Congenital Heart Disease: What Problems May Occur With Levo-Transposition Of The Great Arteries?

Levo-transposition of the great arteries, also known as congenitally corrected transposition, is a very rare congenital heart disease that affects only approximately 0.5 to one percent of patients with heart defects. What should you know about it?

What is levo-transposition of the great arteries?

Fortunately, levo-transposition of the great arteries is less dangerous than its counterpart, dextro-transposition of the great arteries, because it is a double-reversal, which means that the body continues to receive oxygen-rich blood and the lungs continue to receive oxygen-poor blood.

What are the symptoms of levo-transposition of the great arteries?

Since the blood circulation is adequate, many patients with this disease don’t experience any symptoms for a very long time and the disease can go undiagnosed into adulthood. Some people with the disease may have other congenital heart defects, which can lead to a number of symptoms. On other hand, some patients with levo-transposition of the great arteries will develop symptoms as a result of the fact that the two ventricles are meant to handle different types of blood pressure.

Therefore, the right ventricle may eventually become enlarged due to high blood pressure, leading to symptoms such as dyspnea (trouble breathing) or fatigue (tiredness). Some patients may also experience mild cyanosis (a lack of oxygen in the body), leading to a bluish tint. Congestive heart failure, heart murmurs and arrhythmia (abnormal heart rhythms) may also develop later on in adulthood.

What are the risk factors associated with levo-transposition of the great arteries?

While the cause of most congenital heart diseases, including levo-transposition of the great arteries, is not known, studies have found several risk factors. These factors are largely maternity-related, including:

• A viral infection during pregnancy
• The mother drinks alcohol or smokes during pregnancy
• A mother with poorly-controlled diabetes while pregnant

How is levo-transposition of the great arteries diagnosed?

Levo-transposition of the great arteries may be diagnosed when the baby is still a fetus through an ultrasound at 18 weeks. In many mild cases, levo-transposition of the great arteries is diagnosed later in adulthood when the patient is being treated for or being diagnosed with another condition. The different tests that can be used to diagnose levo-transposition of the great arteries are:

• An echocardiogram, a test in which sound waves are used to develop an image of the heart.
• Chest X-ray to visualize chest structures.
• Cardiac MRI, which uses magnetic resonance technology to create a detailed, three-dimensional image of the heart.
• Cardiac catheterization, in which a thin flexible tube is inserted into the vein or the artery.

Usually for patients with levo-transposition of the great arteries, either an echocardiogram or cardiac MRI is ordered to diagnose the disease.

How is levo-transposition of the great arteries treated?

Children diagnosed with levo-transposition of the great arteries before they are born or right after they are born will be closely monitored for development of any symptoms or complications. If the baby doesn't display any symptoms, they can go home but they will continue to be frequently monitored for any changes.

Many patients with simple levo-transposition of the great arteries won't be diagnosed until later on in life and their treatment will depend on the severity of their condition and symptoms. These patients will be thoroughly examined using a number of tests such as echocardiograms and electrocardiograms. Generally, patients with levo-transposition of the great arteries but no accompanying heart problems or symptoms may not need surgery.

In some cases, surgeons have to perform an operation known as a double-switch operation, which helps restore normal blood flow through the ventricle or the heart. During a double-switch operation, surgeons can help redirect the blood flow from one part of the heart to another. This surgery allows blood to flow to the correct place and the left ventricle goes back to pumping blood to the rest of the body.

The timing of this surgery is vital as it needs to be done before the left ventricle's muscle becomes too weak. In some instances, the muscle will have to be retrained so it's strong enough to pump blood, which might require additional surgery before the double switch surgery. Some patients may need to undergo repeat procedures, and in rare cases, some may need a heart transplant.

What complications are associated with levo-transposition of the great arteries?

As patients get older, several complications may result from levo-transposition of the great arteries:

• Problems with weakness of heart muscle.
• Problems with tricuspid valve leakage.
• Heart rhythm issues, particularly slow heart rhythms, which can cause cause fainting or fatigue. One type of slow rhythm, known as a complete heart block, is quite common in patients with levo-transposition of the great arteries.
• The right ventricle of the heart can become weak, leading to congestive heart failure.

What is the outlook for patients with levo-transposition of the great arteries?

Fortunately, due to enormous advances in medicine, most children born with levo-transposition of the great arteries live healthy and productive lives, with outcomes being even better for patients who don’t have extra heart defects.