ASD is an opening in the intra atrial septum, which creates an anatomical connection between the two upper chambers of the heart. This type of defect can occur in isolation or with other complex congenital heart disease and can often go undiagnosed until childhood or adulthood. The arterial septum has two junctions, the septum primum and the septum secundum. The fusion of these two form the atrial septum, any failure in the fusion of these two structures results an ASD. During fetal life an opening called foramen ovale is maintain from left to right atrium for oxygenated blood to bypass the pulmonary system. After birth the pressure on the left side of the heart increases and the pressure on the right-side decreases. Forcing the foramen ovale to close, if it fails to close this is called patent foramen ovale. Like the patent foramen ovale an ASD is an opening that that remains open even after birth because of a heart deformity.so pre-birth blood flows from right to left in the ASD, after birth the pressure in the left increases causing blood flow to flow from left to right across the defect. Overtime this can cause blood flow increase in right heart and increase flow to pulmonary system causing pulmonary edema and right heart failure. Clinical manifestations include fatigue, exercise intolerance, failure to thrive, poor weight gain, tachypnea, CHF. EKG and CXR usually are normal in patient with an ASD overtime right heart enlargement. An echocardiogram is the diagnostic tool preferred when ASD is suspected. ASD smaller than 6mm usually close by themselves by age 2. Larger ones require closure prior to starting school. A close can be done by cardiac catherization with and occlusive device known as an Amplatzer Septal Occluder or in the OR by suture repair. (Perretta, J. S. 2014).Resources:Perretta, J. S. (2014). Neonatal and pediatric respiratory care a patient case method. F.A. Davis Company.POST 2WILL BE UPLOADED LATER