Congenital heart defects in children

Overview

A congenital heart defect is a cardiac condition that affects the structure of the heart of children since birth.

There are many types of congenital heart defects. Some are mild and do not require treatment while others can be more serious and needed treatment.

There are many types of congenital heart disease such as the following:

• Atrial septal defect (ASD)
• Atrioventricular canal defect
• Aortic coarctation
• Bicuspid aortic valve
• Congenital disease of the mitral valve
• Double-outlet right ventricle
• Ebstein anomaly
• Eisenmenger syndrome
• Hypoplastic left heart syndrome
• Kawasaki disease
• Long QT syndrome
• Partial anomalous pulmonary venous return
• Patent ductus arteriosus (PDA)
• Patent foramen ovale
• Pulmonary atresia
• Pulmonary atresia with intact ventricular septum
• Pulmonary atresia with ventricular septal defect
• Pulmonary valve stenosis
• Tetralogy of Fallot
• Total anomalous pulmonary venous return (TAPVR)
• Transposition of the great arteries
• Tricuspid atresia
• Truncus arteriosus
• Vascular rings
• Ventricular septal defect (VSD)
• Wolff-Parkinson-White (WPW) syndrome

Although there are unknown causes to congenital heart defects, there are some risk factors for these diseases. They include genetics, some health concerns, certain kinds of medications, bad environmental factors and lifestyle choices like smoking.

Symptoms

A severe kind of congenital heart defect, likely to be detected soon after birth with the following signs and symptoms:

• Cyanosis, which causes the baby’s lips, tongue or fingernails to turn blue
• Panting
• Swollen legs, abdomen or eyes
• Poor weight gain due to trouble breathing during feedings

If your baby has a less severe congenital heart defect, the doctor might not be able to detect but you should still observe the following signs and symptoms:

• Regularly having trouble breathing while doing physical activities such as exercising
• Getting tired easily during exercise
• Falling unconscious during exercise
• Swollen hands, ankles or feet

You are recommended to seek medical consultations if you think your child has any signs or symptoms of this disease. The doctor will be able to make a proper diagnosis on the type of cardiac problem that your child is suffering.

Causes

The heart has four chambers, two on the right and other two on the left, which function to pump blood to the rest of the body.

The right chambers are responsible for pumping blood to the lungs through the pulmonary arteries. Oxygen is absorbed into the blood in the lungs. Then the oxygenated blood travels through pulmonary veins to back to the left side heart chamber.

This left side is responsible for pumping this oxygen-rich blood to the aorta, which is the main artery that delivers oxygenated blood to the other organs throughout the body.

A baby tends to develop a congenital heart defect in the first six weeks of pregnancy, during the development of the heart and major blood vessels.

There are some categories of congenital heart defects as follows:

• Changes of blood flow channels in the heart or blood vessels: can be caused by many things, including a leaky wall of a heart chamber and irregularities of blood vessels. It may cause blood to flow in certain unnatural directions, or lead to mixing of oxygen-poor and oxygen-rich blood, causing the organs to receive less oxygen, which makes the heart and lungs work harder.

There are many defects that are included in this category of congenital heart defects, such as:

• • Atrial septal defect. A hole between the upper heart chambers, or the atria.
  • Ventricular septal defect. A hole in the wall between the right and left lower heart chambers, or the ventricles.
  • Patent ductus arteriosus that stays open. Patent ductus arteriosus is a natural channel that connects the lung artery to the aorta. Naturally, it remains open while the baby is still in the womb, and will close within the first few hours since the baby is born. However if it is kept open it will cause irregular directions of blood flow between the two arteries.
  • Total or partial anomalous pulmonary venous connection. Occurs when some or all pulmonary veins are connected to a wrong area or areas of the heart.
• Congenital heart valve problems: Heart valves open and close to allow blood to flow through the heart chambers and the blood vessels in the natural directions. Heart valve disease interferes with the opening/closing mechanism of a valve. This makes blood flow irregularly which can cause stenosis, where a valve gets thickened and cannot open completely, and regurgitation which is caused by a valve that cannot naturally close.

There are many congenital heart valve conditions, including:

• • Aortic stenosis. While a normal aortic valve has three flaps, this condition causes the valve of a baby to have only one or two flaps. This means it is harder for blood to flow through the valve, and the heart is forced to work harder to pump the blood. Over time, the heart will be enlarged and its muscle will be thickened.
  • Pulmonary stenosis. This condition causes the pulmonary valve to become thickened, obstructing the blood flow through the valve.
  • Ebstein anomaly. This condition causes malformation and leakage of the tricuspid valve. This valve separates the right upper heart chamber, or atrium, from the right lower chamber, or ventricle.
• Combination of congenital heart defects: are complex condition and may cause completely altered blood flow directions and severe underdevelopment of the heart chambers and include:
  • Pulmonary atresia. The pulmonary valve lets blood from the heart to the lungs. The valve does not naturally develop, making blood unable to flow to the lungs and decreases the absorption of oxygen in the organ.
  • Tricuspid atresia. In this disease, there is no formation of the tricuspid valve, and the area of the valve is instead replaced by a lump of tissue between the right upper heart chamber, or atrium, and the right lower chamber, or ventricle, which leads to reduction of blood flow and underdevelopment of the right ventricle.
  • Transposition of the great arteries. Caused by reversion of the two main arteries that deliver blood out of the heart which can be categorized into two types: transposition of the great arteries, which in most cases can be detected while the baby is still in the womb or right after birth and Levo-transposition of the great arteries (L-TGA), which occurs less frequently but causes distinct symptoms.
  • Hypoplastic left heart syndrome. This condition is caused by an improper development of the left side of the heart, making the area unable to pump enough blood to the organs around the body.

Risk factors

Most congenital heart defects start developing abnormalities when the baby is still in the womb with a developing heart.

There are no known exact causes of this kind of disorders, but certain risk factors have been found to increase the risk of these diseases. They include:

• Rubella. This German measles can disrupt the development process of the heart of a baby in the womb therefore women should get a blood test prior to pregnancy to check for immunity. Rubella vaccines are also available as a preventive measures.
• Diabetes. This chronic disease can put a baby in the womb at risk of a congenital heart defect. That is why a woman should carefully monitor and control her blood sugar level before and during pregnancy.
• Medications. Pregnant women who take some group of medicine face a higher risk of having a baby with a congenital heart defect. These include thalidomide, angiotensin-converting enzyme (ACE) inhibitors, statins, and the acne medication isotretinoin.
  Certain medications to treat epilepsy or anxiety are also a risk factor of a congenital heart defect therefore its necessary for women to discuss the medication they are taking with a doctor prior to pregnancy.
• Alcohol consumption while being pregnant. If a pregnant woman consumes alcoholic beverages, her baby in the womb faces a higher risk of developing a congenital heart disease.
• Smoking. A pregnant woman who smokes puts her baby in the womb at risk of a congenital heart defect.
• Family history and genetics. A baby can inherit a congenital heart defect from its family member or develop a disease of this kind due to a genetic disorder. It might be Down syndrome, where a baby has an extra 21st chromosome, or absence of certain genetic material on chromosome 22.