Computational Model of a Left Ventricle: Showing the Effects of Inertia on Cardiac Dyssynchrony

In an effort to research heart failure, a leading cause of death in the industrialized world, this research team has developed a segmented lumped parameter model of the left ventricle. The computations model developed focuses on dyssynchrony, a heart condition where some regions of the heart vary significantly in properties like internal muscle resistance, mass, or elastance. Inertial effects are often assumed as negligible by cardiovascular models. One primary function of this model is to investigate inertial effects as they relate to mechanical cardiac dyssynchrony. An added dimension of this analysis is to observe the thermodynamics of the cardiac cycle as one long term indicator of heart failure. This model was developed using an electrical analog to the hemodynamic system. The parameters of a heart wall segment were represented by resistance, inductance, and capacitance. The calculations were done using state space and programmed into Matlab for simulation. This research shows waveforms of volume outputs as well as pressure volume loops for synchronous waveforms as well as dyssychronous waveforms caused by a time delay, varied resistance, varied elastance, and varied mass. The variation seen in the mass dyssynchrony waveforms suggest that inertial effect may be a significant factor in modeled cardiovascular systems