title: Pulsatile venous waveform quality in Fontan circulation-clinical implications, venous assists options and the future.
abstract: OBJECTIVE
  Functionally univentricular heart (FUH) anomalies are the leading cause of death from all structural birth defects. Total cavopulmonary connection (TCPC) is the last stage of the palliative surgical reconstruction with significant late hemodynamic complications requiring high-risk heart transplantation. Alternative therapeutic options for these critically ill patients are crucial. In Phase I, we investigated the effect of pulsatility of venous flow (VF) waveform on the performance of functional and "failing" Fontan (FF) patients based on conduit power loss. In phase 2, the effect of enhanced external counter pulsation on Fontan circulation flow rates is monitored.
  
  
  METHODS
  In phase 1, Doppler VFs were acquired from FF patients with ventricle dysfunction. Using computational fluid dynamics (CFD), hemodynamic efficiencies of the FF, functional and in-vitro generated mechanically assisted VF waveforms were evaluated. In phase 2, Fontan circulation on sheep model was created and enhanced external counter pulsation (EECP) applied.
  
  
  RESULTS
  Variations in the pulsatile content of the VF waveforms altered conduit efficiency notably. High frequency and low amplitude oscillations lowered the pulsatile component of power losses in FF VF waveforms. The systemic venous flow, pulmonary artery and aorta flows increased by utilizing EECP.
  
  
  CONCLUSIONS
  Our data highlighted the significance of VF pulsatility on energy efficiency inside SV circulation and the feasibility of VF waveform optimization. EECP assist in Fontan circulation can result in venous flow augmentation.
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Children's Hospital of Pittsburgh, PA, USA.
authors.forename: Ergin
authors.initials: E
authors.lastname: Koçyıldırım
authors.forename: Onur
authors.initials: O
authors.lastname: Dur
authors.forename: Ozlem
authors.initials: O
authors.lastname: Soran
authors.forename: Egemen
authors.initials: E
authors.lastname: Tüzün
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Miller
authors.forename: Greggory J
authors.initials: GJ
authors.lastname: Housler
authors.forename: Peter D
authors.initials: PD
authors.lastname: Wearden
authors.forename: Theresa W
authors.initials: TW
authors.lastname: Fossum
authors.forename: Victor O
authors.initials: VO
authors.lastname: Morell
authors.forename: Kerem
authors.initials: K
authors.lastname: Pekkan
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006352:Heart Ventricles / Q000002:abnormalities* / Q000503:physiopathology; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D008297:Male; D011673:Pulsatile Flow / Q000502:physiology; D012756:Sheep; D017725:Ventricular Pressure / Q000502:physiology*