Effects of the left ventricular viscosity on a failed heart: An in-silico analysis

Abstract

Cardiac chambers are often represented by a time-varying elastance model in hemodynamic simulation. However, myocardium also has viscosity in the real world. To evaluate the effects of viscosity of myocardium on hemodynamics, a computational models of cardiovascular system was developed with a time-varying visco-elastance chamber model based on the Kelvin-Voigt viscoelasticity model and a modified 3-element Windkessel vascular model. To simulate a failed heart, the left ventricular end-systolic elastance (Ees) was varied from 3.0 to 1.5 mmHg/ml. An addition of viscosity on the left ventricular elasticity increased the stressed blood volume (SBV) to maintain mean arterial pressure and decreased the left ventricular ejection fraction (LVEF). The impacts of viscosity on SBV and LVEF in the failed heart with Ees of 1.5 mmHg/ml were larger than those in the normal heart with Ees of 3.0 mmHg/ml. The left ventricular viscosity may largely affect hemodynamics of heart failure.