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Blue Baby Heart Defect:

Tetralogy of Fallot:

The Tetralogy of Fallot is a birth defect that changes normal blood flow through a baby's heart.

Some background about how a normal heart works:

A healthy heart has four chambers: the right atrium and right ventricle, and the left atrium and left ventricle. After delivering oxygen to the body, oxygen-poor blood flows into the right atrium. When the right atrium contracts, it loads blood into the relaxed right ventricle. Then the right ventricle contracts, sending blood to the lungs through the pulmonary artery. The blood picks up oxygen in the lungs and then returns to the left atrium. The left atrium contracts, filling the relaxed left ventricle with blood.The left ventricle contracts to pump and deliver oxygen-rich blood to the body through the aorta.

  • Tetralogy of Fallot is a birth defect made up of four problems with the heart and its blood vessels and they are:

  1. A Ventricular Septal Defect or VSD, is a hole in the wall between the two ventricles. The hole allows oxygen-rich blood to mix with oxygen-poor blood.

  2. An overriding aorta means the aorta is shifted slightly from its usual location on the heart. It sits right over the Ventricular Septal Defect. This allows blood from both ventricles to flow through the aorta. As a result, some oxygen-poor blood may flow to the body.

  3. Pulmonary stenosis means that the main pulmonary artery is narrowed, and the pulmonary valve doesn't open all the way. As a result of the narrowing, less blood reaches the lungs.

  4. Right ventricular hypertrophy means the wall of the right ventricle is thicker than normal. This is thought to happen in response to blood flow through the ventricular septal defect, and from having to work harder to pump blood through the narrowed pulmonary artery, which results in increased blood pressure.

Together, these four problems may prevent enough oxygen from reaching the baby's body. This may result in episodes of a condition called "cyanosis," or blue baby. In this condition, the baby's skin, lips, and fingernails may have a blueish tint.

How can we treat it?

The treatments for Tetralogy of Fallot are surgical procedures to help fix the following four heart problems.

Tetralogy of Fallot is repaired with open-heart surgery, either soon after birth or in infancy. Surgical procedures may include temporary and complete repairs. Your child may not be ready for a complete repair right away. In this case, a temporary repair such as a shunt or a stent can be placed until a complete repair can be done.

Both repairs increase blood flow to the lungs and improve oxygen levels in the blood delivered to the body.

  • During a shunt procedure, the surgeon will open the chest wall to place a tube called a shunt between a branch of the aorta and the right pulmonary artery. The shunt will provide another path for blood to get to the lungs to pick up oxygen.

  • During a stent procedure, a tube called a catheter will be inserted through a small incision into a blood vessel in the leg. The cardiologist will use the catheter to place a device called a stent inside the narrowed area of the pulmonary artery. This allows more blood to flow to the lungs. A complete repair is done when your child is strong enough for the procedure.

  • During the procedure, the pulmonary stenosis defect may be repaired in the following ways. If the main pulmonary artery is too small, it will be widened with a patch. If the pulmonary valve is too small, it may be widened with a patch or replaced. If extra heart muscle is blocking blood flow below the pulmonary valve, the surgeon will remove the muscle tissue. These repairs will improve the flow of oxygen-poor blood from the right ventricle to the lungs. As a result, the blood will get enough oxygen for the body's needs.

  • To fix the ventricular septal defect, the surgeon will cover the hole with a patch. The patch will prevent the mixing of oxygen-poor blood with oxygen-rich blood. As a result, only oxygen-rich blood will flow out of the aorta to the body from the left ventricle.

  • Over time, fixing the pulmonary stenosis and closing the ventricular septal defect will also fix the right ventricular hypertrophy. Since the right ventricle won't have to work as hard to pump blood, its wall will return to normal thickness.

If your child still has a shunt from the temporary repair, it will either be removed or clipped shut at the end of this procedure. Similarly, if your child had a stent placed, it will also be removed.


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