Secundum atrial septal defect: routine surgical treatment is not of proven benefit.

Secundum atrial septal defect accounts for 10% of congenital heart disease4 at birth and for 30-40% of cases seen in adults.5 Approximately 300-400 patients undergo surgical closure of atrial septal defect in the United Kingdom each year. Reports of the natural history of atrial septal defect and of the indications for and results of surgery imply that patients become increasingly symptomatic with advancing years, that surgical closure in childhood prevents this happening and in adult life reverses the deterioration. It is therefore widely but not universally6 advocated that atrial septal defects with a pulmonary to systemic flow ratio > 1 5:1 should be closed.5 The evidence to justify this policy is weak.