Birth Defect: Atrial Septal Defect
Atrial septal defect (ASD) is a congenital birth defect – that is, it is present at birth – that changes how blood normally flows through the heart.
Structurally, the heart has two sides. The right side receives oxygen-poor blood from the body and pumps it to the lungs to be re-oxygenated. The left side pumps the oxygen-rich blood from the lungs through to the rest of the body. These two sides are separated by a wall or septum. This septum prevents the oxygen-poor blood with the oxygen-rich blood. If this mixing happens from an atrial septal defect, oxygen-rich blood is pumped back to the lungs instead out to the body. Oxygen-poor blood can be pumped out to the body, making both the heart and the lungs work harder.
ASD affects 5 to 10 percent of all children born with a congenital heart defect, and girls twice as much as boys.
Prenatal Development of the Heart
“During the first eight weeks of fetal development, the heart forms. It begins as a hollow tube, then partitions develop within the tube that eventually become the walls that divide the right side of the heart from the left.” (CHB) Every baby is born with a hole between the upper heart chambers to allow blood to flow away from the lungs just before birth. Once born, the hole is no longer needed and eventually closes over the course of several weeks or months. (AHA) This hole can become a problem if it is very large or doesn’t close all the way and is then called an atrial septal defect.
Symptoms and Treatment of ASD
Small openings do not usually produce any symptoms and treatment is not usually necessary. “In children with a large ASD, the main risk is to the blood vessels in the lungs because more blood than normal is being pumped there. Over time … this may cause permanent damage to the lung blood vessels.” (AHA) A large ASD is usually treated with surgery as there is no medication that will cause the hole to close. Surgery may involve placement of an “umbrella” patch through a cardiac catheterization approach, or surgical closing of the hole if it’s in a tricky location that would be hard to reach with the catheter. These surgeries may be done in conjunction with medications to strengthen the heart muscles so it can pump more efficiently.
A baby born with a large ASD may present with the following symptoms:
- Frequent respiratory or lung infections
- Difficulty breathing
- Tiring when feeding
- Shortness of breath during activity
- Skipped heartbeats or a sense of feeling the heartbeat
- A heart murmur (whooshing sound) heard through a stethoscope
- Swelling of legs, feet, or stomach area
Sometimes ASD is not diagnosed until later on in life.
It is not known what causes these defects, neither what precautions pregnant or trying-to-get-pregnant moms should do to prevent the possibility of having a child with a congenital heart defect.
Darlene Oakley is a freelance writer for EmpowHER.com.
What Are Holes in the Heart? National Heart Lung and Blood Institute. Web. Mar 20, 2012.
Atrial Septal defect (ASD). Children’s Hospital Boston. Web. Mar 20, 2012.
Congenital Heart Defects: Facts about Atrial Septal Defect. Centers for Disease Control and Prevention. Web. Mar 20, 2012.
Atrial Septal Defect (ASD). American Heart Association. Web. Mar 20, 2012.