Arterial trunk (truncus arteriosus)

2021-08-09 11:55 AM

If left untreated, the common artery is often fatal within the first year of life. Surgery to repair the heart and blood vessels is generally successful, especially if the repair occurs before the baby is 2 months old.

Define

The arterial trunk is a rare heart defect at birth (congenital). If there is a common artery, one large tube, instead of two separate tubes, leads out of the heart. In addition, the two lower chambers of the heart are partially missing a septum. The result of the common trunk artery is that oxygen-poor blood (going to the lungs) and oxygen-rich blood (going to the rest of the body) mix. This creates serious circulation problems.

If left untreated, the common artery is often fatal within the first year of life. Surgery to repair the heart and blood vessels is generally successful, especially if the repair occurs before the baby is 2 months old.

Symptoms

Signs and symptoms of the common trunk artery usually develop during the first few weeks postpartum. These include

Cyanosis skin.

Eat poorly.

Excessive sleepiness.

Slow growth.

Shortness of breath.

Breathe fast.

Irregular heartbeat (arrhythmia).

Excessive sweating (diaphoresis).

Seek medical treatment if you notice any of the following problems

Purple skin.

Eat poorly.

Slow growth.

Excessive sleepiness.

Sweating too much.

Some signs of the arterial trunk may indicate a problem that requires urgent care.

If your baby experiences any of the following signs and symptoms, seek emergency medical attention

Breathe shallowly or quickly.

The pale skin is worse.

Loss of consciousness.

Causes

Arterial trunks occur during fetal growth while the baby's heart is developing. In most cases, the cause is unknown. An overview of cardiac structure and function is helpful in understanding common trunk artery defects.

Heart

The heart has four pumping chambers that circulate blood. The valves control blood flow, opening and closing to ensure blood flow in a single direction.

Four chambers of the heart

Right atrium. The right upper chamber receives oxygen-poor blood from the body and delivers it to the right ventricle.

Right ventricle. The lower right chamber, which pumps blood through a large tube called the pulmonary artery, and into the lungs, where the blood is supplied with oxygen.

Left atrium. The upper left side receives oxygen-rich blood from the lungs and delivers it to the left ventricle.
 
Left ventricle. The lower left chamber, which pumps oxygen-rich blood through a large tube called the aorta, to the rest of the body.

Normal heart development

The formation of the fetal heart is a complex process. At a certain point, all fetuses have a single large vessel (arterial trunk) that originates from the heart. During normal heart development, however, this single large artery divides into two parts. The lower component is the aorta, which is attached to the left ventricle. The other part becomes the lower part of the pulmonary artery, which is attached to the right ventricle.

Also during this process, the ventricles develop into two chambers, separated by a wall (septum).

Arterial trunks in neonates

In infants born with a common trunk, the large single tube never completes division into two separate vessels. And the wall separating the two ventricles never closes completely, resulting in a large hole between the two chambers (interventricular septal defect).

The aortic trunk in the neonate is also called a continuous arterial trunk because the early stages of cardiac development persist until birth.

In addition to the major trunk defects, the valves that control blood flow from the ventricles to the common trunk often fail, allowing blood to flow back into the heart.

Risk factors

While the exact cause of congenital heart defects, such as common trunk arteries, is unknown, certain factors may increase the risk of a baby being born with heart disease. These include:

Viral diseases during pregnancy. If a woman contracts rubella (German measles) or another virus during early pregnancy, the risk of congenital heart defects in her baby increases.

Gestational diabetes is difficult to control. Unmanaged diabetes can increase the risk of birth defects, including heart defects.

Certain medications are used during pregnancy. Many drugs are not recommended for use during pregnancy because of the potential risk to the fetus.

Certain chromosomal disorders. Children with Down syndrome, DiGeorge syndrome, or velocardiofacial are at increased risk of the common arterial trunks. These problems are caused by one or more chromosomal defects.

Complications

Abnormal structures of the heart - trunk arteries cause serious problems with blood circulation. Because the ventricles are not separated and all the blood passes through the single tube, the oxygen-rich blood, and the oxygen-poor blood mix together - resulting in the blood not carrying enough oxygen. The blood flows mix from the single great tube to the lungs, arteries of the heart, and the rest of the body.

If there is a common arterial trunk, the abnormal circulation of blood often leads to

Respiratory problem. Abnormal distribution of excessive blood flows into the lungs. Too much fluid in the lungs makes it difficult to breathe.

Pulmonary arterial hypertension. Increased blood flow to the lungs narrows the pulmonary blood vessels p, increases pressure, and makes it increasingly difficult for the heart to pump blood into the lungs.

Cardiomegaly (cardiomegaly). With pulmonary hypertension and increased blood flow through the heart, the heart works harder than usual, causing dilation. The heart gradually dilates and weakens.

Heart failure. Increased workload and poor oxygen delivery also cause heart failure. These factors can contribute to heart failure.

Subsequent complications

Even with successful cardiac repair at an early stage, other complications related to the common trunk can occur later in life:

Progressive pulmonary hypertension.

