Congenital Heart Syndrome

A congenital heart defect (CHD) is an abnormality in the structure or function of the heart. This can include circumstances that affect the walls of the organ, blood vessels that transport blood to and from it, and the valves that regulate blood flow. Some CHDs are minor, and cause no noticeable symptoms. Others are severe, and can place the patient's life at risk.

Symptoms vary according to the type of defect suffered, as well as its severity. In this article, we'll explore a few of the most common simple CHDs, including septal defects and valve problems.

Atrial Septal Defect

Inside the heart, the left atrium and ventricle are separated from the right atrium and ventricle by a wall. This wall is called the septum. It prevents deoxygenated
blood on the right side from mixing with newly-oxygenated blood on the left side. Many babies are born with a hole in this wall. When the hole is located between the atria (two upper chambers of the heart), it is called an atrial septal defect (ASD).

When an ASD is small, symptoms may be barely noticeable.
Even though blood between the right and left sides is allowed to mix, the amount that does so is negligible, and thus does not pose a significant problem. When the defect is bigger, symptoms are more pronounced. A larger volume of oxygenated blood in the left atrium flows back in the right atrium rather than being pumped out of the heart to the rest of the body. Treatment is often necessary.

Ventricular Septal Defect

A ventricular septal defect (VSD) is similar to an ASD. The difference is that the hole is located between the two ventricles (lower chambers of the heart). The effect is essentially the same. Oxygen-rich blood that would otherwise be pumped into the aorta is allowed to flow back into the right ventricle. Consequently, less oxygen is available to the rest of the body.

A small VSD is unlikely to have severe consequences. A larger hole, however, can cause fatigue, difficulty taking deep breaths, and in extreme cases, cyanosis due to a marked lack of oxygen in the blood cells. Occasionally, a large ventricular septal defect can cause pulmonary hypertension, a condition where high blood pressure causes the heart to work harder. Unless the septal hole is corrected, the patient may eventually experience heart
failure.

Valve Abnormalities

The heart is equipped with valves that manage blood flow between the chambers and the arteries attached to them.
The right atrium and ventricle are separated by the tricuspid valve; the left atrium and ventricle are separated by the mitral valve; blood flows from the right ventricle to the pulmonary arteries through the pulmonary valve; and blood moves from the left ventricle to the aorta through the aortic valve.

These valves can be diseased in a few ways. First, they might fail to close completely, allowing blood to flow backward. Second, they may be stiff, and thus fail to open properly. When this happens, the chambers are unable to empty. Third, a valve might be unable to open at all.

Signs of a valve defect vary based on which valve is affected. For example, a regurgitant - or, "leaking" - mitral valve will prevent oxygen-rich blood from being circulated to the body. This leads to fatigue and related issues. A stenotic - or, stiff - pulmonary valve can increase blood pressure in the right ventricle, leading to possible heart failure.

It is worth emphasizing that mild congenital heart defects may not require any treatment. In fact, many adults live with a simple CHD without realizing they have one. If a disorder is severe, however, treatment may be necessary to improve the patient's quality of life. Some defects, such as an ASD, can be corrected with the use of a catheter. Others might require invasive
surgery.