Transposition of the Great Arteries

Heart With Transposition of the Great Arteries

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The aorta normally originates from the left ventricle and is the main artery that carries oxygen-rich blood to the body. The pulmonary artery is the main artery that carries deoxygenated blood from the right ventricle to the lungs. In a case of transposition of the great arteries, these two main arteries are inverted. In other words, the aorta originates from the right ventricle and the pulmonary artery originates from the left ventricle.

Therefore, the pulmonary artery carries oxygenated blood from the left ventricle back to the lungs and the aorta carries deoxygenated blood from the right ventricle to the body causing the baby to appear cyanotic, or blue. Without a way for the oxygenated blood of the left ventricle to reach the aorta and, in turn, the rest of the body, the child will not survive. Often, an associated ASD or VSD is present allowing blood to flow between the right and left sides of the heart.

In other cases, a PDA is present allowing blood flow between the pulmonary artery and aorta. Early surgical correction is essential. The procedure, known as the Arterial Switch operation, involves transposing the two great arteries as well as the coronary arteries (the small blood vessels that supply oxygenated blood to the heart muscle itself).


What Is Normal Cardiac Anatomy?

When your child has a congenital heart defect, there's usually something wrong with the structure of his or her heart's structure.

 
Learn More About Normal Cardiac Anatomy

Heart With Normal Cardiac Anatomy

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When your child has a congenital heart defect, there's usually something wrong with the structure of his or her heart's structure.

The heart is composed of four chambers. The two upper chambers, known as atria, collect blood as it flows back to the heart. The two lower chambers, known as ventricles, pump blood with each heartbeat to the two main arteries (the pulmonary artery and the aorta). The septum is the wall that divides the heart into right and left sides. The atrial septum separates the right and left atria; likewise, the ventricular septum separates the two ventricles.

There are four valves that control the flow of blood through the heart. These flap-like structures allow blood to flow in only one direction. The tricuspid and mitral valves, also known as the atrioventricular valves, separate the upper and lower chambers of the heart. The aortic and pulmonary valves, also known as the arterial valves, separate the ventricles from the main arteries. Oxygen-depleted blood returns from the body and drains into the right atrium via the superior and inferior vena cavas. The blood in the right atrium then passes through the tricuspid valve and enters the right ventricle.

Next, the blood passes through the pulmonary valve, enters the pulmonary artery, and travels to the lungs where it is replenished with oxygen. The oxygen-rich blood returns to the heart via the pulmonary veins, draining into the left atrium. The blood in the left atrium passes through the bicuspid, or mitral, valve and enters the left ventricle.

Finally, the oxygen-rich blood flows through the aortic valve into the aorta and out to the rest of the body.

A to Z: Atrial Flutter

A to Z: Atrial Flutter

Atrial (AY-tree-ul) flutter is an abnormal heart rhythm (arrhythmia) that causes the heart to beat too quickly.

More to Know

The electrical impulse that keeps the heart beating normally begins at a group of cells called the sinus node, located in the right atrium (one of the heart's upper chambers). With atrial flutter, however, the electrical impulse begins in a circuit that moves throughout the right atrium and causes the heart to beat rapidly and abnormally.

A rapid heartbeat can stress the heart and cause chest pain, palpitations, shortness of breath, fatigue, and low blood pressure.

Atrial flutter is often caused by damage to the heart or by congenital (present at birth) heart defects. Other causes include certain medications, viral infections, and metabolic disorders. In some cases, it happens for no apparent reason. It can also come and go.

A rapid heartbeat can increase the risk of stroke or heart disease, so should be treated. Treating the cause of atrial flutter can usually restore a normal heart rate. Medications can also help slow the heart or thin the blood to reduce the risk of stroke.

Keep in Mind

Though it can be serious, if atrial flutter is treated properly, most people can live perfectly normal lives, although some may have a relapse of the condition from time to time.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.

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Date reviewed: September 26, 2016