title: Disturbed Intracardiac Flow Organization After Atrioventricular Septal Defect Correction as Assessed With 4D Flow Magnetic Resonance Imaging and Quantitative Particle Tracing.
abstract: OBJECTIVE
  Four-dimensional (3 spatial directions and time) velocity-encoded flow magnetic resonance imaging with quantitative particle tracing analysis allows assessment of left ventricular (LV) blood flow organization. Corrected atrioventricular septal defect (AVSD) patients have an abnormal left atrioventricular valve shape. We aimed to analyze flow organization in corrected AVSD patients and healthy controls.
  
  
  METHODS
  A total of 32 patients (age, 25 ± 14 years), 21 after partial AVSD correction and 11 after complete/intermediate AVSD correction, and 30 healthy volunteers (26 ± 12 years) underwent whole-heart four-dimensional velocity-encoded flow magnetic resonance imaging. Particle tracing in the 16-segment LV cavity model was used to quantitatively evaluate blood flow organization discriminating multiple components.
  
  
  RESULTS
  Patients showed a smaller percentage of direct flow compared with controls (30% ± 9% vs 44% ± 11%; P < 0.001). In patients, more inflow was observed in the basal inferior segment (22% ± 11% vs controls, 17% ± 5%; P = 0.005), with less direct but more retained inflow (ie, part of inflow that is not ejected from LV in subsequent systole). In patients, more inflow reached the midventricular level (68% ± 13% vs controls, 58% ± 9%; P < 0.001), most notably as retained inflow in the lateral segments. Subsequently, in patients, more (mostly retained) inflow reached the apex (23% ± 13% vs 14% ± 7%; P < 0.001), which correlated with early peak filling velocity (r = 0.637, P < 0.001). Patients with a corrected complete or intermediate AVSD presented with less direct flow (24% ± 8% vs 33% ± 8%; P = 0.003) and more apical inflow (30% ± 14% vs 18% ± 12%; P = 0.014) compared with a corrected partial AVSD.
  
  
  CONCLUSIONS
  Multicomponent particle tracing combined with 16-segment analysis quantitatively demonstrated altered LV flow organization after AVSD correction, with less direct and more retained inflow in apical and lateral LV cavity segments, which may contribute to decreased cardiac pumping efficiency.
authors.affiliation: From the *Division of Paediatric Cardiology, Department of Paediatrics, †Department of Radiology, ‡Department of Medical Statistics, Leiden University Medical Center, the Netherlands.
authors.forename: Emmeline E
authors.initials: EE
authors.lastname: Calkoen
authors.forename: Patrick J H
authors.initials: PJ
authors.lastname: de Koning
authors.forename: Nico A
authors.initials: NA
authors.lastname: Blom
authors.forename: Lucia J M
authors.initials: LJ
authors.lastname: Kroft
authors.forename: Albert
authors.initials: A
authors.lastname: de Roos
authors.forename: Ron
authors.initials: R
authors.lastname: Wolterbeek
authors.forename: Arno A W
authors.initials: AA
authors.lastname: Roest
authors.forename: Jos J M
authors.initials: JJ
authors.lastname: Westenberg
mesh_terms: D000328:Adult; D003326:Coronary Circulation; D006343:Heart Septal Defects / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011184:Postoperative Period; D011446:Prospective Studies; D012039:Regional Blood Flow