The Influence of Left Ventricle and Aorta Interactions on the Coronary Blood Flow Using One-Dimensional Model of Hemodynamics and Wave Propagation in the Entire Circulatory System

Abnormal left ventricle (LV) and aortic coupling can impact coronary hemodynamics through different mechanisms including changes in arterial wave reflection, coronary resistance, and coronary wave dynamics. Such abnormal interactions can lead to a decrease in coronary blood flow and an increase in LV workload. Subsequently, this could create a mismatch between myocardial oxygen delivery and consumption, manifesting as chronic myocardial ischemia. LV contractility, heart rate (HR), and aortic stiffness are the main determinants of LV-aortic coupling and aortic hemodynamics. In this study, we employed an in-silico one-dimensional model of the entire circulatory system coupled with a four-chamber heart elastance model to investigate the effects of LV-aortic coupling on coronary hemodynamics. Numerical simulations were conducted using a high-order pseudo-spectral Fourier continuation method. We investigated how various factors influencing aortic wave dynamics (such as aortic stiffness and HR) and cardiac dynamics (including LV contractility and end-diastolic volume) affect coronary blood flow. Particular attention was given to conditions such as heart failure with preserved ejection fraction, which is primarily associated with impairment in LV-Aortic coupling.