A 2D finite element model of the interventricular septum under normal and abnormal loading

Area of Science:

• Cardiovascular Mechanics
• Biomedical Engineering
• Cardiac Physiology

Background:

• The interventricular septum separates heart ventricles but its structural behavior under abnormal loading is poorly understood.
• Previous models often ignored right ventricular pressure effects on the septum.
• Abnormal loading can cause the septum to flatten or invert, likened to a 'flapping sail'.

Purpose of the Study:

• To investigate the structural behavior of the interventricular septum during diastole under normal versus abnormal loading conditions.
• To analyze the distinct stress patterns within the septum under different loading scenarios.
• To explore the implications of these stress patterns for understanding pathological conditions.

Main Methods:

• A 2-D plane stress Finite Element (FE) model of the interventricular septum was employed.
• The model simulated diastolic behavior under both normal and abnormal loading conditions.
• Biaxial stress patterns were analyzed to compare structural responses.

Main Results:

• Under normal loading, the septum exhibits low circumferential tension and radial compression, similar to a thick-walled cylinder.
• Under abnormal loading, the septum behaves arch-like, experiencing high compressive stresses circumferentially and radially.
• Distinctly disparate biaxial stress patterns were observed between normal and abnormal loading.

Conclusions:

• Right ventricular pressures induce bending effects in the heart wall.
• High compressive stresses in the septum under abnormal loading may explain previously unexplained pathological conditions.
• Understanding septum mechanics is crucial for diagnosing and treating cardiac abnormalities.