Contribution to the development of the heart. Part 1: normal development

Area of Science:

• Cardiovascular Development
• Embryology
• Cardiac Anatomy

Background:

• Cardiac septa formation is crucial for heart function.
• Understanding septal development aids in diagnosing congenital heart defects.
• Previous research has focused on various aspects of septal development.

Purpose of the Study:

• To elucidate the relationship between external cardiac wall shaping and internal septa formation.
• To identify the precise mechanisms driving the development of fibrous cardiac septa.
• To understand how cardiac looping and deformation influence septal origins.

Main Methods:

• Analysis of cardiac looping and deformation during embryonic development.
• Histological examination of developing cardiac tissue.
• Comparative study of external and internal cardiac wall changes.

Main Results:

• External cardiac wall shape changes precede internal wall changes.
• Cardiac looping causes angulation and deformation of the tubular heart.
• Deformation leads to endocardial/subendocardial tissue growth, forming septal anlagen.
• Septal origins are directly dependent on deformation direction and ventricular growth patterns.
• Septal anlagen form a continuous system of protrusions that fuse.

Conclusions:

• Cardiac septa develop as a consequence of external cardiac wall deformation during looping.
• The process involves a continuous system of tissue protrusions guided by growth patterns.
• This mechanism explains the origin and site of fibrous cardiac septa, including the ventricular septum.