The site I received this information from, contained a flash movie of the functions of a healthy heart vs a heart with the certain defect. (AWESOME!) Just click on the Flash movie button to view.
I don't know why they Interrupted Aortic Arch Definition didn't contain a movie clip. :( I am extremely curious how they fix that.
What is truncus arteriosus?
Instead of having a separate pulmonary artery and aorta, each with their own three-leafed valves, a baby with truncus arteriosus has only one great blood vessel or trunk leaving the heart, which then branches into blood vessels that go to the lungs and the body.
This great vessel usually has one large valve which may have between two and five leaflets. Usually this great vessel sits over both the left and right ventricle. The upper portion of the wall between these two chambers is missing resulting in what is known as a ventricular septal defect (VSD). In rare cases, the ventricular septal defect is absent.
What is a Ventricular Septal Defect?
The heart has four chambers: a right and left upper chamber called an atrium and a right and left lower chamber called a ventricle.
In the normal heart, the right and left chambers are completely separated from each other by a wall of muscle called a septum. The right atrium is separated from the left atrium by the atrial septum and the right ventricle is separated from the left ventricle by the ventricular septum.
It is normal for all infants to be born with a small hole between the two atria, which usually closes within the first few weeks of life.
Normally there is no hole between the two ventricles, but some infants are born with these holes called ventricular septal defects.
Ventricular septal defects are among the most common congenital heart defects, occurring in 0.1 to 0.4 percent of all live births and making up about 20 to 30 percent of congenital heart lesions. Ventricular septal defects are probably one of the most common reasons for infants to see a cardiologist.
What is Interrupted Aortic Arch / ventricular septal defect?
Interrupted Aortic Arch (IAA) is the absence or discontinuation of a portion of the aortic arch. There are three types of Interrupted Aortic Arch, and they are classified according to the site of the interruption.
Type A: the interruption occurs just beyond the left subclavian artery. Approximately 30 percent to 40 percent of the infants with Interrupted Aortic Arch have Type A.
Type B: (shown in diagram): the interruption occurs between the left carotid artery and the left subclavian artery. Type B is the most common form of Interrupted Aortic Arch. It accounts for about 53 percent of reported cases.
Type C: the interruption occurs between the innominate artery and the left carotid artery. Type C is the least common form of Interrupted Aortic Arch, accounting for about 4 percent of reported cases.
Interrupted Aortic Arch is thought to be a result of faulty development of the aortic arch system during the fifth to seventh week of fetal development. This defect is almost always associated with a large ventricular septal defect (VSD). Patients with Interrupted Aortic Arch (particularly those with type B) often have a chromosomal abnormality called DiGeorge syndrome. In addition to Interrupted Aortic Arch, patients with DiGeorge syndrome may have problems with low calcium, developmental delay, and immune system abnormalities.
We opted not to do any genetic testing beyond the blood screen done in the office.
The baby will have genetic testing done shortly after birth along with an echo.