Fig

Tetralogy of Fallot:

A set of four individual defects, including: 1) a ventricular septal defect; 2) an obstruction of blood flow from the right ventricle to the pulmonary arteries; 3) overriding of the aortic valve above the ventricular septal defect; and 4) an abnormally thickened right ventricle.

Fig. 7.8: Pulmonary Valve Stenosis:

An abnormally narrowed pulmonary valve, which is located between the right ventricle and the pulmonary artery.

Heart Murmur:

A noise produced from blood flowing through the heart or other blood vessels or through the lungs.

Neonate:

A newborn, or a child within the first several weeks after birth.

Fig. 7.9: Congenital Aortic Stenosis:

This defect is usually an abnormal narrowing of the aortic valve, which is located between the aorta and the left ventricle. There are, however, several different forms of this defect.

toms Include fatigue or a reduced ability to exercise. The child may stand out because he or she cannot keep up with the other children physically.

The diagnosis is often suspected after hearing a heart murmur and obtaining an electrocardiogram. An echocardiogram will likely identify the defect and allow a definitive diagnosis to be made. For simple pulmonary valve stenosis, a balloon catheter is used to dilate the valve, usually with good results. Sometimes surgery using the heart-lung machine is necessary. In some cases, there is also muscular obstruction within the right ventricle, and this tissue needs to be removed. The results, after balloon dilatation or surgery, are usually excellent. The chance of surviving these procedures is greater than 99 percent. The long-term results are usually excellent.

Congenital Aortic Stenosis

In this defect's simplest form, the aortic valve is abnormally narrowed (Fig. 7.9). Other variations of this defect include narrowing of the aorta immediately above the heart valve or a membrane obstructing blood flow below the aortic valve. In some

\ Narrowed / Aortic Valve cases, an abnormality of the muscle immediately below the heart valve causes obstruction. Children with severe forms of aortic stenosis are likely to have symptoms of heart failure and shortness of breath. This defect may be suspected because of a heart murmur or because of an abnormal ECG. Confirmation of the diagnosis would be made with an echocardio-gram. In some instances a cardiac catheterization may be necessary to make the diagnosis.

With the most severe forms, an infant may require emergency heart surgery to open the valve. Some pediatric heart centers use a balloon catheter to open the narrowed heart valve, thus postponing valve surgery until the child is older.

The decision to recommend heart valve surgery depends on how serious the obstruction is. This defect may be so mild that surgical intervention is unnecessary. If surgery is necessary in straightforward and uncomplicated forms of the disease, the chance of surviving the procedure is greater than 98 percent. The chance of surviving the surgery is somewhat lower in more complex forms of the disease, and surgery is higher risk in critically ill neonates. With a successful procedure, long-term results are often very good, although in many instances, a second heart valve operation may be needed later.

Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is one of the most severe and life-threatening malformations of the human heart. "Hypoplastic" means "underdeveloped," left heart refers to the structures that make up the left side of the heart, and syndrome means a group of things that appear together.

The job of the left heart is to receive oxygenated blood from the lungs and distribute it to the body. The left heart includes the left atrium (left filling chamber), the left ventricle (main pumping

Aortic Arch Mitral

chamber), the mitral valve (valve between the left atrium and the left ventricle), the aortic valve (valve between the left ventricle and the aorta), and the aorta. HLHS consists of a wide spectrum of malformations in which one or more of these structures are critically small (Fig. 7.10). Despite the variation that can exist in cases of HLHS, the net result is the same: The left side of the heart cannot do its job properly.

Unfortunately, this is not a rare condition. Data from the New England Regional Infant Cardiac Program found HLHS to be present at a rate of 0.163 per one thousand live births.

Without surgery, 99 percent of patients with HLHS will die shortly after birth. In 1983, Dr. William Norwood at Boston Children's Hospital reported that he had successfully operated on an infant in two separate stages about a year and a half apart. That two-stage operation has greatly improved the chance of survival for infants born with HLHS. Today, Norwood's two-stage repair has evolved into a three-stage repair performed over the first few years of the patient's life.

