Prognosis of patients with unrepaired ASDs is thought to be shortened and repair can avoid right ventricular (RV) failure, pulmonary hypertension, thrombo-embolic events and atrial dysrrhythmias. So, when the defect is discovered early, an ASD is usually closed in childhood, unless the defect is considered not to be clinical significant. Sometimes, as most patients with an isolated ASD are asymptomatic during childhood, an ASD comes to medical attention at an older age.