What can PDA lead to?

What Happens If PDA Is Left Untreated?

Patent Ductus Arteriosus (PDA) is a condition most commonly seen in newborns, especially premature infants, where a blood vessel called the ductus arteriosus fails to close after birth. While small PDAs may close on their own or cause minimal issues, untreated larger PDAs can lead to serious complications over time.

When the ductus remains open, oxygen-rich blood from the aorta mixes back into the pulmonary artery, increasing blood flow to the lungs. This extra strain on the heart and lungs can lead to long-term damage if not addressed. One of the most concerning outcomes is pulmonary hypertension—high blood pressure in the lung arteries—which forces the heart to work harder than normal.

Over years, this increased pressure can cause irreversible changes in the lung vessels, potentially resulting in Eisenmenger syndrome. This serious condition occurs when the direction of blood flow reverses, sending oxygen-poor blood directly into the body, causing symptoms like cyanosis (a bluish tint to the skin) and extreme fatigue.

Additionally, chronic PDA can weaken the heart muscle over time, eventually leading to heart failure—a condition where the heart can't pump efficiently. Another rare but dangerous risk is endarteritis, an infection of the inner lining of the heart or blood vessels, which can arise when abnormal blood flow creates areas where bacteria can take hold.

Early diagnosis and treatment—whether through medication, catheter-based procedures, or surgery—can prevent these complications entirely. For infants and adults diagnosed with PDA, timely intervention is key to ensuring a normal, healthy life. Ignoring the condition, however, can lead to severe, even life-threatening outcomes.