TGA Heart Defect

Transposition of the great vessels is a very serious and rare congenital defect in which the two main arteries, aorta and pulmonary artery are reversed.

It changes the way of blood circulation leading to shortage of oxygen in the blood to the rest of the body and fully oxygenated blood to the lungs.

Without adequate oxygen supply all body functions are seriously impaired. This disorder is detected either prenatally or within first few hours of life. Correction should be done soon after the birth.

Transposition of great arteries has the following symptoms in the newly born baby:

• Blue color of the skin.
• Shortness of breath.
• Lack of appetite.
• Poor weight gain.

Transposition of the Great Arteries is caused by a developmental defect during the formation of heart. The cause of this defect is unknown. Under normal circumstances the pulmonary artery which carries blood from heart to lungs Is attached to right ventricle and the aorta which carries blood to the rest of the body is attached to the left ventricle.

But in this disorder the position of pulmonary artery and aorta are switched resulting in blood circulation impairment. Oxygen poor blood is supplied to the rest of the body and blood rich in oxygen is supplied to the lungs with high pressure.

Circulation of poor oxygenated blood gives the skin a blue tint (cyanosis) therefore it is called a congenital heart defect.

Transposition of great arteries is a life-threatening disorder which requires immediate care and it can be diagnosed easily by the doctor by bluish color of the skin. Sometime it can be accompanied by patent ductus arteriosus (a hole between the aorta and pulmonary artery) which allows mixing of blood which cannot be promptly diagnosed.

There are some other similar heart conditions that is characterized by cyanosis. Therefore, to be sure of the diagnosis physical examination cannot be trusted alone.

The following tests can be used:

• Echocardiogram- ultrasound waves are passed through heart to get moving images on the video screen.
• Cardiac Catheterization- This is done only when echocardiogram is not showing enough information. During this test, the doctor inserts a thin flexible tube into the artery or vein in the baby’s groin and directs it up to the heart. This make the heart structures visible on X-ray using a dye that is injected through the catheter.
• Chest X-ray- It allows to see the see and position of the aorta and pulmonary artery.
• Electrocardiography- this procedure records the electrical activity of the heart.

Transposition of the great arteries can be treated by surgery only. Before surgery the following things must be done:

• taking medications like prostaglandin E1 helps to keep the connection between aorta and pulmonary artery open thus allowing mixing of blood until surgery can be performed.
• Atrial septostomy- this procedure is done using cardiac catheterization rather than surgery. It allows oxygen rich and oxygen poor blood to be mixed and results in better oxygen supply. Surgery- the following options are included in surgery.
• Arteria switch operation- during this procedure the pulmonary artery and aorta are moved to their normal positions. If the baby has ventricular septal defect or atrial septal defect these holes are usually closed during operation.

After surgery the following things should be taken:

• Care of the baby will need life-long follow up care with a cardiologist.
• The child should avoid certain activities and certain complications may also arise due to the surgery.

Pregnancy

If the transposition is diagnosed, then the arteries can be repaired only in a healthy pregnancy. But specialized care is needed.

In most cases transposition of the great arteries cannot be prevented. But if there is a family history then talking with a genetic counselor and a cardiologist should be considered before getting pregnant.

It is recommended to have a healthy pregnancy and all immunizations should be taken accordingly.

No alternatives or homeopathic remedies can treat transposition of great arteries.

Some strategies have been laid down in order to cope with transposition of great arteries:

• seek support- taking help from family members and friends and gaining support from child’s cardiologist.
• record baby’s health history- writing down baby’s diagnosis, medications, surgery and other procedures with the dates would be helpful while recalling these events.
• talk about the concern’s- talking with the cardiologist about the risks and concern’s if needed.

There are several risks and complications associated with transposition of the great arteries.

Although the exact cause of transposition is unknown several conditions in the mother may lead to increase in the risk of developing transposition of great vessels in the baby:

• A history of rubella and other viral infections.
• Poor nutrition during pregnancy.
• Drinking alcohol during pregnancy.
• Smoking during pregnancy.
• A mother older than the age of 40.
• Diabetic mother and down syndrome in baby.

Life threatening complications can occur in untreated cases like:

• Hypoxia- lack of oxygen to tissues leading to their death.
• Heart Failure- heart is not able to pump enough blood to meet the body needs because the heart itself is receiving deoxygenated blood
• Lung Damage- the oxygen rich blood with great pressure goes to the lungs and causes its damage making it difficult to breathe.

Surgery is usually done with in the first week of life and is associated with some complications:

• Narrowing of the coronary arteries.
• Arrhythmias
• Heart muscle weakness leading to heart failure and impairment of heart valves.