Straddling right atrioventricular valves in atrioventricular discordance

Area of Science:

• Cardiology
• Congenital Heart Disease
• Cardiac Morphology

Background:

• Congenital heart disease presents diverse anatomical challenges.
• Understanding atrioventricular valve abnormalities is crucial for diagnosis and treatment.

Observation:

• Four hearts exhibited a right atrioventricular valve straddling the interventricular septum.
• The valve committed 20-45% of flow to the morphologically right ventricle.
• Ventriculoarterial connections varied, including discordant, double outlet, and single outlet with pulmonary atresia.

Findings:

• Pulmonary stenosis or atresia was noted in all cases.
• Conduction system analysis revealed an anterior atrioventricular node and penetrating bundle, with lateral connections.
• A unique conduction tissue sling was observed in one case.

Implications:

• These anatomical variations necessitate tailored surgical approaches.
• Detailed understanding of conduction pathways is vital for managing complex congenital heart defects.
• Further research can refine diagnostic and therapeutic strategies for these rare conditions.