Medical Definition of Septal defect, atrial (ASD)
Septal defect, atrial (ASD): A hole in the septum, the wall, between the atria, the upper chambers of the heart. Commonly called an ASD. ASDs are a major class of heart deformity that is present at birth (congenital cardiac malformation).
Last Editorial Review: 7/1/2016
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?