Understanding of cardiac structure has been improved by 3D cardiac echocardiography. The anatomy and geometry of the mitral valve annulus (MVA) has been previously described with advanced imaging techniques, allowing for a better comprehension of valve dysfunction and providing significant information for the surgical repair.

To apply transthoracic 3D echocardiography (3DTTE) for quantitative and qualitative assessment and comparison of the pathologic MVA in congenital cardiopathies (CC) of the valve with a normal group.

Patients with repaired atrioventricular septal defect (AVSD) attending consultation were prospectively included and matched with a control group of healthy children by sex, age and body surface area (BSA). 3DTTE full volume and 3D zoom acquisitions were performed on a Philips EPIQ7. The 3D shape of the annuli was reconstructed and analysed with TOMTEC™ 4D MV-ASSESSMENT© (Fig. 1). The assessed and compared parameters were annular area (2D & 3D), circumference, high-low distances (height), anterolateral-posterolateral (ALPM), and anteroposterior (AP) axes, non-planar angle (NPA), sphericity index, angle between the aortic annulus and AP axe (AAoAPangle). All measurements were indexed by BSA.

A total of 18 participants were recruited. Both groups were comparable in age (10.67±3.45 years) and BSA (1.13±0.27 m²). All acquisitions could be analysed with need of minimal editing of the annulus after automated detection, leaflets couldn’t be analysed in the AVSD group. Significative differences between both groups were found in the NPA with an increase in the nonplanarity for the patients with a repaired AVSD (144.5 vs. 132.9; P˂0.01) and a more circular shape represented by a higher sphericity index (0.99 vs. 0,85; P=0.01). No difference was found in indexed height, area and diameters were similar between both groups.

The specific and exclusive shape of the MVA in patients with repaired AVSD was revealed in the patients studied, resulting in a loss of the saddle shape structure. Those results could help in the comprehension of anatomic changes of the mitral valve annulus occurring after AVSD surgery.