What is CHD?

 

Congenital heart defects (CHDs) are problems present at birth that affect the structure or function of the heart. They can affect how blood flows through the heart and out to the rest of the body. There are many types of heart defects, with different degrees of severity based on size, location, and other associated defects. Common examples include holes in different areas of the heart and narrow or leaky valves. In more severe forms of CHDs, blood vessels or heart chambers may be missing, poorly formed, or in the wrong place.

 

What is the difference between congenital heart defect and congenital heart disease?

 

These terms are often used interchangeably and are nearly synonymous. However, there is a slight difference between them. A congenital heart defect refers specifically to a problem with the formation of the structure of the heart or major heart vessels in utero. Congenital heart disease refers to the clinical manifestation of an underlying anatomical defect, or more broadly describes functional problems which may be congenital, including certain arrhythmias.

 

What are critical congenital heart defects?

 

Critical CHDs (CCHDs) are defects that typically result in low oxygen levels in the newborn. Babies with critical CHDs usually require surgery or other procedures in the first year of life. Some examples of critical CHDs include coarctation of the aorta, transposition of the great arteries, hypoplastic left heart syndrome, and tetralogy of Fallot.

 

What is Hypoplastic Left Heart Syndrome?

 

Hypoplastic left heart syndrome (HLHS) is a congenital disability that affects normal blood flow through the heart. As the baby develops during pregnancy, the left side of the heart does not form correctly. Hypoplastic left heart syndrome is one type of congenital heart defect. Genetic means present at birth. Because a baby with this defect needs surgery or other procedures soon after birth, HLHS is considered a critical congenital heart defect (CCHD).

Hypoplastic left heart syndrome affects several structures on the left side of the heart that do not fully develop, for example:

 

The left ventricle is underdeveloped and too small.

The mitral valve is not formed or is very small.

The aortic valve is not formed or is very small.

The ascending portion of the aorta is underdeveloped or is too small.

Babies with hypoplastic left heart syndrome often also have an atrial septal defect, a hole between the heart's left and right upper chambers (atria).

 

 

When can CHDs be detected?

 

CHDs can be detected as early as the prenatal period or as late as adulthood (or escape detection altogether).  The more severe the form of CHDs, the more likely it is to be detected earlier.

 

How many babies are born each year with some form of CHD?

 

Of the nearly 4 million infants born in the United States each year, approximately 3% have some type of birth defect.  CHDs are the most common birth defect, occurring in about 1 in 110 births, that’s 1 child every 15 minutes born with CHD.  In the U.S. approximately 40,000 infants are affected each year.

 

How many babies are born each year with a critical CHD?

 

Approximately 1 in every 4 babies born with a CHD has a critical CHD and needs surgery or other procedures in the first year of life.

 

What risk factors and causes can lead to CHDs?

 

Although some CHDs have been linked to genetic disorders, maternal conditions, and environmental factors, the causes for the majority of CHDs are unknown.

 

Treatments

 

Some babies and children will need medicines to help strengthen the heart muscle, lower their blood pressure, and help the body get rid of extra fluid.  Some babies with hypoplastic left heart syndrome become tired while feeding and do not eat enough to gain weight. To make sure babies have a healthy weight gain, a special high-calorie formula might be prescribed. Some babies become extremely tired while feeding and might need to be fed through a feeding tube.

​

Surgery

 

Soon after a baby with hypoplastic left heart syndrome is born, multiple surgeries done in a particular order are needed to increase blood flow to the body and bypass the poorly functioning left side of the heart. The right ventricle becomes the main pumping chamber to the body. These surgeries do not cure hypoplastic left heart syndrome, but help restore heart function. Sometimes medicines are given to help treat symptoms of the defect before or after surgery. Surgery for hypoplastic left heart syndrome usually is done in three separate stages:

​

Norwood Procedure
This surgery usually is done within the first 2 weeks of a baby’s life. Surgeons create a “new” aorta and connect it to the right ventricle. They also place a tube from either the aorta or the right ventricle to the vessels supplying the lungs (pulmonary arteries). Thus, the right ventricle can pump blood to both the lungs and the rest of the body. This can be a very challenging surgery. After this procedure, an infant’s skin still might look bluish because oxygen-rich and oxygen-poor blood still mix in the heart.

​

Bi-directional Glenn Shunt Procedure   

This usually is performed when an infant is 4 to 6 months of age. This procedure creates a direct connection between the pulmonary artery and the vessel (the superior vena cava) returning oxygen-poor blood from the upper part of the body to the heart. This reduces the work the right ventricle has to do by allowing blood returning from the body to flow directly to the lungs.​

 

Fontan Procedure
This procedure usually is done sometime during the period when an infant is 18 months to 3 years of age. Doctors connect the pulmonary artery and the vessel (the inferior vena cava) returning oxygen-poor blood from the lower part of the body to the heart, allowing the rest of the blood coming back from the body to go to the lungs. Once this procedure is complete, oxygen-rich and oxygen-poor blood no longer mix in the heart and an infant’s skin will no longer look bluish.

​​

Heart Transplant

If the heart defect is very complex, or the heart becomes weak after the surgeries, a heart transplant may be needed.

 

Children affected by congenital heart defects face numerous challenges, both physical and emotional, from the moment they are born. It can affect children of every demographic.  It’s a lifelong disease requiring on-going, specialized care.