Truncus arteriosus belongs to a category of birth defects known as conotruncal heart defects, or outflow tract defects.
What it is
Truncus arteriosus occurs when the aorta and the pulmonary artery, which should be separate, are together as one blood vessel. This causes both low-oxygen and oxygen-rich blood to be sent to the body and lungs. Normally oxygen-rich blood would be sent to feed the tissues and low-oxygen would go to the lungs to be re-oxygenated. Without the proper blood going to the appropriate place, the body does not receive the nutrients that arrive via the oxygen-rich blood. When this defect is present, the two lower chambers of the heart are also missing a portion of the wall that should divide them.
Truncus arteriosus is commonly found in conjunction with ventricular septal defect (VSD).
Symptoms of truncus arteriosus are often apparent in the first few weeks of the baby’s life, including:
- Blue coloring of the skin, or cyanosis
- Poor feeding
- Poor growth
- Excessive sleepiness
- Shortness of breath, or dyspnea
- Rapid breathing, or tachypnea
- Irregular heartbeats, or arrhythmia
- Excessive sweating, or diaphoresis
Anti-depressants: Several studies have linked maternal use of anti-depressants to a doubled risk of the infant being born with conotruncal heart defects, such as truncus arteriosus. This applies to infants whose mothers took certain anti-depressants just before or during pregnancy. For more information, click any of the drug names below. Anti-depressants include:
If left untreated, most babies will not survive beyond the first year. However, surgery to repair the heart and blood vessels is usually successful.
Prior to surgery, a baby with truncus arteriosus may be prescribed medicines:
- Digoxin – increases the strength of the heart muscle contractions
- Diuretics – increase the frequency and volume of urination, preventing fluid from collecting in the body, which is a common effect of heart failure
Open-heart surgery is usually required to correct this issue, preferably within the first two months of the baby’s life. The exact method of the procedure depends on the individual situation. During the operation, a surgeon will install a prosthetic tube that will direct blood flow correctly and seal the hole between the two ventricles. This tube usually needs replaced once or twice as the child grows. It may be recommended later in life that women who were born with truncus arteriosus not risk getting pregnant. Children with this defect will require lifelong follow-up care with a heart doctor.