Most common type of Atrial septal defect is:

(Ostium secondum) (400-G) (401-Ghai 7th)Atrial septal defect - ostium secondum type is 10 times more common than the endocardial cushion defrct.* Ostium secondum - generally anatomically located at the fossa ovalis superior or posterior to the fossa - ovalis.* Ostium primum - is situated inferior to the fossa-ovalis* CHF, Infective endocarditis is rare* The ideal age of operation is between 2-5 years.