Atrioventricular septal defect with coexisting tricuspid atresia

Area of Science:

• Pediatric Cardiology
• Congenital Heart Disease
• Developmental Biology

Background:

• Atrioventricular septal defects (AVSD) are complex congenital heart conditions.
• Understanding variations in AVSD is crucial for diagnosis and management.
• Rare anatomical presentations require detailed investigation.

Observation:

• Two infants presented with AVSD and double inlet atrioventricular connection, featuring a patent left-sided valve orifice and an imperforate right-sided valve component.
• A third infant had AVSD with an imperforate Ebstein's malformation.
• These conditions collectively produced the hemodynamic effect of tricuspid atresia.

Findings:

• The observed cardiac anomalies in infants share similarities with findings in trisomy 16 mouse models, specifically deficient atrioventricular septation with a common atrioventricular junction connected solely to the left ventricle.
• This specific anatomical arrangement, though rare, has significant hemodynamic consequences mirroring tricuspid atresia.

Implications:

• The study highlights rare but critical congenital heart malformations with significant theoretical implications for understanding cardiac development.
• These findings underscore the importance of recognizing atypical presentations of AVSD and their association with conditions like tricuspid atresia.
• Comparative analysis with animal models provides valuable insights into the genetic and developmental pathways of complex congenital heart defects.