What is interrupted aortic arch (IAA)?

Interrupted aortic arch (IAA) is a rare condition in which the aorta—the large blood vessel arising from the heart that carries blood to the rest of the body—is incomplete, or interrupted.

The human heart has four chambers: the left atrium and right atrium (plural: atria) at the top, and the left and right ventricles (pumping chambers) on the bottom. Blood circulates through the atria and the ventricles to and from the rest of the body.

In a normal heart, blood that has picked up oxygen from the lungs comes into the left atrium. From there, it goes into the left ventricle. The left ventricle pumps this oxygenated blood through the aorta to the rest of the body.

The normal shape of the aorta is an arch or curve; in the case of an interrupted aortic arch, a part of the aorta is missing and the aorta is incomplete. This means that the heart cannot send blood through the aorta. This is a life-threatening situation; if blood does not get to any part of the body, the patient can go into shock and may die.

How common is interrupted aortic arch?

IAA is an extremely rare condition; it occurs in 2 of every 100,000 births.

What is the cause of interrupted aortic arch?

IAA is a genetic, or inherited disease. Specifically, a section of a chromosome that affects the heart’s anatomy is missing. This is responsible for changing the normal shape of the heart and its vessels.

Many babies who are born with IAA also have DiGeorge syndrome, which is also a genetic disorder caused by the missing part of the same chromosome. Children who are born with DiGeorge syndrome can suffer from repeated infections and facial defects such as cleft lip.

Although it is rare, IAA is a life-threatening condition and must be treated right away. Babies who are born with IAA usually show symptoms right away.

What are the symptoms of interrupted aortic arch?

Children who have IAA may have the following symptoms:

  • Weakness and fatigue
  • Rapid breathing
  • Rapid heartbeat
  • Poor feeding habits

In addition, the baby’s skin may appear gray in certain areas because blood is not reaching that part of the body.

Children who are born with IAA may also have an atrial septal defect (ASD) or ventricular septal defect (VSD). A septal defect is a hole in the septum, the wall in the middle of the heart. In babies who have IAA, a ventricular septal defect allows some oxygenated blood to move from the left ventricle to the right ventricle, for circulation in the body.

Babies who have IAA may also have other heart defects, such as truncus arteriosus or transposition of the great arteries.