All of the following are true about ASD ilk except –
Right atrial hypertrophy
Left atrial hypertrophy
Right ventricular hypertrophy
Pulmonary hypertension
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.