Background .– Bicuspid aortic valve (BAV) is the most common congenital heart defect. Children with BAV are more likely to have valve dysfunction and to require intervention during childhood. According to the subtype of BAV, prognosis and treatment may be different.

Objective .– To assess the accuracy of 3D echocardiography (3DE) in order to diagnose BAV and to depict accurately the leaflets morphology.

Materials and methods .– Seventy-two consecutive children with suspicion of BAV were included in a prospective monocentric study. 2DE and 3DE views were recorded by the same investigator and analysed separately by two confirmed paediatric cardiologists in order to assess BAV. We compared 2DE and 3DE for the description of the spatial position of cusps and raphes. The association with aortic aneurysms, aortic coarctation, aortic insufficiency or stenosis and other cardiac malformation were also reported.

Results .– The median age was 5 years. Using 3DE, BAV was not found in 11,1%[CI 95%, 5,0–20,7] of suspected patients on 2DE. Only 44,4% of uncertain BAV on 2DE was confirmed by 3DE. For 34,4%[CI 95%, 22,9–47,3] of patients, 3DE allowed a better visualisation of leaflets morphology leading to a reclassification of the BAV. The correlation between 2DE and 3DE was moderate (κ = 0.57) concerning the classification of BAV according to the raphe localisation. Mean time 3DE acquisition is 2,3 minutes; interobserver variability in 3DE is almost null (κ = 0.93).

Conclusion .– 3DE is simple, rapid and reliable to diagnose and describe precisely BAV in children. This may be particularly helpful to precise the prognosis or to guide the surgeon.