Truncus arteriosus is a rare congenital heart defect in which a single large blood vessel leads away from the heart rather than two separate vessels.
Normally, a person’s blood flow follows a certain path – from the body to the heart, and then to the lungs before returning to the heart to be pumped back into the body. In patients with truncus arteriosus, this does not happen. When there is only one vessel leading away from the heart, the blood does not have a specific path to follow to reach the lungs and retrieve oxygen.
Additionally, there is often a hole between the two lower chambers of the heart. This condition is called a ventricular septal defect. The truncal valve, which controls blood flow from the ventricles to the single vessel, may also be defective.
All three occur during fetal development when the baby’s heart is forming, but the exact reason for this is unknown. Patients with truncus arteriosus experience severe circulatory issues. Left untreated, the defect can prove fatal.
Indications of truncus arteriosus are typically visible within a child’s first few days of life.
Truncus arteriosus occurs when a baby’s heart is developing and is present at birth (congenital). In most cases, the cause is unknown. Some congenital heart defects that lead to truncus arteriosis may have a genetic link to certain families. Other times, it occurs by chance, with no clear reason.
Other factors that can cause truncus arteriosus include the mother contracting rubella or any other viral sickness during pregnancy. When a pregnant mother consumes alcohol in excessive amounts, it can lead to truncus arteriosus. If left untreated during pregnancy, the mother’s out of control diabetes can lead to this congenital heart defect.
If either parent has a history of congenital heart disease, the likelihood of the baby developing truncus arteriosus increases.
Infants born with truncus arteriosus will require surgery to correct the defect. There might be a need for multiple procedures as the child grows and can include closing the ventricular septal defect, implanting a tube that connects the right ventricle to the upper pulmonary artery, separating the pulmonary artery from the large vessel, and reconstruction to create a complete aorta.
Prior to surgery, diuretics and ionotropic agents may be given. These will help increase urination to prevent water retention and strengthen heart contractions, respectively. Lifelong follow-up care will then be needed to monitor heart health.
Congenital heart defects like truncus arteriosus can’t be prevented. However, if you or your spouse have a family history of heart defects, or you already have a child with a congenital heart defect, you should consider seeing a genetic counselor. You should also see a cardiologist experienced in congenital heart defects prior to becoming pregnant again.
There are steps you can take prior to becoming pregnant to help ensure a healthy baby. Make sure your rubella and other vaccinations are up to date and avoid dangerous medications. If you take folic acid, it can help prevent birth defects, such as truncus arteriosus. In order to be effective, 400 micrograms is the recommended daily dosage.
If you have diabetes, do everything you can to keep it under control, including taking your medication and regularly measuring your sugar levels. You should always talk to your doctor about any pregnancy risks that can occur as a result of your diabetes, so you can manage the disease during your pregnancy and protect your baby. If you are uncomfortable with your risk factors, the only guaranteed prevention is to forego pregnancy.