Malalignment of the septum primum with abnormally positioned left atrial appendage: unusual combination in a Shone's...

Area of Science:

• Congenital Cardiology
• Pediatric Cardiac Surgery
• Fetal Cardiac Development

Background:

• Shone's anomaly is a complex congenital heart disease characterized by left-sided obstructive lesions.
• This case presents a rare variant of Shone's anomaly with unique anatomical features.

Observation:

• The patient exhibited a small left ventricle, mitral valve hypoplasia, bicuspid aortic valve, and coarctation of the aorta.
• An unusual arrangement of atrial appendages was noted, with the left atrial appendage positioned behind the great arteries.
• Partially anomalous pulmonary venous drainage was attributed to a deviated atrial septum.

Findings:

• The left atrial appendage was accessible from the right atrium during catheterization, despite its posterior positioning.
• The right atrial appendage demonstrated normal origin and orientation.
• The anatomical findings suggest significant disruption in normal septation and chamber development.

Implications:

• Understanding this variant is crucial for accurate diagnosis and surgical planning in complex congenital heart disease.
• The described anatomy provides insights into the potential mechanisms and developmental pathways of left-sided obstructive lesions.
• Further review of fetal cardiac development is warranted to elucidate the etiology of such complex presentations.