It’s unknown why some PDAs remain open well after birth, but these congenital heart defects are more common in babies born prematurely and tend to affect premature infants more severely. Left untreated, a PDA may allow too much blood to enter the lung arteries. This forces the heart and lungs to work harder, and it can cause the lungs to become dangerously congested. Symptoms in newborns, which may not occur until several weeks after birth, include:
- Heart murmur
- Persistent rapid breathing or breathlessness
- Poor eating and slow growth
- Rapid heart rate
- Sweating while crying or eating
Older children and adults can also be diagnosed with a PDA, as they may not cause issues for decades.