title: Prediction of hemodynamics under left ventricular assist device.
abstract: Left ventricular assist device (LVAD) saves lives in patients with severe left ventricular (LV) failure. However, predicting how much LVAD boosts total cardiac output (CO) remains difficult. This study aimed to develop a framework to quantitatively predict the impact of LVAD on hemodynamics. We adopted the circulatory equilibrium framework and incorporated LVAD into the integrated CO curve to derive the circulatory equilibrium. In anesthetized dogs, we ligated left coronary arteries to create LV failure and inserted a centrifugal pump as LVAD. Using CO and right (PRA) and left atrial pressure (PLA) measured before LVAD support, we predetermined the stressed volume (V) and logarithmic slope of right heart CO curve (SR). Next, we initiated LVAD at maximum level and then decreased LVAD flow stepwise while monitoring hemodynamic changes. We predicted LVAD-induced CO and PRAfor given PLAfrom the predetermined SRand V and compared with those measured experimentally. The predicted CO [r2= 0.907, SE of estimate (SEE) = 5.59 ml·min-1·kg-1, P < 0.001] and PRA(r2= 0.967, SEE = 0.307 mmHg, P < 0.001) matched well with measured values indicating the validity of the proposed framework. We further conducted simulation using the validated framework to analyze the impact of LVAD on PRAunder various right ventricular (RV) functions. It indicated that PRAis relatively insensitive to changes in RV end-systolic elastance or pulmonary arterial resistance, but sensitive to changes in V. In conclusion, the circulatory equilibrium framework predicts quantitatively the hemodynamic impact of LVAD. This knowledge would contribute to safe management of patients with LV failure undergoing LVAD implantation.
  Hemodynamic response to left ventricular assist device (LVAD) has not been quantitatively investigated. This is the first report of quantitative prediction of the hemodynamics on LVAD using circulatory equilibrium framework. The validated framework allows us to simulate the impact of LVAD on right atrial pressure under various right ventricular functions.
authors: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors: Takamori
authors: T
authors: Kakino
authors: Department of Therapeutic Regulation of Cardiovascular Homeostasis, Center for Disruptive Cardiovascular Medicine, Kyushu University, Fukuoka, Japan; and.
authors: Keita
authors: K
authors: Saku
authors: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors: Takafumi
authors: T
authors: Sakamoto
authors: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors: Kazuo
authors: K
authors: Sakamoto
authors: Department of Therapeutic Regulation of Cardiovascular Homeostasis, Center for Disruptive Cardiovascular Medicine, Kyushu University, Fukuoka, Japan; and.
authors: Takuya
authors: T
authors: Akashi
authors: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors: Masataka
authors: M
authors: Ikeda
authors: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors: Tomomi
authors: T
authors: Ide
authors: Collaborative Research Institute of Innovative Therapeutics for Cardiovascular Diseases, Center for Disruptive Cardiovascular Medicine, Kyushu University, Fukuoka, Japan.
authors: Takuya
authors: T
authors: Kishi
authors: Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan.
authors: Hiroyuki
authors: H
authors: Tsutsui
authors: Department of Therapeutic Regulation of Cardiovascular Homeostasis, Center for Disruptive Cardiovascular Medicine, Kyushu University, Fukuoka, Japan; and sunagawa@cardiol.med.kyushu-u.ac.jp.
authors: Kenji
authors: K
authors: Sunagawa
mesh_terms: D000818:Animals; D062185:Atrial Pressure / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology*; D003331:Coronary Vessels / Q000601:surgery; D004285:Dogs; D005260:Female; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006439:Hemodynamics; D008026:Ligation; D008297:Male; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy*; D016278:Ventricular Function, Right / Q000502:physiology*
keywords: cardiac output curve; circulatory equilibrium; hemodynamics; left ventricular assist device; venous return surface