Transposition of the Great Arteries

Transposition of the Great Arteries

 

Definition

Transposition of the great arteries is a birth defect causing a fatal condition in which there is a reversal, or switch, in the truncal connections of the two main (great) blood vessels to the heart, the aorta and pulmonary artery.

Description

There are two great arteries, the pulmonary artery and the aorta. Normally, the pulmonary artery carries blood from the right ventricle to the lungs. The aorta carries blood from the left ventricle to the vessels of the rest of the body.
Normally, blood returning to the heart is depleted in oxygen. It goes first to the right atrium of the heart and then to the right ventricle where it is pumped to the lungs. While in the lungs, the blood picks up more oxygen. After the lungs, the blood flows to the left atrium, then the left ventricle, which pumps the blood out through the aorta to the rest of the body, thereby supplying the body with oxygenated blood.
Transposition of the great arteries results in oxygen-depleted blood going to the body. The reason is that the connection of the two great arteries is reversed. In this case, the aorta is connected to the right ventricle. Blood returning to the heart goes to the right atrium and ventricle, which is normal. Then, when the right ventricle pumps the blood out, it goes into the aorta for distribution throughout the body. At the same time, blood in the lungs goes to the left atrium, the left ventricle, but then back to the lungs. This happens because the pulmonary artery is connected to the left ventricle. The result is that highly-oxygenated blood keeps recycling through the lungs, while oxygen-depleted blood recycles through the body without going through the lungs to reoxygenate.
This condition develops during the fetal stage and must be treated promptly after birth if the newborn is to survive. The newborn can survive for a few days because the foramen ovale, a small hole in the septum that separates the two atria, is open, allowing some oxygenated blood to escape and mix into the blood that is being pumped throughout the body. However, the foramen ovale normally closes within a few days after birth.

Causes and symptoms

Transposition of the great arteries is a birth defect that occurs during fetal development. There is no identifiable disease or cause. The main symptom is a "blue" baby appearance, caused by a general lack of oxygen in the body's tissues.

Diagnosis

Diagnosis is made immediately after birth, when it is observed that the newborn is lacking oxygen. This is noted by the bluish color of the newborn, indicating cyanosis, a lack of oxygen. A definite diagnosis is made by x ray, electrocardiography (ECG), and echocardiography.

Treatment

The only treatment for this condition is prompt heart surgery shortly after birth. In surgery, the two great arteries are reconnected to their proper destination. This restores the normal blood flow pattern. The coronary arteries are also reconnected, so that they can supply blood to the heart itself. A catheter may be used to maintain or enlarge the opening between the two atria until surgery can be performed.

Prognosis

Left untreated, this disease is fatal within the first weeks of life.

Prevention

Because there is no identifiable cause, there is no way to prevent this condition.

Resources

Books

Alexander, R. W., R. C. Schlant, and V. Fuster, editors. The Heart. 9th ed. New York: McGraw-Hill, 1998.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

corrected transposition of the great vessels

(1) Anatomically corrected malposition of the great arteries—more popularly termed transposition of the great arteries.
(2) Physiologically corrected transposition of the great arteries.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
References in periodicals archive ?
Few of defects like atrial septal defect (ASD), coarctation of the aorta (CoA), Ebstein's anomaly, and congenitally corrected transposition of the great arteries (cCTGA) may be diagnosed for the first time in adult life.
Many hours later we received the worrying news that Poppy had TGA (Transposition of the Great Arteries), a serious but treatable heart condition.
The prenatal diagnostic conclusions were (1) evidence of transposition of the great arteries and (2) suspicion of type I esophageal atresia.
Jack, from Darlington, also had transposition of the great arteries which means the main heart valves are connected to the wrong places.
Laura said: "Florence was born with a condition called Transposition of the Great Arteries, or TGA, which means the main arteries in the heart - the aorta and the pulmonary artery - are connected to the opposite sides of the heart to where they should be.
What followed for Euphene and her husband Martin was every parent's nightmare as their daughter was diagnosed with transposition of the great arteries, where the pulmonary artery and the aorta arteries are mixed up.
The Wallsend youngster was diagnosed during pregnancy with congenitally corrected transposition of the great arteries (CCTGA) - a condition where the heart twists and ventricles are reversed.
At six days old, Laila had her first open heart surgery, after being diagnosed with three heart problems - pulmonary atresia, transposition of the great arteries and complete AVSD.
Her parents said: "During her 20-week scan our little heart warrior was diagnosed with transposition of the great arteries (TGA), a heart defect where the aorta is connected to the right ventricle, and the pulmonary artery is connected to the left ventricle -- the opposite of a normal heart's anatomy.
But when she was born on August 20, her mum Cassa learned she also had heart defects including transposition of the great arteries, two holes in her heart, a leaky valve, and other complications with her coronary arteries.
Coronary sinus ostial atresia with persistent left superior caval vein in a patient with congenitally corrected transposition of the great arteries. Cardiol Young 2018;28:498-9.
When Leo was born, he was diagnosed with a heart defect called Transposition of the Great Arteries (TGA), which meant the vessels carrying blood from his heart to his lungs was improperly connected.

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