title: Natural history of growth of secundum atrial septal defects and implications for transcatheter closure.
abstract: OBJECTIVE
  To investigate the natural history of secundum atrial septal defects (ASDs) over several years using serial echocardiographic studies.
  
  
  METHODS
  All patients with isolated secundum ASDs who had serial transthoracic echocardiograms at Texas Children's Hospital, Houston, Texas, from January 1991 to December 1998 were identified. Patients with fenestrated or multiple ASDs, other congenital heart defects, or less than a six month interval between echocardiograms were excluded. There were 104 patients eligible for inclusion in the study. Studies were reviewed by two echocardiographers (blinded) and the maximal diameter was recorded. Defects were defined as small (> 3 mm to < 6 mm), moderate (> or = 6 mm to < 12 mm), or large (> or = 12 mm). ASDs that grew > or = 20 mm were defined as having outgrown transcatheter closure with the device available to the authors' institution.
  
  
  RESULTS
  ASD diameter increased in 68 of 104 patients (65%), including 31 patients (30%) with a > 50% increase in diameter. Spontaneous closure occurred in four patients (4%). Thirteen defects (12%) increased to > or = 20 mm. One fifth of the patients studied had an insufficient atrial rim by transthoracic echocardiogram to hold an atrial septal occluder. The only factor associated with significant growth of ASDs was initial size of the defect. ASD growth was independent both of age at diagnosis and when indexed to body surface area.
  
  
  CONCLUSIONS
  Two thirds of secundum ASDs may enlarge with time and there is the potential for secundum ASDs to outgrow transcatheter closure with specific devices. Further development in devices and general availability of devices capable of closing larger ASDs should circumvent this problem.
authors.affiliation: The LillieFrank Abercrombie Division of Pediatric Cardiology, Texas Children's Hospital and Baylor College of Medicine, Houston, 6621 Fannin, Texas 77030, USA. cmcmahon@bcm.tmc.edu
authors.forename: C J
authors.initials: CJ
authors.lastname: McMahon
authors.forename: T F
authors.initials: TF
authors.lastname: Feltes
authors.forename: J K
authors.initials: JK
authors.lastname: Fraley
authors.forename: J T
authors.initials: JT
authors.lastname: Bricker
authors.forename: R G
authors.initials: RG
authors.lastname: Grifka
authors.forename: T A
authors.initials: TA
authors.lastname: Tortoriello
authors.forename: R
authors.initials: R
authors.lastname: Blake
authors.forename: L I
authors.initials: LI
authors.lastname: Bezold
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014463:Ultrasonography