The goal of these three operations is to bypass the small left side of the heart by making the right ventricle the heart's main pumping chamber. Since the right ventricle will, therefore, no longer be available to perform its usual job of pumping blood to the lungs, the vessels that normally carry the unoxygenated blood (superior and inferior vena cavae) are connected directly to the lung arteries. The flow of unoxygenated blood to the lungs occurs passively without the benefit of an intervening pumping chamber. This type of passive pulmonary blood flow in a heart with only one good pumping chamber is called a Fontan operation — another variation is the Glenn operation. They are applicable not only in HLHS but also in other types of abnormal hearts with a single pumping chamber.

The advantage of the three-stage Norwood procedure is that these operations can almost always be performed; the disadvantage is that it requires three operations and still results in a heart with only one pumping chamber. Furthermore, the long-term results of using the right ventricle (instead of the left ventricle) to pump oxygenated blood to the body are not known.

Dr. Leonard Bailey at Loma Linda University has pioneered the use of newborn heart transplantation for the treatment of HLHS. If a donor heart is available, cardiac transplantation requires only one operation and produces a structurally normal heart with two pumping chambers. Unfortunately, about 25 percent of the newborns who would need a cardiac transplantation die of complications while waiting for a donor heart. After cardiac transplantation, the patient must take antirejection medication for the rest of his or her life. The side effects of these medicines can become serious over time, and rejection of the transplanted heart can occur. Incidentally, Bailey created quite an uproar in the news media in 1984 when a human heart donor was not

Fig. 7.10: Hypoplastic Left Heart Syndrome: This literally means underdeveloped left heart. Some or all of the structures on the left side of the heart, including the heart's main pumping chamber, are undersized. It is a very serious congenital defect.

available and he transplanted the heart of a baboon into a desperately ill twelve-day-old premature girl known as "Baby Fay," who was suffering from HLHS.

At this point it is not clear which surgical treatment is better for hypoplastic left heart syndrome. Both, however, are an improvement on previously available treatments. HLHS used to be 100 percent fatal during the first year of life. Although pediatric heart surgeons tend to hold strong opinions, neither the Norwood procedure nor cardiac transplantation is a perfect treatment option for HLHS, and neither approach is clearly superior. In the best centers, roughly 60 percent of patients who undergo either surgery are alive ten years later.

Ectopia Cordis

This is a rare congenital heart defect. As of 1989, only 219 cases had ever been reported in the medical literature.

Fig. 7.11: Ectopia Cordis:

A rare condition in which an infant is born with its heart mislocated. In some cases, the heart is even located outside of the chest cavity.

Fig. 7.11: Ectopia Cordis:

A rare condition in which an infant is born with its heart mislocated. In some cases, the heart is even located outside of the chest cavity.

Ectopia means displacement, and cordis means heart.

There are four types of this defect: the heart may be located in the neck, either partially or completely in the abdomen, or, almost unbelievably, outside of the body on the chest (Fig. 7.11). Many infants suffering from this defect have other abnormalities inside the heart as well.

When the heart is outside of the body, it is recommended that the infant undergo immediate surgery to put the heart back into the chest. The first successful surgery of this type was performed by Dr. Narish Saxena at the Children's Hospital of Philadelphia in 1975. This case, in which I was involved, was that of a child who had to undergo multiple innovative surgeries and practically lived the first few years of his life in the hospital.

Thoracopagus Twins

Identical twins occur at an incidence of four per one thousand births. Conjoined twins are identical twins who are joined to each other in some place on their bodies. This form of twin is much rarer and has an incidence of one per fifty thousand to one hundred thousand births. In 1811, in the country of Siam (now Thailand), a Chinese mother gave birth to identical twins joined at the hip. The boys were named Eng and Chang, and they lived unseparated until their death at age sixty-three years. They became famous as a result of being promoted as "freaks" by P.T. Barnum, who called them the "Siamese Twins," and the term has been used since then for all twins who are born attached to each other.

Most Siamese twins are born dead, but there are about four hundred sets known to have lived, ranging in life span from just a few hours to the sixty-three years of Eng and Chang. They can be joined in various places on the body, including the lower back, the abdomen, the hip, the leg, and even the head. About 40

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Pregnancy Diet Plan

Pregnancy Diet Plan

The first trimester is very important for the mother and the baby. For most women it is common to find out about their pregnancy after they have missed their menstrual cycle. Since, not all women note their menstrual cycle and dates of intercourse, it may cause slight confusion about the exact date of conception. That is why most women find out that they are pregnant only after one month of pregnancy.

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