Ventricular septal defect

A wall or other structure that divides one cavity from another. For example, in the heart the muscular septum separates the right side of the heart from the left side.

Abbreviation for ventricular septal defect—one or more holes in the septum, the muscular wall separating the right and left sides of the heart.

Break in the heart muscle that allows blood to escape into the pericardial sac.