Many babies born with atrial septal defects have no signs or symptoms. Signs or symptoms can begin in adulthood. Atrial septal defect signs and symptoms can include: 
Shortness of breath, especially when exercising
Fatigue
Swelling of legs, feet or belly (abdomen)
Irregular heartbeats (arrhythmias)
Sensation of a rapid, pounding heartbeat (palpitations) or skipped beats
Whooshing sound that can be heard through a stethoscope (heart murmur)
