Exploring the Interatrial Septum: Functionality, Mobility, and Clinical Relevance

Teaching Cases & More

Background

The interatrial septum (IAS) is a wall of tissue that separates the two upper chambers of the heart, the right and left atrium. During fetal development, the lungs are not yet fully functional, so a hole in the IAS, the foramen ovale, allows oxygen-rich blood from the placenta to bypass the lungs. This blood is shunted directly from the right atrium to the left atrium, avoiding the pulmonary circulation and entering systemic circulation. After birth, as the pressure in the left side of the heart rises, the foramen ovale closes, enabling the baby to start using its lungs for oxygen.

Echocardiography is used to assess the movement of the interatrial septum (IAS) and provides key insights into the hemodynamic changes occurring within the heart. In this lesson, we will guide you through how to visualize the IAS, the different types of movements you may observe, and present case examples to enhance your understanding.