Peripheral vascular reactivity in patients with pulsatile vs axial flow left ventricular assist device support

J Heart Lung Transplant. 2006 Apr;25(4):391-4. doi: 10.1016/j.healun.2005.11.439. Epub 2006 Feb 3.


Background: Left ventricular assist devices (LVADs) are either pulsatile or axial flow devices. The latter can be operated at a low-speed setting to allow pulsatility or at a high-speed setting to create continuous flow. The purpose of this study was to compare the effect of continuous flow and pulsatile flow on peripheral vascular reactivity.

Methods: Twenty consecutive patients were divided into two groups based on the type of LVAD they received. Ten patients had a pulsatile flow LVAD, and 10 had an axial flow LVAD. For the purpose of the study protocol, the axial flow devices were operated at a high speed to ensure continuous flow. The patients' peripheral artery vasoreactivity was assessed with an ultrasound vascular transducer that measured flow-mediated dilation (FMD).

Results: The FMD of the patients supported with pulsatile flow (15.6 +/- 5%) was higher than the FMD of the patients supported with temporary continuous flow (1.8 +/- 3%). The difference was statistically significant (p < 0.0001).

Conclusions: Pulsatile flow is associated with a better peripheral vascular reactivity than continuous flow. Patients supported by axial flow devices should be kept on the lowest speed setting to allow maximum pulsatility.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Brachial Artery / physiology*
  • Equipment Design
  • Female
  • Heart Failure / surgery*
  • Heart-Assist Devices*
  • Humans
  • Male
  • Middle Aged
  • Pulsatile Flow / physiology*
  • Vasodilation / physiology*