All of the following are true about ASD ilk except –

In ASD there is abnormal communication between left and right atria which causes left to right shunt because pressure in left atrium is higher (3-5 mm Hg) than right atrial piessure. This results in : - Volume overload to right atrium  → Dilatation and hypertrophy of right atrium. Volume overlead to right ventricle  → Dilatation and hypertrophy of right ventricle. Increased blood flow through lungs → Pulmonary plethora which can cause pulmonary hypertension.