The current generation of left ventricular assist devices (LVADs) provides continuous flow and has the capacity to reduce aortic pulsatility, which may be related to a range of complications associated with these devices. Pulsed LVAD operation using speed modulation presents a mechanism to restore aortic pulsatility and potentially mitigate complications. We sought to investigate the interaction of axial and centrifugal LVADs with the LV and quantify the effects of continuous and pulsed LVAD operations on LV generated wave patterns under different physiologic conditions using wave intensity analysis (WIA) method. The axial LVAD created greater wave intensity associated with LV relaxation. In both LVADs, there were only minor and variable differences between the continuous and pulsed operations. The response to physiologic stress was preserved with LVAD implantation as wave intensity increased marginally with volume loading and significantly with infusion of norepinephrine. Our findings and a new approach of investigating aortic wave patterns based on WIA are expected to provide useful clinical insights to determine the ideal operation of LVADs.
From the *Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
†Formerly: Bonde Artificial Heart Laboratory, Department of Surgery, Yale School of Medicine, New Haven, Connecticut
‡Bonde Artificial Heart Laboratory, Department of Surgery, Yale School of Medicine, New Haven, Connecticut
§Cardiac Surgery, Department of Surgery, Yale School of Medicine, New Haven, Connecticut
¶Department of Electrical and Computer Engineering, California State University, Northridge, California.
Submitted for consideration September 2017; accepted for publication in revised form March 2018.
Disclosure: The authors have no conflicts of interest to report.
The project described was supported by National Institutes of Health/National Heart, Lung, and Blood Institute (NHLBI) grant No. R21HL118611. No relationships with industry to report.
Part of this work was presented at American Heart Association Scientific Sessions in Anaheim, CA, Nov 2017.
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Correspondence: Pramod Bonde, Center for Advanced Heart Failure and Transplantation, Yale School of Medicine, Yale New Haven Hospital, 330 Cedar Street, 204 Boardman, P.O. Box 208039, New Haven, CT 06520. Email: firstname.lastname@example.org.