Real Time Three-dimensional Echocardiography Provides New Insight into the Mechanisms of Left Atrioventricular Valve Regurgitation in Patients with Atrioventricular Septal defect

  • Dr Ken Takahashi, Dept of Pediatrics, University of Alberta and Stollery Children`s Hospital, Edmonton, AB, Canada, Canada
  • Dr Ghassan Al-Naami, Dept of Pediatrics, University of Alberta and Stollery Children`s Hospital, Edmonton, AB, Canada, Canada
  • Dr Akio Inage, University of Alberta and Stollery Children`s Hospital, Canada
  • Dr Andrew Mackie, Dept of Pediatrics, University of Alberta and Stollery Children`s Hospital, Edmonton, AB, Canada, Canada
  • Dr Ivan Rebeyka, University of Alberta and Stollery Children`s Hospital, Canada
  • Dr David Ross, Dept of Surgery, University of Alberta and Stollery Children`s Hospital, Edmonton, AB, Canada
  • Dr Richard Thompson, Dept of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada
  • Dr Jeffrey Smallhorn, Dept of Pediatrics, University of Alberta and Stollery Children`s Hospital, Edmonton, AB, Canada

    • Background: Although left atrioventricular valve (LAVV) regurgitation in patients with atrioventricular septal defect (AVSD) has an important negative impact on outcome, the mechanisms are still unclear.
    Methods: Real time 3-dimensional (3D) echocardiography was performed in 59 patients with AVSD (aged 3.3 – 32 .6 years) (28 partitioned and 31 common AVV orifice) and 40 normal controls (aged 3.4 - 31.5 years). 30 points around the LAVV annulus, the tip of the papillary muscles (PM) and the surfaces of the LAVV leaflets were converted into 3D (x,y,z) coordinates. Deformities of the LAVV were evaluated by 3D re-constructed images.
    Results: There were 28 patients with mild (Group 1) and 31 with moderate (Group 2) LAVV regurgitation. 15/31 (48.4%) patients in Group 2 had a deformity of the inferior bridging leaflet (IBL) and a commissural abnormality between IBL and mural leaflet (ML) compared to 2/28 (7.1%) and 5/28 (17.9%) patients in Group 1 (p < 0.001), respectively. Annular area and the prolapsed volume were greater in Group 2 than Group 1 and controls (p < 0.001). In group 2, the anterolateral PM was more laterally displaced than in group 1 and controls (p < 0.001 and < 0.05 respectively). Older age, larger annular area and lateral displacement of the anterior PM were significantly correlated with moderate LAVV regurgitation by multivariable analysis.
    Conclusion: In AVSD, significant LAVV regurgitation is associated with aging, larger annular area, lateral papillary muscle displacement, prolapse and structural abnormalities of the IBL. These findings may impact on future surgical management.