What are Holes in the Heart? What are Holes in the Heart?
National Heart Lung and Blood Institute

A hole in the heart (also called an atrial septal defect (ASD) or ventricular septal defect (VSD)) is a type of simple congenital (kon-JEN-i-tal) heart defect. This is a problem with the heart’s structure that’s present at birth. Congenital heart defects change the normal flow of blood through the heart.

Your heart has two sides, separated by an inner wall called the septum. With each heartbeat, the right side of the heart receives oxygen-poor blood from the body and pumps it to the lungs. The left side of the heart receives oxygen-rich blood from the lungs and pumps it to the body. The septum prevents mixing of blood between the two sides of the heart.

Some babies are born with a hole in the upper or lower septum. A hole in the septum between the heart’s upper two chambers (the atria, pronounced AY-tree-uh) is an ASD. A hole in the septum between the heart’s lower two chambers (the ventricles, pronounced VEN-trih-kuls) is a VSD.

A hole in the septum can allow blood to pass from the left side of the heart to the right side. This means that oxygen-rich blood can mix with oxygen-poor blood, causing the oxygen-rich blood to be pumped to the lungs a second time.

Over the past few decades, the diagnosis and treatment of ASDs and VSDs have greatly improved. As a result, a child with a simple heart defect can grow to adulthood and live a normal, active, and productive life because his or her heart defect closes on its own or has been repaired.