Exploring three-dimensional right ventricular shape and function in Tetralogy of Fallot patients

Tetralogy of Fallot (ToF) accounts for approximately 7-10% of all congenital heart disease and is frequently complicated by right ventricular (RV) dysfunction. Three-dimensional echocardiography (3DE) offers more accurate assessment of RV volume and function, facilitating advanced evaluation of RV geometry. Building on this, a custom software tool was developed to quantify RV shape and function. This study aimed to assess the differences of 3DE derived RV shape and function parameters in ToF and healthy controls. 3DE RV datasets were acquired in 50 ToF and 50 healthy controls. RVs were segmented using commercially available software (TomTec) and further processed with custom software to quantify mean curvature (MC), area strain (AS), and longitudinal strain (LS). Measurements were performed globally and regionally across predefined RV segments. Curvature analysis identified the posterior boundary (253% [227-265] vs. 283% [260-301] vs. 294% [264-329]; for volume overload, absent overload and healthy controls, respectively; p < 0.001) and apex (464% [419-529] vs. 501% [467-541] vs. 554 [486-619]; for volume overload, absent overload and healthy controls, respectively; p < 0.001) as key regions driving RV remodeling in ToF. Septal flattening was observed in ToF with decreased concavity of the SB (p = 0.007). Global RV AS was significantly reduced in ToF (p < 0.05), with the largest impairment observed at the apex (-16% [-21;-12] vs. -14% [-17;-6] vs. -38% [-42;-28]; for volume overload, absent overload and healthy controls, respectively; p < 0.001). This in-house developed software enables comprehensive RV morphology and deformation analysis from standard 3DE imaging. Curvature analysis provides a novel and sensitive measure of RV remodeling, while AS and LS offer detailed insight into regional RV dysfunction. Improved characterization of RV remodeling may support clinical decision-making.