Anatomical-embryological correlates in atrioventricular septal defect

Area of Science:

• Embryology
• Cardiovascular Science
• Developmental Biology

Background:

• Recent embryological studies suggest the ventricular septum has a multifocal origin.
• Existing classifications of atrioventricular septal defects (AVSD) lack convincing correlation with embryology.
• Morphology of congenital heart defects often correlates with embryological development.

Purpose of the Study:

• To review the anatomy and ontogeny of atrioventricular septal defects.
• To present a novel hypothesis for the developmental origins of AVSD.
• To clarify the relationship between AVSD and ventricular septation.

Main Methods:

• Review of existing embryological data and cardiac malformation morphology.
• Analysis of the anatomical features of atrioventricular septal defects.
• Formulation of a developmental hypothesis for AVSD based on embryological principles.

Main Results:

• Atrioventricular septal defects correlate with observations on ventricular septation.
• The primary malformation in AVSD is located in the ventricular septum, not the atrial septum.
• A spectrum of anomalies exists, from inlet septal defects to common atrioventricular orifices, often associated with other cardiac malformations.

Conclusions:

• The development of atrioventricular septal defects is linked to the multifocal origin of the ventricular septum.
• A new hypothesis clarifies the embryological basis of AVSD.
• Understanding the embryology provides a framework for classifying the spectrum of related cardiac malformations.