Heart valve opening.

Heart rhythm disturbances.

Common signs and symptoms of this complication include shortness of breath, dizziness, fatigue, and a feeling of a fast, fluttering heartbeat (palpitations).

Arterial trunk in adults

In rare cases, people with a common artery can survive without cardiac surgical repair and live into adulthood. However, people with this condition will almost certainly develop heart failure and Eisenmenger syndrome. This syndrome is caused by permanent damage to the lungs from pulmonary hypertension. A heart-lung transplant is often the only treatment option.

Tests and diagnostics

In order for pediatric cardiologists to check your heart condition and make a diagnosis, they will recommend one or more tests:

Echocardiography

An echocardiogram shows the structure and function of the heart. With this test, a probe emits sound waves and records the echoes as they reflect structures. The computer converts the sound into a moving image on the screen.

With the common trunk, echocardiography shows a single large duct from the heart, a perforation in the wall between the left and right ventricles, and sometimes valve abnormalities between the great ducts and the ventricles.

Since an echocardiogram shows blood flow, it can also show blood moving back and forth between the two ventricles and the amount of blood flowing into the lungs. The amount of blood can indicate the risk of hypertension in the lungs.

X-ray

X-rays use electromagnetic radiation to create images of organ structures and structures. X-rays can show the size of the heart, abnormalities in the lungs, and fluid in the lungs.

Treatments and drugs

Surgery can often repair the common trunk of the artery. Sometimes multiple procedures or surgeries are needed. Before undergoing surgery, breastfeeding may be more frequent to ensure proper nutrition and medication to improve heart and lung function.

Medicine

Medications that may be prescribed before surgery may include:

Digoxin (Lanoxin). This drug, also called digitalis, increases the strength of heart muscle contractions.

Diuretic. Diuretics increase the frequency and volume of urine, preventing fluid stagnation in the body - a common effect of heart failure.

Surgery

Most infants with common arterial trunk surgery are within the first two months of life. The exact procedure will depend on the specific condition. Most commonly, the surgeon will:

Close the hole between the two ventricles.

Separate the upper part of the pulmonary artery from the single great duct.

Ducts and valves connect the right ventricle to the upper part of the pulmonary artery - creating a new artery.

Rebuild the great duct and aorta to create a new aorta.

Implant a new valve separating the left ventricle and aorta if necessary.

After surgery, lifelong follow-up care is needed with a cardiologist to monitor heart health. Cardiologists may recommend activity limits, especially intensely competitive sports. Antibiotics are needed before dental and other surgical procedures to prevent infection.

Because the ducts do not grow, one or more surgeries to replace the ducts are often needed as the baby grows. The newer surgical procedure uses a cardiac catheter inserted into a blood vessel in the leg, which is then threaded up to the heart to replace the ducts without the need for traditional heart surgery. In addition, cardiac catheterization with a balloon can be used to open blocked or narrowed arteries, possibly delaying the need for further surgery.

Pregnancy

Women who have had surgery to repair the common trunk artery should be evaluated by a cardiologist with expertise in congenital heart defects and an obstetrician. Depending on how much lung damage occurred before surgery, pregnancy may or may not be recommended. In addition, some medications used for heart disease can be harmful to an unborn baby.

Coping and supporting

Caring for a baby with a serious heart problem, such as a common artery, can be challenging. Here are some strategies that can help make it easier:

Seek support. Ask for help from family members and friends.

Record your baby's health history. Write down the diagnosis, medications, surgery and other procedures, the dates performed, the pediatric cardiologist, and any other important information about the baby's care. It is also helpful to include a report from the child's surgeon on file. This information will help recall the care your child has received, and it will be useful to other doctors who need to review health history.

Talk about concerns. There may be concerns about the risks of vigorous activity, even after corrective surgery. Talk to your cardiologist about safe activities. If limited, encourage activities other than focusing on what cannot be done. If you have other health concerns, discuss them with your doctor or pediatric cardiologist.

Prevention

In most cases, a congenital heart defect, such as a common trunk artery, cannot be prevented. If there is a family history of heart defects or if you have had a child with a congenital heart defect, you and your partner may consider talking to a genetic counselor and a cardiologist experienced in these conditions. congenital heart defects before making a decision about pregnancy.

If you're thinking about becoming pregnant, there are a few steps you can take to help ensure a healthy baby, including:

Vaccinated before pregnancy. Some viruses, such as rubella (German measles), can be very harmful during pregnancy, so it's important to make sure your shots are up to date before you get pregnant.

Avoid dangerous drugs. Check with your doctor before taking any medication if you are pregnant or thinking about becoming pregnant. Many medications are not recommended for use during pregnancy.

Folic acid. One of the steps you can take to help prevent birth defects, including spine, brain, and possibly heart defects, is to take 400 micrograms of folic acid a day.

Control diabetes. If you're a woman with diabetes, talk to your doctor about the pregnancy risks associated with diabetes and how best to manage the disease during pregnancy.