Simulation of dilated heart failure with continuous flow circulatory support.
Lumped parameter models have been employed for decades to simulate important hemodynamic couplings between a left ventricular assist device (LVAD) and the native circulation. However, these studies seldom consider the pathological descending limb of the Frank-Starling response of the overloaded ventricle. This study introduces a dilated heart failure model featuring a unimodal end systolic pressure-volume relationship (ESPVR) to address this critical shortcoming. The resulting hemodynamic response to mechanical circulatory support are illustrated through numerical simulations of a rotodynamic, continuous flow ventricular assist device (cfVAD) coupled to systemic and pulmonary circulations with baroreflex control. The model further incorporated septal interaction to capture the influence of left ventricular (LV) unloading on right ventricular function. Four heart failure conditions were simulated (LV and bi-ventricular failure with/without pulmonary hypertension) in addition to normal baseline. Several metrics of LV function, including cardiac output and stroke work, exhibited a unimodal response whereby initial unloading improved function, and further unloading depleted preload reserve thereby reducing ventricular output. The concept of extremal loading was introduced to reflect the loading condition in which the intrinsic LV stroke work is maximized. Simulation of bi-ventricular failure with pulmonary hypertension revealed inadequacy of LV support alone. These simulations motivate the implementation of an extremum tracking feedback controller to potentially optimize ventricular recovery.
Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America.
Yajuan
Y
Wang
Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America.
Natasha
N
Loghmanpour
University of Bern, Bern, Switzerland.
Stijn
S
Vandenberghe
Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America ; Mathematics, Universidade Federal do Maranhão, Maranhão, Brazil.
Antonio
A
Ferreira
Cardiovascular Innovation Institute, University of Louisville, Louisville, Kentucky, United States of America.
Bradley
B
Keller
Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, United States of America.
John
J
Gorcsan
Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America.
James
J
Antaki
D001794:Blood Pressure / Q000502:physiology; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016022:Case-Control Studies; D003198:Computer Simulation; D003326:Coronary Circulation / Q000502:physiology*; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006353:Heart-Assist Devices; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000503:physiopathology; D008955:Models, Cardiovascular; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D014463:Ultrasonography; D016277:Ventricular Function, Left / Q000502:physiology