Ductus arteriosus is a channel between two major arteries during the fetal life namely the aorta and the pulmonary artery. The reason for its presence is that, during fetal life, the lungs would not be active and therefore will lie redundant till the fetus comes out from the mothers womb. Thus, the blood circulating towards the lungs will be shunted back into the main arterial system, which is the aorta, through the ductus arteriosus. But, when the baby is born, the lungs should receive its blood supply and therefore will not require the services of this channel further. Thus, naturally, the vessel walls of the ductus arteriosus will go into a spasm and would become obliterated thus closing the channel.
What is patent ductus arteriosus?
But, in certain instances, the ductus arteriosus can remain intact, although it is supposed to close itself within 2 – 3 days or else in several weeks in premature infants. When this channel persists it is referred to as patent ductus arteriosus or persistent ductus arteriosus (PDA).
The condition can remain dormant for many years when the channel remains small although if it is large enough the symptoms may be apparent early in infancy or else in the childhood.
Why does PDA cause symptoms?
Being a channel between the high pressure aortic artery and the relatively low pressured pulmonary artery, there will be a blood flow from the aorta towards the pulmonary artery. This means that, more blood will be shunted towards the lungs and less towards rest of the body. As the lungs are not built to handle such huge volume of blood it can become congested and develop a condition known as pulmonary edema and pulmonary hypertension. At the same time, more blood would be returning to the left atrium which is not catered to handle such volumes and therefore could lead to a failure. Furthermore, reduced circulating blood volume will lead to many other manifestations as well.
What are the possible symptoms of a patent ductus arteriosus?
As described earlier, the congestion in the lungs can lead to symptoms such as breathlessness, excessive tiredness or fast breathing with play or with cry, sweating, excessive crying, poor feeding, poor weight gain…etc. At the same time, congestion may lead to frequent lung infections as well.
When inspected closely, these infants or children may have a fast heart beat and will show signs of poor circulation through dusky or bluish discoloration to the skin tone. At the same time, a characteristic murmur can also be heard by a health care professional who examines the child using a stethoscope while they will also be able to recognize a characteristic bounding pulse in certain individuals.
If the PDA persists and leads to congestion of the heart, there is a possibility of developing signs of heart failure in the long run.
Although the above symptoms are the main manifestations of a PDA, it may sometimes remain silent till adult life and could manifest with signs of heart failure or could be detected as an incidental finding.