187 Is the right ventricle truly dilated? Comparing 2d and 3d echocardiography with cardiac MRI

Introduction Two dimensional echocardiographic (2DE) assessment of the right ventricle (RV) has limitations. Three-dimensional echocardiographic (3DE) assessment of RV volumes has been validated against cardiac magnetic resonance imaging (CMRI). We hypothesised the addition of 3DE would improve assessment of RV size and be comparable to CMRI in a public hospital setting. Method Consecutive patients planned for inpatient CMRI for any indication underwent 3DE on the same day. CMRI, 3DE and 2DE data were analyzed. Results 16 patients were included. 3DE and CMRI RV end systolic and end diastolic volumes were highly correlated (r=0.95 and 0.90 respectively). Mean RV end diastolic and end systolic volume was significantly lower on 3DE compared to CMRI; (175 ml +/-54.2 vs 193.69 ml +/- 59.9, p= 0.01) and (92.56 +/- 41.26 vs 106.06 +/- 49.93, p = 0.015) respectively. There was no significant difference between 3DE and CMRI RV ejection fraction (48.31% +/- 10.54 vs 45.75% +/- 11.22). Dilated RV on 2DE was seen in n=9 (56%). Of these, n=7 (78%) were reclassified to normal RV size based on 3DE and CMRI. The addition of 3DE to 2DE increased the specificity, as compared to CMRI, of detecting a dilated RV from 50% to 100%. Conclusion : These findings show 3DE RV volumes are highly correlated and consistently smaller than CMRI RV volumes. The addition of 3DE to 2DE improves the specificity of detecting a dilated RV. All patients with RV dilatation on 3DE were found to have RV dilatation on CMRI, a specificity of 100%. Conflict of Interest Nil