title: Increased common atrioventricular valve tenting is a risk factor for progression to severe regurgitation in patients with a single ventricle with unbalanced atrioventricular septal defect.
abstract: OBJECTIVE
  Significant atrioventricular valve regurgitation (AVVR) increases mortality in patients with unbalanced atrioventricular septal defects (uAVSDs) and a single ventricle. We tested the hypothesis that abnormal leaflet tethering is associated with progressive AVVR in patients with a single ventricle with uAVSD.
  
  
  METHODS
  We retrospectively reviewed the initial presentation and prebidirectional cavopulmonary anastamosis echocardiograms of 46 consecutive patients with uAVSD with single ventricle palliation. AVVR was graded as moderate to severe if the sum of vena contracta width to dominant valve annulus ratio was ≥ 0.33. We measured tenting height, annular to leaflet angle and annular diameter, indexed to patient size where appropriate. Multivariate analysis of variables to predict progressive AVVR was performed.
  
  
  RESULTS
  At follow-up of 3.3 ± 2.4 years, 24 patients had mild AVVR (Group A) and 22 had moderate to severe AVVR. Overall mortality was 6%, whereas 10 had valve repair/replacement surgery. Of 22 patients with severe AVVR at follow-up, 9 had severe AVVR at initial presentation (Group B), whereas 13 had mild AVVR at presentation but developed severe AVVR at their prebidirectional cavopulmonary anastamosis echocardiogram (Group C). Group A patients had a smaller tenting height at initial presentation compared with patients in Group B and Group C, and also had early progressive reduction of indexed tenting height (P < .01). An absolute tenting height >6 mm (odds ratio, 6.6; 95% confidence interval, 1.1-39.0; P = .03) at the initial echocardiogram was identified as an independent predictor of subsequent severe AVVR.
  
  
  CONCLUSIONS
  Early leaflet tethering is predictive of subsequent AVVR in patients with a single ventricle with uAVSD. Patients with competent AVV had progressive reduction in the degree of leaflet tethering, whereas patients with AVVR did not. This may represent an important adaptive process to maintain valve competency in uAVSD.
authors.affiliation: Faculty of Medicine and Dentistry, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada. Electronic address: cvijarnsorn@yahoo.com.
authors.forename: Chodchanok
authors.initials: C
authors.lastname: Vijarnsorn
authors.affiliation: Faculty of Medicine and Dentistry, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Nee Scze
authors.initials: NS
authors.lastname: Khoo
authors.affiliation: Faculty of Medicine and Dentistry, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Edythe B
authors.initials: EB
authors.lastname: Tham
authors.affiliation: Faculty of Medicine and Dentistry, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Timothy
authors.initials: T
authors.lastname: Colen
authors.affiliation: Faculty of Medicine and Dentistry, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Rebeyka
authors.affiliation: Faculty of Medicine and Dentistry, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Smallhorn
mesh_terms: D000015:Abnormalities, Multiple; D006348:Cardiac Surgical Procedures; D016009:Chi-Square Distribution; D002675:Child, Preschool; D005260:Female; D006343:Heart Septal Defects / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D006349:Heart Valve Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D006351:Heart Valves / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D006352:Heart Ventricles / Q000002:abnormalities* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D010166:Palliative Care; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography