title: Natural aortic valve complications of ventricular septal defect: a prospective cohort study.
abstract: OBJECTIVE
  To study the incidence and onset of aortic valve prolapse (AVP) and aortic regurgitation (AR) in the ventricular septal defect (VSD).
  
  
  METHODS
  A prospective cohort study
  
  
  METHODS
  The less than one-year-old children with diagnosis of isolated VSD were studied from October 2000 to September 2006 at Queen Sirikit National Institute of Child Health. Clinical follow-up and echocardiographic studies were scheduled every 2-3 months in the first year of age and then every 6 months to evaluate the size, location, flow across VSD, aortic valve morphology and aortic regurgitation.
  
  
  RESULTS
  Three hundred and twenty-one cases of VSD were followed up. One was excluded due to associated hypoplastic RV An overall of 2,644 echocardiograms were performed. The percentage of perimembranous, subpulmonic, muscular inlet and multiple types were 70.3%, 19.4%, 5.6%, 3.1% and 1.6%, respectively. Size of the VSD was diagnosed to be small, moderate, and large VSD in 62.5%, 15.9% and 21.6% respectively. At the end of the study, the incidence of AVP in subpulmonic VSD was 87.1% compared to 16.4% in perimembranous VSD, with a relative risk of 5.30 and the incidence of AR in subpulmonic VSD was 37.1% compared to 5.3% in perimembranous VSD, with a relative risk of 6.95. From the survival analysis, the patient with subpulmonic VSD developed AVP at 46%, 77%, 90% and 94% compare to 8%, 13%, 20% and 23% of perimembranous VSD at 12, 24, 36 and 48 months of age respectively (p < 0.001). The patient with subpulmonic VSD developed AR at 8%, 17%, 35% and 38% compare to 2%, 4%, 5% and 7% of perimembranous VSD at 12, 24, 36 and 48 months of age respectively (p < 0.001). At the end of the study, ninety-six cases (30%) underwent cardiac operation with the indication of heart failure or the occurrence of AR. Sixty one cases (19.1%), including two cases of subpulmonic type had spontaneous closure of VSD. Seven cases (2.2%) had lost to follow up and five cases (1.6%) died during the follow up period.
  
  
  CONCLUSIONS
  The incidence of AVP and AR are high in subpulmonic VSD being much higher than perimembranous VSD with a relative risk of 5.30 and 6.95 respectively. These complications are significantly from infancy period and are an indication for early cardiac surgery.
authors.affiliation: Cardiology Unit, Queen Sirikit National Institute of Child Health, Department of Medical Services, College of Medicine, Rangsit University, Bangkok, Thailand. t_layangool@yahoo.com
authors.forename: Thanarat
authors.initials: T
authors.lastname: Layangool
authors.forename: Tawatchai
authors.initials: T
authors.lastname: Kirawittaya
authors.forename: Chaisit
authors.initials: C
authors.lastname: Sangtawesin
authors.forename: Vichow
authors.initials: V
authors.lastname: Kojaranjit
authors.forename: Perapat
authors.initials: P
authors.lastname: Makarapong
authors.forename: Amornrat
authors.initials: A
authors.lastname: Pechdamrongsakul
authors.forename: Yanisa
authors.initials: Y
authors.lastname: Intasorn
authors.forename: Putra
authors.initials: P
authors.lastname: Noisang
mesh_terms: D001021:Aortic Valve / Q000473:pathology*; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D001023:Aortic Valve Prolapse / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality; D005260:Female; D006345:Heart Septal Defects, Ventricular / Q000150:complications* / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012306:Risk; D016019:Survival Analysis; D013997:Time Factors; D014463:Ultrasonography