What is Patent Ductus Arteriosus?
- Ductus arteriosus is an important blood vessel in fetus which connect two major arteries (aorta and pulmonary artery) that go from the heart. It is supposed to be closed after the baby is born.
- Patent ductus arteriosus (PDA) is a medical condition in which the ductus arteriosus fails to close after birth.
- Before birth, the blood of fetus doesn’t need to go to lungs for oxygenation. Thus, ductus arteriosus allows blood to detour away from lungs (allow blood to pass from pulmonary artery to aorta) before birth and baby receives oxygen form mother’s circulation. However, after birth, the blood needs to go to lungs for oxygenation and this hole is supposed to close. If the ductus arteriosus remains open even after birth, the blood may skip this necessary step of circulation leading to mixing of oxygen poor blood from pulmonary artery with oxygen-rich blood from aorta.
- Every baby is born with ductus arteriosus. After birth, it usually gets narrowed and closes within first few days except in patent ductus arteriosus.
- PDA may be small or large. A small PDA often doesn’t cause problems, no symptoms are seen and may seal up on their own by the time child is one year old. Large patent ductus arteriosus may cause heart complications and require treatment.
Symptoms of Patent Ductus Arteriosus
Some common signs and symptoms are:
- Shortness of breath (dyspnea)
- Persistent fast breathing or breathlessness
- Rapid heart rate
- Continuous machine-like heart murmur
- Easy tiring
- Poor eating which may lead to poor growth
- Tahycardia
Cause and Risk factors of Patent Ductus arterioles
- There is no clear cause. Genetic factors may be involved.
- Some risk factors associated are:
- Premature birth.
- Family history and other genetic condition such as Down syndrome.
- Rubella infection during pregnancy in mother.
- It is more common in girls than boys.
- More common in neonates with respiratory distress syndrome.
Diagnosis
- A doctor will usually diagnose PDA after listening to child’s heart. In most cases of PDA, heart murmur (an extra or unusual sound in the heartbeat) occur which a doctor can hear through a stethoscope.
- A chest X-ray may also be necessary to see overall heart size and appearance of blood flow to lungs.
- Echocardiogram and associated Doppler studies may be useful.
- Electrocardiogram may not be particularly useful.
Complications
Large patent ductus arteriosus may cause following complications:
- It can cause heart to enlarge and weaken leading to heart failure.
- It increases risk of infectious endocarditis (inflammation of inner lining of heart).
- Normally the heart’s left side only pumps blood to the body, and the right side only pumps blood to the lungs. In a child with PDA, extra blood gets pumped from the body artery (aorta) into the lung (pulmonary) arteries. Too much blood circulating through heart’s main arteries may cause pulmonary hypertension.
Treatment
- In case of small PDA, treatment is not required. Regular monitoring of PDA should be done as the baby grows. If it doesn’t close on its own, medication or surgical treatment may be required.
- NSAIDs such as indomethacin or special from of ibuprofen are used to close the opening in PDA. These are effective in newborn infants.
- Catheter based procedures are recommended in infant or child with small PDA.
- Surgical treatment is preferred in children who are 6 months or older. In surgical treatment, ductus arteriosus is closed by ligation, either manually tied shot or with intravascular coils or plugs.
Prevention
- There is no sure way to prevent PDA. However, some basics which can help to have healthy pregnancy are:
- Seeking early prenatal care, even before pregnancy.
- Eating healthy diet.
- Doing exercise regularly.
- Avoiding alcohol, cigarettes and other habit-forming drugs during pregnancy.
- Avoiding infection by proper vaccination.
- Controlling diabetes.
- Consulting genetic counselor before pregnancy, if there is family history of genetic defects.
References