TY - JOUR
T1 - Continuous-Flow Left Ventricular Assist Device Support Improves Myocardial Supply:Demand in Chronic Heart Failure
AU - Soucy, Kevin G.
AU - Bartoli, Carlo R.
AU - Phillips, Dustin
AU - Giridharan, Guruprasad A.
AU - Sobieski, Michael A.
AU - Wead, William B.
AU - Dowling, Robert D.
AU - Wu, Zhongjun J.
AU - Prabhu, Sumanth D.
AU - Slaughter, Mark S.
AU - Koenig, Steven C.
N1 - Funding Information:
The authors thank the following individuals for their support of this study: Karen Lott, Laura Lott, Cary Woolard, and Leslie Sherwood, DVM. This study was completed, in part, in support of the doctoral thesis and dissertation of C.R. Bartoli, MD, PhD entitled Partial vs. Full Support of the Heart with a Continuous -Flow Left Ventricular Assist Device: Implications for Myocardial Recovery . Funding for this project was provided, in part, by Roger M. Prizant Research Trust Fund, University of Louisville Clinical Translational Science Pilot Grant Program, and University of Louisville Cardiac Implant Science Endowment. Dr. Slaughter and Dr. Koenig have received funding unrelated to this study from industry sponsors for training and pre-clinical testing (HeartWare, Miami Lakes FL; St. Jude Medical, Minneapolis MN; Thoratec, Pleasanton CA). The authors have no other conflicts of interest to disclose. The left ventricular assist devices were provided by HeartWare (Miami Lakes, FL) and Thoratec (Pleasanton, CA) under material transfer agreements (MTA).
Publisher Copyright:
© 2017, Biomedical Engineering Society.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Continuous-flow left ventricular assist devices (CF LVADs) are rotary blood pumps that improve mean blood flow, but with potential limitations of non-physiological ventricular volume unloading and diminished vascular pulsatility. In this study, we tested the hypothesis that left ventricular unloading with increasing CF LVAD flow increases myocardial flow normalized to left ventricular work. Healthy (n = 8) and chronic ischemic heart failure (IHF, n = 7) calves were implanted with CF LVADs. Acute hemodynamics and regional myocardial blood flow were measured during baseline (LVAD off, clamped), partial (2–4 L/min) and full (>4 L/min) LVAD support. IHF calves demonstrated greater reduction of cardiac energy demand with increasing LVAD support compared to healthy calves, as calculated by rate-pressure product. Coronary artery flows (p < 0.05) and myocardial blood flow (left ventricle (LV) epicardium and myocardium, p < 0.05) decreased with increasing LVAD support in normal calves. In the IHF model, blood flow to the septum, LV, LV epicardium, and LV myocardium increased significantly with increasing LVAD support when normalized to cardiac energy demand (p < 0.05). In conclusion, myocardial blood flow relative to cardiac demand significantly increased in IHF calves, thereby demonstrating that CF LVAD unloading effectively improves cardiac supply and demand ratio in the setting of ischemic heart failure.
AB - Continuous-flow left ventricular assist devices (CF LVADs) are rotary blood pumps that improve mean blood flow, but with potential limitations of non-physiological ventricular volume unloading and diminished vascular pulsatility. In this study, we tested the hypothesis that left ventricular unloading with increasing CF LVAD flow increases myocardial flow normalized to left ventricular work. Healthy (n = 8) and chronic ischemic heart failure (IHF, n = 7) calves were implanted with CF LVADs. Acute hemodynamics and regional myocardial blood flow were measured during baseline (LVAD off, clamped), partial (2–4 L/min) and full (>4 L/min) LVAD support. IHF calves demonstrated greater reduction of cardiac energy demand with increasing LVAD support compared to healthy calves, as calculated by rate-pressure product. Coronary artery flows (p < 0.05) and myocardial blood flow (left ventricle (LV) epicardium and myocardium, p < 0.05) decreased with increasing LVAD support in normal calves. In the IHF model, blood flow to the septum, LV, LV epicardium, and LV myocardium increased significantly with increasing LVAD support when normalized to cardiac energy demand (p < 0.05). In conclusion, myocardial blood flow relative to cardiac demand significantly increased in IHF calves, thereby demonstrating that CF LVAD unloading effectively improves cardiac supply and demand ratio in the setting of ischemic heart failure.
KW - Cardiac tissue perfusion
KW - Coronary circulation
KW - Mechanical circulatory support device
KW - Rate-pressure product
KW - Regional blood flow
UR - http://www.scopus.com/inward/record.url?scp=85011691153&partnerID=8YFLogxK
U2 - 10.1007/s10439-017-1804-x
DO - 10.1007/s10439-017-1804-x
M3 - Article
C2 - 28168379
AN - SCOPUS:85011691153
SN - 0090-6964
VL - 45
SP - 1475
EP - 1486
JO - Annals of biomedical engineering
JF - Annals of biomedical engineering
IS - 6
ER -