Stenosis severity and heart rate effects on left coronary artery hemodynamics and myocardial oxygen balance: A comprehensive assessment using pressure gradient

Abstract

The estimation of pressure drop across stenotic arteries can provide valuable information about the hemodynamic features. Nevertheless, the temporal behavior of pressure in stenotic arteries is not well reported for realistic pulsatile flows. This research investigates the pressure drop across a left coronary artery model for different degrees of stenotic severity and heart rates. The zones prone to further atherogenic degeneration are identified using time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). A unique attempt has been made to quantify the effect of stenosis severity and elevated heart rate on coronary perfusion pressure (CPP) and endocardial viability ratio (EVR), which is an indicator of myocardial oxygen supply-demand balance. We have predicted reductions in both CPP and EVR as stenosis severity increases. The aforementioned metrics exhibit a notable drop when confronted with a moderate stenosis at an increased heart rate, implying that the hemodynamic consequences of a moderate stenosis during an elevated heart rate may be comparable to those of a severe stenosis during a state of rest. The current computational investigation has the potential to reduce the need for in vivo hemodynamic assessments of stenosis. In addition, the wall shear stress-based mechanical parameters, such as TAWSS and OSI, can indicate the atherogenic and thrombogenic regions in the stenosed vessels.