What is a ventricle? The single-ventricle trap

Area of Science:

• Cardiology
• Anatomy
• Congenital Heart Disease

Background:

• The definition of cardiac ventricles is traditionally based on atrioventricular (AV) connections.
• Existing definitions, particularly for single ventricle, are considered unsatisfactory and scientifically inaccurate.
• This leads to confusion in diagnosing and describing congenital heart disease.

Purpose of the Study:

• To advocate for a redefinition of cardiac ventricles based on myocardial morphology.
• To highlight the inadequacy of current definitions that rely on AV connections.
• To promote a return to a purely morphological approach in cardiac anatomy and congenital heart disease terminology.

Main Methods:

• Critical analysis of existing definitions of cardiac ventricles and single ventricles.
• Review of established anatomical and morphological principles in cardiology.
• Comparison of morphological characteristics versus AV connections for chamber identification.

Main Results:

• Myocardial morphology, not AV connections, definitively determines if a chamber is a ventricle.
• The morphologically right and left ventricles have well-established anatomic characteristics.
• The classic definition of a single ventricle is fundamentally flawed and violates morphological diagnostic principles.

Conclusions:

• Redefining ventricles based on AV connections is inappropriate and scientifically unsound.
• Terminology like "primitive ventricle" or "main chamber" should be abandoned in favor of precise morphological descriptions.
• Unadorned morphological anatomy is essential for clarity, simplicity, and accuracy in congenital heart disease classification and understanding.