ASD: Definition, Uses, and Clinical Overview
ASD most commonly means **atrial septal defect**, a hole or gap in the wall between the heart’s two upper chambers. It is a **congenital heart defect**, meaning it is present from birth. ASD is commonly discussed in cardiology clinics, echocardiography reports, and adult congenital heart disease care. Depending on size and anatomy, an ASD can have little effect or can change how blood flows through the heart and lungs.