Transposition of the Great Arteries

What is Transposition of the Great Arteries?

Transposition of the great arteries is a rare congenital heart defect that results in the reversal of the two main arteries connected to the heart.

It is a serious condition that leads to changes in how blood circulates throughout the body, resulting in an oxygen shortage to muscles and organs. In many cases, it is found prenatally or in the baby’s first hours or weeks of life. Left untreated, children with the defect may experience severe complications or even death.

Transposition of the great arteries occurs while the baby’s heart is developing during fetal growth. Exactly why this happens is not yet known. The positions of the aorta and pulmonary artery are switched, which causes oxygen-poor blood to circulate into the body without first passing through the lungs. Likewise, oxygen-rich blood is circulated towards the lungs before it travels to the rest of the body.

Despite not knowing for certain what causes the condition, certain factors are thought to increase the chances of a baby being born with transposition of the great arteries. Some of these include the mother drinking alcohol or having poor nutrition during the pregnancy, being older than 40, and having uncontrolled diabetes. The defect is also more often seen in babies with Down syndrome.

What are the Symptoms of Transposition of the Great Arteries?

Symptoms of transposition of the great arteries are usually first seen in the hospital after birth and often include bluish skin, lack of appetite, shortness of breath, and poor weight gain.

In addition, there are numerous potential complications associated with the deformity, including heart failure, insufficient oxygen to tissues (hypoxia), and lung damage.

Transposition of the Great Arteries Causes

Transposition of the great arteries is a birth defect, caused by abnormal development of the heart during the early stages of fetal growth.

The defect causes the right artery used by reduced-oxygen blood (so-called ‘blue’ blood) and left artery used by oxygenated (or ‘red’) blood to connect to opposite sides of the heart. Without the proper conversion of blue blood (oxygen-depleted) into red blood (oxygen-enhanced), unoxygenated blood will occupy the infant’s body system, with fatal results.

A family’s medical history and genetics are linked to this heart condition. In some instances, it happens by chance. Transposition of the great arteries is a common cause of congenital heart disease with defects occurring in one percent of infants.

Heart defects can develop during pregnancy when mothers are taking medications for health disorders. Certain medications cause a reaction affecting the proper development of the heart’s composition.

How is Transposition of the Great Arteries Treated?

Surgery is always required to correct transposition of the great arteries in newborns. Before the procedure, medications may be given or an atrial septostomy might be done to manage the condition in the meantime.

The actual surgery will usually switch the two arteries back to their normal position. Less commonly, the atria of the heart may be switched instead.

Transposition of the Great Arteries Prevention

Transposition of the great arteries can’t be prevented, but it can be diagnosed in the early trimesters of pregnancy using a fetal echocardiogram or heart ultrasound. In most cases, family history of the disease mandates a prenatal ultrasound with an assessment of after-birth treatment. In rare situations, fetal interventions of the pulmonary artery or aorta corrective surgery of heart defects are possible.

There are no health alternatives to surgical correction for this heart defect. At birth, a cardiac procedure inserts a catheter into the heart of the infant allowing the mixing of oxygenated and unoxygenated blood. Depending on the health of the newborn, minimal heart surgery is an option to repair the defect.

Acute heart conditions are correctable with open-heart surgery switching the pulmonary artery and aorta back to the normal locations. After surgery monitoring includes making sure the infant is breathing and feeding on its own.