3 types: ostium primum (common in Down syndrome), ostium secundum (most common type, 50-70%), sinus venosus (defect located at entry of superior vena cava into right atrium)
epidemiology: 6-8% of congenital heart lesions
natural history:
80-100% spontaneous closure rate if ASD diameter <8 mm
if remains patent, congestive heart failure (CHF) and pulmonary hypertension can develop in adult life
clinical presentation:
history: often aSx in childhood
Px: grade 2-3/6 pulmonic outflow murmur, widely split and fixed S2
investigations:
ECG: right axis deviation (RAD), mild RVH, right bundle branch block (RBBB)
CXR: increased pulmonary vasculature
management: elective surgical or catheter closure between 2-5 yr of age