the variables, with strain having the most significant association (Figure 2 and Figure 3 ). Other parameters like LV mass index, LV end-diastolic mass, and LV end-diastolic mass indices also significantly differed among the groups. ROC curves with cutoffs of RVEF<45%, and RVEF ≤ 30% are shown in Figure 4 estimating the accuracy of echocardiographic parameters to predict RV function. The echocardiographic parameter that most accurately assessed the RV systolic function was RV lateral free wall strain and the area under the curve (AUC) for ROC was 0.69 (95% CI 0.63 – 0.75) and 0.78 (95% CI 0.70 – 0.88) in the groups B and C respectively (Table 3) . RV FAC % ranked second in the accuracy of predicting RV systolic function among the TTE parameters in both groups.