What is ASD?PDA?Tetralogy of Fallot?

What is ASD? In this defect there is a hole between the top chambers (receiving chambers or atria). Because of the higher pressure in the left side of the heart, oxygenated blood flows through the hole from the left to the right side of the heart, and back to the lungs, in addition to the normal flow. There are three types of Atrial Septal Defect; the most common is when there is a hole in the middle of the central heart wall. Holes in the lower part of the septum, called the primum defect (partial atrioventricular septal defect), are often associated with a problem of the mitral valve that often results in a leak. Less common are sinus venosus defects or holes in the top of the septum. These are associated with an abnormality of the right upper lung vein. Symptoms Generally patients with an ASD defect will exhibit no symptoms and the problem is only found when a routine clinical examination detects a heart murmur. Occasionally children with this problem will exhibit poor weight gain and a failure to thrive, and if there is mitral valve leakage there may be early symptoms of breathlessness. Treatment Small holes which allow little blood flow from left to right generally cause no problems. If they are located in the middle portion of the central heart wall, they may even close on their own. However, moderate and large holes do not close, and the extra work over the years places a strain on the right side of the heart causing an enlargement of both pumping chambers. Therefore, treatment (surgery) is usually recommended in the first few years of life for larger holes, before excessive strain has been placed on the heart. What is PDA? This defect is the continuance of a direct connection between the aorta and the lung (pulmonary) artery, which normally closes shortly after birth. A baby in the womb is supplied oxygen by the placenta via the umbilical cord. The baby's lungs are not expanded and require only a small amount of blood for them to grow. The ductus is a blood vessel that allows blood to bypass the baby's lungs. Generally the ductus close within a few days of birth, and the connections between the two sides of the heart no longer exist. The resistance to blood flow quickly falls with the onset of breathing. In some babies with Down syndrome the ductus fails to close. This causes higher pressure in the left side of the heart and increases the amount of blood flowing into the lungs. Symptoms If the ductus has partially closed and only a narrow connection remains, the baby won’t show symptoms. If the connection is larger, the baby may be breathless and tired and show poor weight gain. Treatment If the ductus remains open for more than three months, it is unlikely to close on its own and surgical closure is recommended. What is Tetralogy of Fallot? A small percentage of babies with Down syndrome have this complex heart condition which combines the most common defect associated with Down syndrome, AVSD, with Tetralogy of Fallot. This anomaly includes four different heart problems: a hole between the top chambers and a hole between the bottom chambers combined mitral and tricuspid valves (common atrioventricular valve) narrowed pulmonary artery (from heart to lungs) or the area under or above the valve, or all three thickening of the right bottom chamber (ventricle) Symptoms The combination of these defects early in life almost seems to balance out such that the child may be rather blue, but not too breathless. There can, of course, be too much blueness or too much breathlessness, depending on the severity of the different conditions. Treatment The type of surgery depends on the severity of the AVSD or the Fallots. Usually, the children are quite blue and require a BT shunt to increase the amount of blue going to the lungs. Then another operation is performed later – usually at 1-2 years of age – so that the holes can be closed, the valves repaired, and the way out to the lung artery widened.