The Anatomy of the Atrioventricular Node.

Area of Science:

• Cardiovascular Anatomy
• Cardiac Electrophysiology

Background:

• The precise anatomical arrangement of the atrioventricular node is complex and exhibits significant interspecies variability.
• Previous misunderstandings stem from a lack of detailed knowledge regarding the node's location relative to septal structures.

Purpose of the Study:

• To elucidate the anatomical intricacies of the atrioventricular node.
• To clarify its position within the heart's conduction system and its developmental origins.

Main Methods:

• Comparative analysis of gross and virtual dissections.
• Examination of serial sections from human and animal hearts.
• Integration of developmental biology insights.

Main Results:

• The atrioventricular node resides in the inferior pyramidal space, forming the non-branching component of the conduction axis.
• It receives contributions from the tricuspid and mitral vestibules and the atrial septum.
• Developmental insights explain persisting nodoventricular connections.

Conclusions:

• The study clarifies the atrioventricular node's complex anatomy and its role in cardiac conduction.
• Understanding its anatomical variations is crucial for interpreting cardiac arrhythmias like atrioventricular re-entry tachycardia.
• Significant species-specific variations underscore the importance of comparative anatomical studies.