Two-Dimensional Echocardiography Incorrectly Identifies Tricuspid Regurgitation Jet Location Compared to Three-Dimensional Echocardiography in Pre-Operative Assessment of Tricuspid Valve Repair in Hypoplastic Left Heart Syndrome

Background: A recent study using two-dimensional echocardiogram (2DE) reported a predominance of antero-septal commissural regurgitation in patients (70%) undergoing tricuspid valve repair (TVR) in hypoplastic left heart syndrome (HLHS). Three-dimensional echocardiography (3DE) studies on assessment of TV morphology reports a high incidence of error in the identification of TV leaflets in conventional 2DE planes. This study aims to assess the pre-operative 2DE assessment of TR jet location compared to the reference standard of 3DE color datasets in HLHS. Methods: Twenty-five HLHS patients requiring TVR for TR between 2005 and 2015 were assessed using 2DE and 3DE to assess TR grade, 3DE vena contracta (VC) area, TV annulus diameter (indexed to body surface area, iTV) and primary TR jet location. The 2DE observer was blinded to the findings on 3DE. We compared the 2DE findings with 3DE using t-test and Pearson correlation. Surgical notes were reviewed for details of procedures performed. Results: Indexed 2DE iTV was no different to 3DE (61mm/m 2 ± 4 vs. 56mm/m 2 ± 4, p=0.34). 2DE qualitative TR grade correlated with 3DE VC area (r=0.69, p Conclusions: 2DE was accurate in the assessment of the degree of TR and TV annular size, but in most patients incorrectly identified the primary regurgitation location in the antero-septal region instead of other location. This may have implications for planning of the primary surgical procedure in HLHS TV repair based on 2DE findings.