title: In vitro performance investigation of SynCardia™ Freedom® driver via patient simulator mock loop.
abstract: OBJECTIVE
  The gold standard therapy for patients with advanced heart failure is heart transplant. The gap between donors and patients in waiting lists promoted the development of circulatory support devices, such as the total artificial heart (TAH). Focusing on in vitro tests performed with CardioWest™ TAH (CW) driven by the SynCardia Freedom® portable driver (FD) the present study goals are: i) prove the reliability of a hydraulic circuit used as patient simulator to replicate a quasi-physiological scenario for various hydrodynamic conditions, ii) investigate the hydrodynamic performance of the CW FD, iii) help clinicians in possible interpretation of clinical cases outcomes.
  
  
  METHODS
  In vitro tests were performed using a mechanic-hydraulic patient simulator. Cardiac output (CO), CW ventricles filling, atrial, ventricles, aortic and pulmonary artery pressures were measured for different values of vascular resistance in both systemic (SVR) and pulmonary (PVR) physiological range.
  
  
  RESULTS
  After increasing the PVR, the left atrial pressure decreased according to the expected physiological trend, while aortic pressure remained almost stable, proving the ability of the simulator to mimic a physiological scenario. Unexpectedly, the mean pulmonary artery pressure (PPA) was found to increase above 30 mmHg in the range of physiological PVR (2.6 WU) and for constant CO.
  
  
  CONCLUSIONS
  The increase in PPA is probably associated with the pre-set driving setup of the FD. The finding suggests a possible explanation of the clinical course of a patient who experienced complications soon after being supported by the FD, with the occurrence of dyspnea and pulmonary edema despite a high cardiac index.
authors: Cardiovascular Fluid Dynamics Laboratory HER, Department of Civil, Environmental and Architectural Engineering - DICEA, University of Padua, Padua - Italy.
authors: Riccardo
authors: R
authors: Toninato
authors: Padua Heart Project, Division of Cardiac Surgery, A.O. of Padua, Padua - Italy.
authors: Silvia
authors: S
authors: Scuri
authors: Division of Cardiac Surgery, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua - Italy.
authors: Vincenzo
authors: V
authors: Tarzia
authors: Division of Cardiac Surgery, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua - Italy.
authors: Gino
authors: G
authors: Gerosa
authors: Cardiovascular Fluid Dynamics Laboratory HER, Department of Civil, Environmental and Architectural Engineering - DICEA, University of Padua, Padua - Italy.
authors: Francesca M
authors: FM
authors: Susin
mesh_terms: D001794:Blood Pressure; D002302:Cardiac Output; D006333:Heart Failure / Q000628:therapy*; D006354:Heart, Artificial; D006801:Humans; D008954:Models, Biological; D011651:Pulmonary Artery; D014655:Vascular Resistance