Ostium secundum atrial septal defect in the elderly. Atrial septal defect (ASD) is one of the most common congenital cardiac anomalies in adults. Life expectancy is shortened, and almost 90% of patients die by the age of 60 years. The progression of this congenital disease to congestive heart failure has been related to several factors such as the onset of pulmonary hypertension, arrhythmias, bronchopulmonary infections, or the development of other cardiovascular disease. We describe three cases of very old patients with significant ASDs and late development of symptoms. Given the higher risks and poorer long-term results of surgical closure of the defect in advanced age, the indications for such an intervention in elderly patients should be carefully evaluated. 