Please tell me, could congenital heart defects (one or more) be diagnosed later on in life?

Variable : Some congenital heart defects almost always present in the first few hours of life. Others, have a variable presentation and may present at any age. The most common standard congenital heart disease to present in adulthood is atrial septal defect. Bicuspid aortic valve also often presents in adulthood, and although it is a congenital anomaly, is not always included in the classification.