title: Change of coronary flow by continuous-flow left ventricular assist device with cardiac beat synchronizing system (native heart load control system) in acute ischemic heart failure model.
abstract: BACKGROUND
  A novel control system for the EVAHEART left ventricular assist device (LVAD), known as the Native Heart Load Control System (NHLCS), can change the device's rotational speed (RS) in synchrony with the heartbeat. The system enhanced coronary flow (CoF) with the counter-pulse mode in normal goats' hearts, so we examined the change in CoF in goats with acute ischemic heart failure (HF).
  
  
  RESULTS
  We studied 14 goats (56.1±6.9kg) with acute ischemic HF induced by coronary microsphere embolization. We installed EVAHEART and ran the device in 4 modes [continuous support, circuit-clamp, counter-pulse (raise RS in diastole), and co-pulse (raise RS in systole)] with 50% or 100% bypass in each mode. In comparison with the circuit-clamp mode, CoF was 121.0±14.1% in the counter-pulse mode and 102.9±7.9% in the co-pulse mode, whereas it was 113.5±10.6% in the continuous mode, with 100% bypass (P<0.05). The same difference was confirmed with 50% bypass. The results indicated that a LVAD in an acute ischemic heart enhanced CoF, and that CoF was greater in the counter-pulse mode and smaller in the co-pulse mode relative to the continuous mode.
  
  
  CONCLUSIONS
  By using NHLCS to change CoF, recovery of native heart function with a LVAD has a better prognosis.
authors.affiliation: Department of Cardiothoracic Surgery, The University of Tokyo, Tokyo, Japan. louvre1974@yahoo.co.jp
authors.forename: Akihide
authors.initials: A
authors.lastname: Umeki
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishimura
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ando
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Takewa
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Shunei
authors.initials: S
authors.lastname: Kyo
authors.forename: Minoru
authors.initials: M
authors.lastname: Ono
authors.forename: Tomonori
authors.initials: T
authors.lastname: Tsukiya
authors.forename: Toshihide
authors.initials: T
authors.lastname: Mizuno
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Taenaka
authors.forename: Eisuke
authors.initials: E
authors.lastname: Tatsumi
mesh_terms: D000208:Acute Disease; D000818:Animals; D006041:Goats; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006352:Heart Ventricles / Q000503:physiopathology*; D006353:Heart-Assist Devices; D017202:Myocardial Ischemia / Q000503:physiopathology* / Q000628:therapy*