The postnatal remaining open of the connection between the aorta and the pulmonary artery is referred to as patent ductus arteriosus . The earliest possible diagnosis and appropriate therapy prevent complications such as the death of the newborn in the worst case. If the closure is successful and complete, no further complications are to be expected.
What is patent ductus arteriosus?
The patent ductus arteriosus describes a heart defect in the newborn child. Before birth, there is a connection between the aorta and the pulmonary artery, which bypasses the pulmonary circulation of the unborn child (right-to-left shunt). Normally, a postnatal increase in oxygen in the blood causes the compound to contract and then reverse. See AbbreviationFinder for abbreviations related to Persistierender Ductus Arteriosus.
This should be done within the first three days after birth. This is not the case for about 30 percent of all infants born before the 31st week of pregnancy. If the duct remains open, the shunt reverses (left-right shunt). Patent ductus arteriosus is when the connection remains patent for more than three months after birth.
Patent ductus arteriosus accounts for five to ten percent of all congenital heart defects and often occurs in combination with other heart defects. Female newborns are affected two to three times more often than males.
Causes
The cause of the persistent ductus arteriosus is unclear. However, there is an increased incidence in premature babies, especially those with low birth weight, perinatal oxygen deficiency and births at high altitudes. Asphyxia, i.e. a threatening state of suffocation due to the drop in oxygen content with simultaneous retention of carbon dioxide, can also lead to the ductus remaining open.
Some children do not spontaneously adjust their breathing after birth to the changed circumstances, which is called respiratory adjustment disorder. Another cause can be chromosomal aberrations such as trisomy 21 or trisomy 18. In the course of a rubella embryopathy, in which the rubella virus is transmitted from the mother to the fetus, the ductus can also remain open. A familial occurrence is usually not the case.
Symptoms, Ailments & Signs
Symptoms depend on the size of the shunt. A small passage usually remains free of symptoms. If the gait is longer, a typical heart murmur can be heard on auscultation, which is most clearly in the upper left thorax. In addition, exertional dyspnea, tachycardia, difficulty breathing, cyanosis, prostration, and stunted growth, as well as apnea and bradycardia, occur in preterm infants.
In extreme cases, recurrent respiratory infections, congestion-related heart failure or, in older people, calcification of the duct and aneurysms can occur. Another complication is inflammation of the inner lining of the heart or the arteries, which can lead to septic embolism and lung abscesses.
A symptom-free course has a good prognosis, but carries the lifelong risk of endocarditis. A large duct can bring pulmonary hypertension, as well as an irreversible change in the pulmonary vessels.
Diagnosis & course of disease
There are several diagnostic options. Prenatal diagnosis is not possible because the ductus is open in all unborn babies. If a persistent ductus arteriosus is suspected, various procedures are used. When measuring the pulse, a pulsus celer et altus can indicate a large blood pressure amplitude. The typical, permanent heart murmurs can be clearly heard on auscultation.
Depending on the pressure and volume load, signs of cardiac hypertrophy are visible in the ECG. If the shunt is large, an enlargement of the left heart can also be seen on the chest X-ray. The echocardiogram and cardiac catheterization can demonstrate the ductus and associated abnormalities. Arteriovenous fistulas, a ventricular septal defect and peripheral pulmonary stenosis must be excluded in the differential diagnosis.
Complications
The ductus arteriosus is important before birth to connect the pulmonary circulation with the systemic circulation, because lung breathing is not yet possible. Only after birth does the ductus arteriosus close independently, creating a separate pulmonary circuit that is separate from the systemic circuit. Complications that can occur due to an untreated patent ductus arteriosus depend on the size of the ductus and the developmental stage of the newborn.
Minor connections between the two bloodstreams can be completely asymptomatic and do not require immediate treatment. With larger connections between the two blood vessels, blood flows from the aorta into the pulmonary artery, increasing pulmonary blood pressure. As a typical consequential damage, irreversible sclerotization of the pulmonary vessels can result, which makes the pulmonary high blood pressure irreversible, it is quasi fixed.
Due to the higher filling level of the left heart, further consequential damage is an enlargement (dilatation) of the left atrium and the left ventricle. In the long term, the changes in the heart lead to heart failure. In neonates with a relatively large patent ductus arteriosus, it is therefore advisable to separate the two blood circuits from one another by means of a small operation. As a rule, such interventions can even be carried out in a heart catheter laboratory, so that surgical care is not required.
When should you go to the doctor?
In any case, this disease requires a medical examination and further treatment. If left untreated, this disease usually leads to premature death or other life-threatening complications. A doctor should usually be consulted if the person concerned suffers from relatively loud and clearly audible heart murmurs.
This can also cause pain in the heart, with this pain being accompanied by severe breathing difficulties or a blue discoloration of the skin. Severe exhaustion or slowed development in children can also indicate this disease and should always be examined by a doctor. Furthermore, the disease leads to cardiac insufficiency, so that the performance of the patient decreases and the patient appears tired or sluggish.
