Atresia of the right atrioventricular orifice with atrioventricular concordance

Area of Science:

• Pediatric Cardiology
• Congenital Heart Disease
• Cardiac Morphology

Background:

• Tricuspid atresia is a complex congenital heart defect.
• Accurate classification is crucial for understanding disease and guiding treatment.
• Previous classifications may not fully encompass all morphological variations.

Purpose of the Study:

• To investigate the morphological and histological features of specific congenital heart specimens.
• To re-evaluate the classification of hearts with atresia of the right atrioventricular orifice.
• To differentiate these cases from classical tricuspid atresia.

Main Methods:

• Detailed morphological examination of three heart specimens.
• Histological analysis of cardiac tissue, focusing on conducting system distribution.
• Comparison of findings with established criteria for tricuspid atresia and univentricular hearts.

Main Results:

• Three hearts exhibited a fibrous membrane between the right atrium and a hypoplastic right ventricle.
• These hearts showed recognizable inlet, trabecular, and infundibular components.
• Conducting tissue distribution was consistent with concordant atrioventricular connections, differing from classical tricuspid atresia.

Conclusions:

• The findings support classifying the majority of right atrioventricular orifice atresia cases as a form of the univentricular heart.
• This reclassification offers a more accurate understanding of these cardiac anomalies.
• Distinguishing these from classical tricuspid atresia is essential for clinical management.