What is a patent ductus arteriosus (PDA), and what are its symptoms?

A patent ductus arteriosus (PDA) occurs when the ductus arteriosus, a blood vessel that connects the pulmonary artery and the aorta during fetal development, fails to close after birth. This vessel is crucial for fetal circulation but normally closes within the first weeks of life, resulting in the separation of systemic and pulmonary circulation. When it remains open, it can create abnormal blood flow dynamics.

The characteristic symptom of a PDA is the presence of a continuous heart murmur, which can be detected during a physical examination. This murmur is due to the turbulent blood flow caused by the open ductus. Additionally, depending on the size of the PDA and the volume of blood shunted, infants may present with symptoms such as increased respiratory effort, tachypnea, difficulty feeding, and signs of heart failure.

In contrast, a patent ductus arteriosus does not typically present as a malformation leading to severe respiratory distress by itself; rather, it may contribute to respiratory challenges if left untreated. Therefore, while some conditions are more severe, the hallmark symptom of PDA is indeed the characteristic murmur.