interventricular septum

The interventricular septum is the muscular partition that separates the two lower chambers of the heart, the ventricles. This septum is crucial for directing blood flow correctly through the heart. Most of the interventricular septum is thick and muscular, but a small fibrous section, known as the membranous septum, is also part of it.12

Defects in this septum, called ventricular septal defects, are congenital openings that can occur in various parts of the septum, most commonly in the membranous portion. These defects can range from small, which may cause no symptoms and close on their own, to large, which can lead to significant blood flow issues between the ventricles. Such defects are a type of congenital heart disease, which can be influenced by genetic or environmental factors.23