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Patient Education: Diseases Conditions Treatments & Procedures

Atrial Septal Defect (ASD)


ASD occurs before birth. It is an abnormal opening in the wall between the two upper chambers (atria) of the heart, which allows blood flow between these chambers causing the opening to allow extra blood to go to the lungs, which may increase the heart's workload. Some individuals with an ASD may experience no symptoms, but others could experience:

  • respiratory infections (colds)
  • fatigue (tiredness)
  • shortness of breath on exertion
  • irregular heart beat