Congenital Heart Disease: A-to-Z Guide from Diagnosis to Treatment to Prevention

Introduction:

A baby’s heart begins to beat as early as 22 days into the pregnancy. But it doesn’t always progress properly.

What is congenital heart disease?

Complex folding and development of the heart before a baby is born results in distinct chambers, separated by walls and valves. Important large blood vessels enter and leave the heart. The arrangements change again around the time of birth, when oxygen begins to arrive through the lungs instead of the umbilical cord.

Problems in early development, or in adjusting from fetal circulation to life in the outside world, can result in congenital heart disease (CHD).

There are many types of congenital heart disease. They can be very mild, or they can be quite serious. Some require surgical treatment.

The eight most common types are listed below:

• Ventricular septal defect (VSD): This is the most common type of congenital heart disease. In the case of VSD, the wall between the two largest chambers of the heart (the ventricles) does not finish forming.
• Atrial septal defect (ASD): The wall between the two entry chambers of the heart (the atria) does not finish forming.
• Patent ductus arterious (PDA): A normal fetal blood vessel that connects the pulmonary artery to the aorta fails to close at the time of birth.
• Coarctation of the aorta (COA): The aorta leaves the left ventricle as the largest artery in the body. A coarctation is an abnormal narrowing of a segment of the artery.
• Tetralogy of Fallot (TOF): Classically, this condition is a combination of four defects: 1) a large VSD, 2) narrowing of the exit to the right ventricle (pulmonary stenosis), 3) overdevelopment of the muscular wall of the right ventricle (right ventricular hypertrophy), and 4) the aorta is positioned above the wall separating the two sides of the heart (an overriding aorta).
• Pulmonary valve stenosis (PS): This is a narrowing of the valve at the exit of the right ventricle that directs blood through the pulmonary artery to receive oxygen from the lungs.
• Aortic valve stenosis (AS): This is a narrowing of the valve at the exit of the left ventricle that directs blood into the aorta, where oxygenated blood flows to supply the body.
• Transposition of the Great Arteries (TGA): The aorta exits from the right ventricle, and carries oxygen depleted blood to the body; the pulmonary artery exits from the left ventricle and carries oxygen-rich blood to the lungs to receive oxygen. Without some type of additional defect that mixes the two circulations, the child cannot survive. This might be an ASD, VSD, or PDA.

Who gets congenital heart disease?

About one in 200 children are born with congenital heart disease of some form. It is more common in babies born early, but it can happen to anyone.

Many factors can lead to congenital heart disease, but it sometimes runs in families. There is a new and rapidly growing field of genetics, human cardiovascular genetics, that seeks to discover the genes involved in heart development and heart disease.

A variety of pediatric conditions are sometimes associated with specific types of heart defects, for example ASD, VSD, or other heart defects in children with Down syndrome.

Conditions in pregnant women (such as diabetes or rubella) can also lead to congenital heart disease. Some medications, such as those used to treat seizures, can lead to CHD in children. Drinking alcohol during pregnancy is another cause of CHD.

What are the symptoms of congenital heart disease?

Some forms of congenital heart disease may have no symptoms. They might be suspected by hearing a murmur on a routine physical examination. Sometimes symptoms such as poor feeding, shortness of breath, poor growth, frequent pneumonias, sweating, or dusky coloring lead to the diagnosis.

Some forms of congenital heart defects show up as medical emergencies, perhaps with respiratory distress, cardiac distress, or blue coloring.

Is congenital heart disease contagious?

No, although infectious diseases such as rubella can lead to CHD.

How long does congenital heart disease last?

This varies with the type and extent of the defect. Some will last until they are corrected surgically–sometimes requiring a series of operations. Some forms of CHD, however, do heal spontaneously. Many VSDs, for instance, close during infancy or toddlerhood with no treatment.

How is congenital heart disease diagnosed?

The diagnosis is suspected based on the history and physical exam. Further workup may include studies such as EKGs, chest x-rays, and echocardiograms.

How is congenital heart disease treated?

The treatment depends on the type and the extent of the defect. It might involve medications, operations, or sometimes no treatment at all other than just watching and waiting for it to heal on its own.

How can congenital heart disease be prevented?

Congenital heart disease is often impossible to prevent. Avoiding toxic exposures, such as drinking alcohol during pregnancy, prevents some CHD. Similarly, avoiding certain infections during pregnancy, such as rubella (preventable by immunization), can prevent some CHD.

Related concepts:

AS, ASD, Aortic Valve Stenosis, Atrial Septal Defects, CHD, Coarctation of the Aorta, Hypoplastic Left Ventricle, Patent Ductus Arteriosus, PDA, PS, Pulmonary Valve Stenosis, Tetralogy of Fallot, TGA, TOF, Total Anomalous Pulmonary Venous Return, Transposition of the Great Arteries, Tricuspid Atresia, Truncus