What condition can result from untreated patent ductus arteriosus in infants?

Patent ductus arteriosus (PDA) is a condition where the ductus arteriosus, a blood vessel that connects the pulmonary artery to the aorta, fails to close after birth. This vessel normally closes shortly after birth to redirect blood flow to the lungs for oxygenation instead of allowing it to flow directly into the aorta.

When PDA remains open (patent), it can cause an abnormal amount of blood to flow into the lungs, leading to pulmonary overcirculation. This increased blood flow can lead to several complications, with heart failure being one of the most significant outcomes when left untreated. In infants, the heart might struggle to cope with the additional workload, eventually leading to symptoms of heart failure, such as difficulty feeding, poor weight gain, rapid breathing, and failure to thrive.

Other conditions mentioned, such as myocardial infarction, asthma, and diabetes, are not directly related to untreated PDA. Myocardial infarction is typically associated with coronary artery disease, asthma relates to respiratory issues rather than structural heart problems, and diabetes involves metabolic processes unrelated to the structural circulatory changes caused by PDA. Thus, heart failure is the most relevant consequence of untreated patent ductus arteriosus in infants.