Continuous-Flow Left Ventricular Assist Device Support Improves Myocardial Supply:Demand in Chronic Heart Failure.
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.
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, 40202, USA.|Department of Bioengineering, University of Louisville, Louisville, KY, 40202, USA.
Kevin G
KG
Soucy
Division of Cardiovascular Surgery, Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA, 19104, USA.
Carlo R
CR
Bartoli
Department of Bioengineering, University of Louisville, Louisville, KY, 40202, USA.
Dustin
D
Phillips
Department of Bioengineering, University of Louisville, Louisville, KY, 40202, USA.
Guruprasad A
GA
Giridharan
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, 40202, USA.
Michael A
MA
Sobieski
Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, KY, 40202, USA.
William B
WB
Wead
Dowling Consulting, PSC, Louisville, KY, 40202, USA.
Robert D
RD
Dowling
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, 40202, USA.
Zhongjun J
ZJ
Wu
Division of Cardiovascular Disease and Comprehensive Cardiovascular Center, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Sumanth D
SD
Prabhu
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, 40202, USA.|Department of Bioengineering, University of Louisville, Louisville, KY, 40202, USA.
Mark S
MS
Slaughter
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Innovation Institute, University of Louisville, Louisville, KY, 40202, USA. steven.koenig@louisville.edu.|Department of Bioengineering, University of Louisville, Louisville, KY, 40202, USA. steven.koenig@louisville.edu.
Steven C
SC
Koenig
D000818:Animals; D002417:Cattle; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000502:physiology; D006321:Heart / Q000502:physiology; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006439:Hemodynamics; D008297:Male; D017202:Myocardial Ischemia / Q000503:physiopathology / Q000628:therapy; D016277:Ventricular Function, Left
Cardiac tissue perfusion; Coronary circulation; Mechanical circulatory support device; Rate-pressure product; Regional blood flow