title: Fontan hemodynamics from 100 patient-specific cardiac magnetic resonance studies: a computational fluid dynamics analysis.
abstract: OBJECTIVE
  This study sought to quantify average hemodynamic metrics of the Fontan connection as reference for future investigations, compare connection types (intra-atrial vs extracardiac), and identify functional correlates using computational fluid dynamics in a large patient-specific cohort. Fontan hemodynamics, particularly power losses, are hypothesized to vary considerably among patients with a single ventricle and adversely affect systemic hemodynamics and ventricular function if suboptimal.
  
  
  METHODS
  Fontan connection models were created from cardiac magnetic resonance scans for 100 patients. Phase velocity cardiac magnetic resonance in the aorta, vena cavae, and pulmonary arteries was used to prescribe patient-specific time-averaged flow boundary conditions for computational fluid dynamics with a customized, validated solver. Comparison with 4-dimensional cardiac magnetic resonance velocity data from selected patients was used to provide additional verification of simulations. Indexed Fontan power loss, connection resistance, and hepatic flow distribution were quantified and correlated with systemic patient characteristics.
  
  
  RESULTS
  Indexed power loss varied by 2 orders of magnitude, whereas, on average, Fontan resistance was 15% to 20% of published values of pulmonary vascular resistance in single ventricles. A significant inverse relationship was observed between indexed power loss and both systemic venous flow and cardiac index. Comparison by connection type showed no differences between intra-atrial and extracardiac connections. Instead, the least efficient connections revealed adverse consequences from localized Fontan pathway stenosis.
  
  
  CONCLUSIONS
  Fontan power loss varies from patient to patient, and elevated levels are correlated with lower systemic flow and cardiac index. Fontan connection type does not influence hemodynamic efficiency, but an undersized or stenosed Fontan pathway or pulmonary arteries can be highly dissipative.
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga.
authors: Christopher M
authors: CM
authors: Haggerty
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga.
authors: Maria
authors: M
authors: Restrepo
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga.
authors: Elaine
authors: E
authors: Tang
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga; Interface Group, Institute of Physiology, University of Zürich, Zürich, Switzerland.
authors: Diane A
authors: DA
authors: de Zélicourt
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga.
authors: Kartik S
authors: KS
authors: Sundareswaran
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga.
authors: Lucia
authors: L
authors: Mirabella
authors: Westat, Inc, Rockville, Md.
authors: James
authors: J
authors: Bethel
authors: Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pa.
authors: Kevin K
authors: KK
authors: Whitehead
authors: Division of Cardiology, Children's Hospital of Philadelphia, Philadelphia, Pa.
authors: Mark A
authors: MA
authors: Fogel
authors: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Ga. Electronic address: ajit.yoganathan@bme.gatech.edu.
authors: Ajit P
authors: AP
authors: Yoganathan
mesh_terms: D002648:Child; D005260:Female; D018729:Fontan Procedure / Q000379:methods*; D006330:Heart Defects, Congenital / Q000175:diagnosis* / Q000601:surgery*; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008955:Models, Cardiovascular