Peripheral vascular reactivity in patients with pulsatile vs axial flow left ventricular assist device support.
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.
Amir
Offer
O
Department of Adult Cardiology/Heart Failure, Texas Heart Institute, St. Luke's Episcopal Hospital, Houston, Texas 77030, USA.
Radovancevic
Branislav
B
Delgado
Reynolds M
RM
Kar
Biswajit
B
Radovancevic
Rajko
R
Henderson
Maria
M
Cohn
William E
WE
Smart
Frank W
FW
D000328:Adult; D000368:Aged; D001916:Brachial Artery / Q000502:physiology*; D004867:Equipment Design; D005260:Female; D006333:Heart Failure / Q000601:surgery*; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow / Q000502:physiology*; D014664:Vasodilation / Q000502:physiology*