title: Concomitant pulsatile and continuous flow VAD in biventricular and univentricular physiology: a comparison study with a numerical model.
abstract: BACKGROUND
  To develop and test a lumped parameter model to simulate and compare the effects of the simultaneous use of continuous flow (CF) and pulsatile flow (PF) ventricular assist devices (VADs) to assist biventricular circulation vs. single ventricle circulation in pediatrics.
  
  
  METHODS
  Baseline data of 5 patients with biventricular circulation eligible for LVAD and of 5 patients with Fontan physiology were retrospectively collected and used to simulate patient baselines. Then, for each patient the following simulations were performed: (a) CF VAD to assist the left ventricle (single ventricle) + a PF VAD to assist the right ventricle (cavo-pulmonary connection) (LCF + RPF); (b) PF VAD to assist the left ventricle (single ventricle) + a CF VAD to assist the right ventricle (cavo-pulmonary connection) (RCF + LPF).
  
  
  RESULTS
  In biventricular circulation, the following results were found: cardiac output (17% RCF + LPF, 21% LCF + RPF), artero-ventricular coupling (-36% for the left ventricle and -21.6% for the right ventricle), pulsatility index (+6.4% RCF + LPF, p = 0.02; -8.5% LCF + RPF, p = 0.00009). Right (left) atrial pressure and right (left) ventricular volumes are decreased by the RCF + LPF (by RPF + LCF). Pulmonary arterial pressure decreases in the LCF + RPF configuration. In Fontan physiology: cardiac output (LCF + RPF 35% vs. 8% in RCF + LPF), ventricular preload (+4% RCF + LPF, -10% LCF + RPF), Fontan conduit pressure (-5% RCF + LPF, +7% LCF + RPF), artero-ventricular coupling (-14% RCF + LPF vs. -41% LCF + RPF) and pulsatility (+13% RCF + LPF, - 8% LCF + RPF).
  
  
  CONCLUSIONS
  A numerical model supports clinicians in defining and innovating the VAD implantation strategy to maximize the hemodynamic benefits. Results suggest that the hemodynamic benefits are maximized by the LCF + RPF configuration.
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome - Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Di Molfetta
authors.affiliation: Institute of Clinical Physiology, National Research Center, Rome - Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Ferrari
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome - Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Iacobelli
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome - Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Filippelli
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome - Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Guccione
authors.affiliation: Department of Cardiac Surgery, Catholic University of Leuven, Leuven - Belgium.
authors.forename: Libera
authors.initials: L
authors.lastname: Fresiello
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome - Italy.
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Perri
authors.affiliation: Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome - Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Amodeo
mesh_terms: D002302:Cardiac Output / Q000502:physiology; D002675:Child, Preschool; D003198:Computer Simulation; D005260:Female; D018729:Fontan Procedure; D006333:Heart Failure / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D008955:Models, Cardiovascular; D011673:Pulsatile Flow; D012189:Retrospective Studies