An ostium primum atrial septal defect (ASD) occurs when then atrial septum near the atrioventricular valves has a communication between the two atrium causing a left to right shunt. This rarely ...

An atrial septal defect of the secundum type is relatively common and occurs from failure of the septum secundum to develop. This results in a communication between the left and right atrium directly ...

This paper presents serial cardiac-catheterization data showing spontaneous functional closure of large symptomatic defects in 3 infants. One had an associated moderate-sized patent ductus arteriosus ...

Atrial septal defect is an abnormal hole in the fibrous membrane separating the two smaller, collecting chambers of the heart (atria). There are no clear reasons for the development of septal defects.

An atrial septal defect is an opening or hole in the wall that sits between the heart’s two upper chambers. The heart’s upper chambers are called the right and left atria. Some people refer to atrial ...