Explanation of Karter's heart defects! :)

Here is a great explanation on Karter's AV Canal Defect

What is it?

Many terms are used to describe this complex defect. They include atrioventricular (AV) canal, complete AV canal, complete common AV canal and endocardial cushion defect.
Atrioventricular (AV) canal defect is a large hole in the center of the heart. It’s located where the wall (septum) between the upper chambers (atria) joins the wall between the lower chambers (ventricles). This septal defect involves both upper and lower chambers. Also, the tricuspid and mitral valves that normally separate the heart’s upper and lower chambers aren’t formed as individual valves. Instead, a single large valve forms that crosses the defect in the wall between the two sides of the heart.

What causes it?

In most children, the cause isn’t known. It’s a very common type of heart defect in children with a chromosome problem, Trisomy 21 (Down syndrome). Some children can have other heart defects along with AV canal.

How does it affect the heart?

Normally, the left side of the heart only pumps blood to the body, and the heart’s right side only pumps blood to the lungs. In a child with AV canal defect, blood can travel across the holes from the left heart chambers to the right heart chambers and out into the lung arteries. The extra blood being pumped into the lung arteries makes the heart and lungs work harder and the lungs can become congested.

How does the AV canal defect affect my child?

A child with AV canal defect may breathe faster and harder than normal. Infants may have trouble feeding and growing at a normal rate. Symptoms may not occur until several weeks after birth. High pressure may occur in the blood vessels in the lungs because more blood than normal is being pumped there. Over time this causes permanent damage to the lung blood vessels.
In some infants, the common valve between the upper and lower chambers doesn’t close properly. This lets blood leak backward from the heart’s lower chambers to the upper ones. This leak, called regurgitation or insufficiency, can make the heart work harder, too.

What can be done about the defect?

An AV canal can be fixed. Open-heart surgery is needed to repair the defect. Unlike some other types of septal defects, the AV canal defect can’t close on its own. Medicines may be used temporarily to help with symptoms, but they don’t cure the defect or prevent permanent damage to the lung arteries.

In an infant with severe symptoms or high blood pressure in the lungs, surgery must usually be done in infancy. During the operation, the surgeon closes the large hole with one or two patches. Later the patch will become a permanent part of the heart as the heart’s lining grows over it. The surgeon also divides the single valve between the heart’s upper and lower chambers and makes two separate valves. These will be made as close to normal valves as possible.
If an infant is very ill, or has a defect that may be too complex to repair in infancy, a temporary operation to relieve symptoms and high pressure in the lungs may be needed. This procedure (pulmonary artery banding) narrows the pulmonary artery to reduce the blood flow to the lungs. When the child is older, an operation is done to remove the band and fix the AV canal defect with open-heart surgery.

Here is great explanation of her Tetralogy of Fallot (her second heart defect):

What is it?

Tetralogy of Fallot refers to a combination of abnormalities with four key features: 1) A ventricular septal defect (a hole between the ventricles) and 2) obstruction of blood flow from the right ventricle to the lungs (pulmonary stenosis) are the most important. Sometimes the pulmonary valve isn’t just narrowed but is completely obstructed (pulmonary atresia). Also, 3) the aorta (major artery from the heart to the body) lies directly over the ventricular septal defect and 4) the right ventricle develops hypertrophy (thickened muscle).
Because of the pulmonary stenosis, blood can’t get to the lungs easily, so the blood doesn’t get as much oxygen as it should. Because the aorta overrides the ventricular septal defect, blood from both ventricles (oxygen-rich and oxygen-poor) is pumped into the body. People with unrepaired tetralogy of Fallot are often blue (cyanotic) because of the oxygen-poor blood that’s pumped to the body.

What causes it?

In most cases, the cause isn’t known although in some patients, genetic factors play a role. It’s a common type of heart defect. It may be seen more commonly in patients with Down syndrome (in association with AV canal defects) or DiGeorge syndrome. Some patients can have other heart defects along with tetralogy of Fallot.

How does it affect the heart?

Normally the left side of the heart only pumps blood to the body, and the heart’s right side only pumps blood to the lungs. In a patient with tetralogy of Fallot, blood can travel across the hole (VSD) from the right pumping chamber (right ventricle) to the left pumping chamber (left ventricle) and out into the body artery (aorta). Obstruction in the pulmonary valve leading from the right ventricle to the lung artery prevents the normal amount of blood from being pumped to the lungs. Sometimes the pulmonary valve is completely obstructed (pulmonary atresia).

All of this information was provided by: www.americanheart.org