What is a common consequence of untreated PDA in infants?

The most common consequence of untreated patent ductus arteriosus (PDA) in infants is heart failure. In a healthy, term newborn, the ductus arteriosus, a fetal blood vessel connecting the pulmonary artery to the aorta, is supposed to close shortly after birth. If it remains open (patent), it can lead to an abnormal flow of blood, where oxygen-rich blood from the aorta recirculates back into the pulmonary arteries instead of flowing into the systemic circulation.

This results in increased blood flow to the lungs, causing pulmonary congestion and elevated pressures within the pulmonary circulation. Over time, this volume overload on the heart can lead to left-sided heart strain and ultimately result in heart failure, characterized by signs such as tachycardia, poor feeding, difficulty breathing, and failure to thrive in the infant.

While other complications, such as stroke or right heart failure, can occur in specific contexts or due to other underlying conditions, they are not the most immediate or common consequence of an untreated PDA. Ventricular tachycardia is also less likely to arise solely from PDA and is associated with different cardiac conditions. Thus, heart failure is recognized as the primary and most common consequence of untreated PDA in infants