Patent ductus arteriosus
Patent ductus arteriosus or patent ductus arteriosus is a congenital heart defect, a type of congenital disorder in which the ductus arteriosus does not close. The ductus arteriosus connects the aorta and the pulmonary artery and closes after birth in healthy babies. This failure to close can result in blood accumulating in the lungs.
Definition & Facts
While the ductus arteriosus is patent or open while the baby is in the womb, it normally closes within 15 hours after birth. It may permanently close after two to three weeks in healthy infants. In patients with patent ductus arteriosus, the ductus does not close, causing blood flow to be insufficiently oxygenated and to possibly flow in the opposite direction.
This condition can cause the cardiac muscle to weaken. Eventually it can lead to such complications as heart failure, if not addressed. A pediatrician can detect the possibility of patent ductus arteriosus by listening to the heartbeat of the child; patent ductus arteriosus creates a heart murmur which doctors will be able to hear using their stethoscope.
Patent ductus arteriosus may be asymptomatic and it may also spontaneously resolve. By contrast, if the patent ductus arteriosus is large, symptoms can be life-threatening.
Symptoms & Complaints
- Sweating while eating or crying
- Poor feeding that causes poor growth
- Tiring easily
- Breathlessness or consistent rapid breathing
- Fast heart rate
Patent ductus arteriosus can cause an excessive amount of blood to circulate around the infant's heart and lungs. If left untreated, the baby's lungs will likely experience high blood pressure, known as pulmonary hypertension. At the same time, the heart of the baby could become enlarged (cardiomegaly) and become weakened.
The mechanism by which the ductus arteriosus fails to close involves the metabolism of prostaglandin. Prostaglandin prevents the ductus from closing in the uterus, which is necessary for the fetus. It is believed that the immaturity of the lungs in premature babies may prevent prostaglandin from being properly metabolized which keeps prostaglandin levels high upon birth and thereby prevents closure. Improper metabolism of prostaglandin can also be linked to acute kidney failure and respiratory disorders.
Patent ductus arteriosus is more common among females than males. Babies who are born at higher altitudes of over 10,000 feet are also at greater risk of having this problem. Infants whose parents have a history of patent ductus arteriosus are more likely to be born with the problem as well.
Babies born with Down syndrome are more likely to have patent ductus arteriosus. The presence of other congenital heart defects like pulmonary stenosis is common among newborns with patent ductus arteriosus.
Diagnosis & Tests
Doctors have a number of tests at their disposal when they suspect there is a heart defect such as patent ductus arteriosus. These include the following:
- Chest X-ray - Doctors can use the X-ray to better study the baby's lung and heart conditions.
- Echocardiogram - Using sound waves to create heart images, doctors can determine if the heart is too large and how it is pumping blood.
- Electrocardiogram (ECG) - The ECG records the heart's electrical activity.
- Cardiac catheterization - Such a test can be utilized to study other kinds of congenital heart defects a doctor may detect on an ECG.
Treatment & Therapy
There are several treatments for patients who suffer from a patent ductus arteriosus. The appropriate ones depends on how old the patient being treated is. These options include:
- Watchful waiting - Premature babies' hearts can be monitored to see if the ductus will close up on its own. With smaller patent ductus arteriosus, it might be that monitoring the condition is all the patient requires.
- Medicines - Premature babies can take nonsteroidal anti-inflammatory drugs like ibuprofen or indometacin in order to close up the patent ductus arteriosus. They will not work on adults, children, or full term infants.
- Open heart surgery - When medications do not solve the problem and the complications from the patent ductus arteriosus are serious, a doctor might suggest open heart surgery. This requires a small incision between the ribs of the child to get to the heart and fix the open duct with clips or stitches. Some adults may also need this treatment if the patent ductus arteriosus is causing life-threatening conditions like congestive heart failure.
- Catheter procedures - When a baby reaches a certain stage of development, doctors can utilize catheter procedures to fix the patent ductus arteriosus. This works well for children and adults. The doctor inserts a coil or plug up through the catheter and closes the ductus arteriosus.
Prevention & Prophylaxis
For those children who undergo a catheter repair operation, the doctor will normally recommend an extensive course of antibiotics. They may need to take these for a full six month term following the surgery. This is especially the case if the repair does not correct all of the damage.