title: Alteration of LV end-diastolic volume by controlling the power of the continuous-flow LVAD, so it is synchronized with cardiac beat: development of a native heart load control system (NHLCS).
abstract: There are many reports comparing pulsatile and continuous-flow left ventricular assist devices (LVAD). But continuous-flow LVAD with the pulsatile driving technique had not been tried or discussed before our group's report. We have previously developed and introduced a power-control unit for a centrifugal LVAD (EVAHEART®; Sun Medical), which can change the speed of rotation so it is synchronized with the heart beat. By use of this unit we analyzed the end-diastolic volume (EDV) to determine whether it is possible to change the native heart load. We studied 5 goats with normal hearts and 5 goats with acute LV dysfunction because of micro-embolization of the coronary artery. We used 4 modes, "circuit-clamp", "continuous", "counter-pulse", and "co-pulse", with the bypass rate (BR) 100%. We raised the speed of rotation of the LVAD in the diastolic phase with the counter-pulse mode, and raised it in the systolic phase with the co-pulse mode. As a result, the EDV decreased in the counter-pulse mode and increased in the co-pulse mode, compared with the continuous mode (p < 0.05), in both the normal and acute-heart-failure models. This result means it may be possible to achieve favorable EDV and native heart load by controlling the rotation of continuous-flow LVAD, so it is synchronized with the cardiac beat. This novel driving system may be of great benefit to patients with end-stage heart failure, especially those with ischemic etiology.
authors.affiliation: Department of Artificial Organ, National Cerebral and Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, 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: D000818:Animals; D006041:Goats; D006339:Heart Rate / Q000502:physiology*; D006353:Heart-Assist Devices; D008955:Models, Cardiovascular; D011674:Pulse; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
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