The disease can be diagnosed by a general practitioner. However, further treatment is carried out by a specialist doctor. It cannot generally be predicted whether this will lead to a reduced life expectancy. The earlier the treatment is given, the higher the probability of a positive course of the disease.
Treatment & Therapy
Early diagnosis and therapy is essential, especially for premature babies and newborns with a low weight, since comorbidity and mortality are significantly higher in these babies due to haemodynamic instability. A patent ductus arteriosus should always be closed to minimize the risk of endocarditis.
The therapy of the patent ductus arteriosus takes place in different ways. It can be treated with prostaglandin synthesis inhibitors. Under no circumstances should these be administered during pregnancy, as the ductus must remain open prenatally. In the case of premature births, drug therapy is usually always used. There are special preparations for this that can be used for births before the 34th week of pregnancy.
A minimally invasive treatment method is the introduction of a spiral or an umbrella over cardiac catheters, which also occlude the ductus. In contrast to drug therapy, this method is more likely to be used in older children.
Surgical ligation of the ductus is possible. The mortality rate for this procedure is one percent in children and twelve percent in adults. Spontaneous closures of the ductus are possible. If closure is successful, the neonate has the same prognosis as the normal population. Another endocarditis prophylaxis is useful for six months to check the result of the treatment. After that, no more follow-up examinations are necessary.
Outlook & Forecast
The best prognosis is a patent ductus arteriosus if the duct can be closed. The problem is that this disorder shouldn’t occur in a newborn. Normally, this connection closes automatically after birth. In premature babies, however, this mechanism often fails. In rare cases, a minimally invasive ductus operation is necessary.
Having to operate on premature babies or newborns because of a persistent ductus arteriosus carries high risks. For this reason, pediatric cardiologists try to use a suitable medication to close the ductus arteriosus Botalli, which has not closed on its own, especially in the case of premature children. This preparation inhibits prostaglandin formation. Prostaglandin is a messenger substance that influences the immune system. When the prostaglandin level falls, the persistent ductus arteriosus often closes after all.
However, the administration of “indomethacin” is not possible or successful in every case. If this method fails or proves to be inapplicable, the unclosed connection between the aorta and the pulmonary artery in the affected infant can only be closed surgically. However, this only happens in older children by means of a heart catheter. If the duct seal is successful, the prospects of a long life are quite good.
The prognosis for a patent ductus arteriosus is significantly worse if it occurs together with other heart defects.
Prevention
A prophylaxis of the patent ductus arteriosus is not possible during pregnancy, since the patent ductus is essential for the development of the newborn. Various studies examined the effectiveness of individual drugs, with no significant difference being found.
Another study examined the association between phototherapy in preterm infants, which is also used for jaundice, and patent ductus arteriosus. However, no clear effectiveness could be determined. Since efficient prophylaxis is very difficult or impossible, timely diagnosis and intervention are all the more important for the health of the newborn.
Aftercare
Follow-up treatment is particularly necessary after surgical closure of the patent ductus arteriosus. After the operation, the patient is transferred to the intensive care unit for observation. If a cardiac catheter has been placed on a leg, it is important not to move it independently at the beginning. Heavy physical exertion should be avoided in the first week after the intervention.
In order to prevent an infestation with harmful bacteria, appropriate medication is administered intravenously as a preventive measure. The patient is also given heparin. As part of the aftercare, the patient must take clopidogrel for three months and acetylsalicylic acid (ASA) for six months.
These medicines are given to counteract the formation of blood clots on the materials used. Administered antibiotic agents protect the heart and blood vessels from inflammation. One day after the operation, x-rays are taken for control purposes. After about six months, an examination by swallowing echo takes place.
If any abnormalities become apparent during aftercare, these must be clarified by a doctor as quickly as possible. To ensure the success of the treatment, follow-up examinations should take place regularly. Only a few years later, if there are no symptoms, can these examinations be completely dispensed with. Due to a lack of long-term experience, it cannot be said with certainty whether this is also possible in children who have been treated with a cardiac catheter.
You can do that yourself
Patent ductus arteriosus in newborns can be treated with precise drug dosing or surgery. The parents of the affected child should follow the doctor’s instructions exactly in everyday life. Infections and other illnesses should be avoided if possible, especially in the initial period after the birth.
When the ductus arteriosus is diagnosed or suspected, it is very important to pay attention to the newborn’s heart murmurs. Along with fever or other symptoms, such observations point to the medical problems. Blood pressure also plays a role. Regular follow-up checks are essential for parents. This is the only way to check whether the child is healthy and can grow up normally. The dates for the examinations must be strictly observed.
If an operation is performed, further doctor’s appointments follow. At the same time, parents can carefully watch their child. In this way, they can identify any problems such as subsequent injuries, inflammation or a curvature of the back in good time. In such cases, you should not wait for the next examination appointment, but see a doctor as soon as possible. It is also important that the newborn is not exposed to too much strain.
