The role of first-trimester single arterial vessel sign instead of a V-sign at the level of the three-vessel and tracheal view in screening for congenital heart diseases

Introduction
Despite efforts from dedicated societies, prenatal detection rates (DRs) of congenital heart diseases (CHDs) remain unsatisfactory. Early cardiac scan is believed to play an important role in selecting fetuses for further assessment and to improve the DRs. The aims of the study were to compare first-trimester cardiac parameters and follow-up fetal, postnatal echocardiography and autopsy findings in fetuses presenting the single arterial vessel with fetuses presenting the “V-sign” at the level of the 3 vessels and trachea view in colour mapping (3VTVc), and to measure screening performance of the single arterial vessel in 3VTV for D-TGA and D-TGA+VSD, all CHDs, and ductal-dependent (DD) CHDs.

Material and methods
This study was a prospective observational analysis that covered 2338 pregnancy referrals. Study protocol included an early fetal echocardiography approach to the 4-chamber view in colour mapping and 3VTVc.

Results
Among single arterial vessel fetuses 2 normal hearts, 66 CHDs, including 42 DD lesions, were identified; and among “V-sign” fetuses, 1913 normal hearts, 42 CHDs, including 2 DD lesions. The single arterial vessel sign was highly sensitive (93.3%) and specific (97.3%) for D-TGA/D-TGA+VSD at the time of the early cardiac scan. Moreover, the single arterial vessel in 3VTV was highly sensitive (95.8%) and specific (98.8%) for other ductal-dependent CHDs.

Conclusions
Differentiation between the single arterial vessel sign in 3VTV and the “V-sign” is replicable and safe due to the short exposure time for colour mapping needed to obtain satisfactory images. This would help establish their use as another strong prenatal predictor of important congenital heart disease, D-TGA, and other DD-lesions.