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J Artif Organs. 2017 Mar;20(1):18-25. doi: 10.1007/s10047-016-0920-y. Epub 2016 Jul 19.

Changing pulsatility by delaying the rotational speed phasing of a rotary left ventricular assist device.

Author information

1
Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan. miracle5jp@yahoo.co.jp.
2
Department of Cardiothoracic Surgery, The University of Tokyo, Tokyo, Japan. miracle5jp@yahoo.co.jp.
3
Department of Cardiac Surgery, Tokyo Metropolitan Geriatric Hospital, 35-2 Sakaecho, Itabashi, Tokyo, 173-0015, Japan. takashin-tky@umin.ac.jp.
4
Department of Artificial Organs, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka, 565-8565, Japan.
5
Department of Cardiothoracic Surgery, The University of Tokyo, Tokyo, Japan.

Abstract

Continuous-flow left ventricular assist devices (LVADs) have improved the prognosis of end-stage heart failure. However, continuous-flow LVADs diminish pulsatility, which possibly result in bleeding, aortic insufficiency, and other adverse effects. We previously developed a novel control system for a continuous-flow LVAD (EVAHEART®; Sun Medical), and demonstrated that we could create sufficient pulsatility by increasing its rotational speed (RS) in the systolic phase (Pulsatile Mode) in the normal heart model. Here, we aimed to evaluate differences between systolic assist with advanced and delayed loads by shifting the timing of increased RS. We implanted EVAHEART in six goats (55.3 ± 4.3 kg) with normal hearts. We reduced their heart rates to <60 bpm using propranolol and controlled the heart rates at 80 and 120 bpm using ventricular pacing. We shifted the timing of increasing RS from -60 to +60 ms in the systolic phase. We found significant increases in all the following parameters when assessments of delayed timing (+60 ms) were compared with assessments of advanced timing (-60 ms): pulse pressure, mean dP/dt max of aortic pressure, and energy-equivalent pulse pressure. During continuous-flow LVAD support, pulsatility can be controlled using a rotary pump. In particular, pulsatility can be shifted by delaying increased RS.

KEYWORDS:

Continuous-flow LVAD; Rotary pump; Synchronization with cardiac beat

PMID:
27436097
DOI:
10.1007/s10047-016-0920-y
[Indexed for MEDLINE]

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