The diagnosis is made through tests such as transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and cardiac CT. If pulmonary hypertension is suspected, a cardiac catheterization may be necessary for further evaluation.
In cases of secundum ASD, size of the defect and the surrounding tissues are evaluated. If the anatomy is suitable, cather-based procedure may be performed to close the hole without surgery. If the defect is too large or the tissue is not sufficient, surgery may be required instead. For types of ASD other than secundum ASD, surgery is usually required. If pulmonary hypertension is present, several factors are considered to decide the most appropriate treatment method.