title: Synchrony relationships between the left ventricle and a left ventricular assist device: an experimental study in pigs.
abstract: BACKGROUND
  Synchronization between the left ventricle and a left ventricular assist device (LVAD) may be important for ventricular unloading and coronary perfusion. We assessed the synchrony between cardiac and LVAD cycles by increasing delays in steps of 100 msec throughout the cycle, under conditions of total and partial left ventricular support.
  
  
  METHODS
  We studied 7 healthy minipigs weighing 30-40 kg. A 60-cc Berlin Heart Excor LVAD was implanted and connected to a BCM 1200 console, making it possible to synchronize the LVAD systole and the EKG signal with a prefixed delay. We recorded hemodynamic parameters (including aortic, pulmonary, and left ventricular pressure) and LVAD flow for each delay.
  
  
  RESULTS
  Intraventricular pressure during LVAD systole was minimized with delays of around 40-80% of one cycle. In addition, total flow was higher under these conditions.
  
  
  CONCLUSIONS
  This study shows that the synchronous mode of LVAD operation is feasible. Moreover, a delay in device contraction until the second half of the cardiac cycle optimizes ventricular unloading and may eventually improve myocardial recovery.
authors.affiliation: Department of Cardiac Surgery, Gregorio Marañon General University Hospital, Madrid - Spain.
authors.forename: Angeles
authors.initials: A
authors.lastname: Heredero
authors.forename: Ramon
authors.initials: R
authors.lastname: Perez-Caballero
authors.forename: Javier
authors.initials: J
authors.lastname: Otero
authors.forename: Daniel
authors.initials: D
authors.lastname: Rodríguez-Martínez
authors.forename: Begoña
authors.initials: B
authors.lastname: Quintana-Villamandos
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rodríguez-Bernal
authors.forename: Ángel
authors.initials: Á
authors.lastname: González-Pinto
authors.forename: Manuel
authors.initials: M
authors.lastname: Ruiz-Fernandez
authors.forename: Juan F
authors.initials: JF
authors.lastname: Del Cañizo
mesh_terms: D000818:Animals; D062186:Arterial Pressure / Q000502:physiology; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology*; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D013552:Swine; D016277:Ventricular Function, Left / Q000502:physiology*