What complication can arise from an untreated patent ductus arteriosus?

An untreated patent ductus arteriosus (PDA) can lead to hypertension, specifically pulmonary hypertension. The ductus arteriosus is a blood vessel that should close shortly after birth, allowing blood to flow normally between the aorta and pulmonary arteries. If it remains patent, it can cause increased blood flow to the lungs, leading to pulmonary overcirculation.

As a result of this increased blood volume in the pulmonary circulation, the blood vessels in the lungs must work harder, which can lead to elevated pressures within these vessels. Over time, this can cause changes in lung vasculature and ultimately result in pulmonary hypertension. This condition can contribute to further cardiac complications and should be monitored and treated to prevent progressive heart failure and other serious issues.

The other options, while related to cardiovascular concerns, do not directly arise as complications from an untreated PDA in the same manner that pulmonary hypertension does. Atrial fibrillation, for instance, is often a result of structural heart changes but is not a direct consequence of a PDA itself. Similarly, a heart murmur may be present due to the PDA but is not a complication that arises specifically from it not being treated. Endocarditis is an infection of the inner lining of the heart that can occur with certain