Tricuspid valve (TV) assessment is essential in various congenital heart diseases. 2D echo remains the cornerstone of TV annulus (TVA) measure but is limited by its complex shape. We investigated in children, the feasibility of 3D-Transthoracic echo (TTE) in TVA assessment compared with 2D.

Methods .– Diameters of TVA were performed on three 2D sectional views [parasternal short axis (PSA), apical four chambers (A4C), parasternal right ventricular inflow (PSRVI)]. “En face view” of the TV was obtained with real time zoom 3D in A4C (3D-matrix array X7-2, X5-1, X3-1 probes, iE33 Philips ^® ). Off-line measures of maximal ( ^m TVAd) and minimal ( _m TVAd) diameters were performed using multiplanar reconstruction on Qlab ^® Software. An asymmetric ratio was calculated ( ^m TVAd/ _m TVAd).

Results .– Sixty-four children (7.1 ± 5.4 years; weight 2.2–82 kgs) with (42.2%) and without (57.8%) cardiopathy were prospectively included. Feasibility of 3D TV dataset was possible in all cases. Quality was estimated to be fairly good in 69.8% of cases. Leaflets visualization was possible in all unless in three children (95.2%) and was better when 3D data set quality was good ( P < 0.0001) ^m TVAd was from septal to lateral axis. Pearson Correlations were good between ^m TVAd, _m TVAd and 2D sectional diameters ( r ≥ 0.8 in all cases, P < 0.0001). TVA was asymmetric with a ratio > 1.2 in 43 children (67.2%) without significant difference according to the cardiopathy. Difference between ^m TVAd and _m TVAd was 10.3 ± 13.2 mm/m ² ( P < 0.0001). PSA was higher than ^m TVAd ( P = 0.001) whereas ^m TVAd was higher than PRSVI ( P < 0.0001) and closed to A4C although superior ( P = 0.03) ^m TVAd was higher than A4C when ^m TVAd < 25 mm and the contrary was seen for ^m TVAd > 25 mm.

Conclusion .– Feasibility of 3D imaging of the tricuspid valve is good in children with or without cardiopathy. According to 3D TVA diameters, the 2D A4C seems to be the most reliable sectional view, while the 2D-PSRVI underestimates the TAD. Conversely, the 2D PSA seems to overestimate TVA compared to 3D measures.