Velocity Temporal Shape Affects Simulated Flow in Left Coronary Arteries.

Monitoring disease development in the coronary arteries, which supply blood to the heart, is crucial and can be assessed via hemodynamic metrics. While these metrics are known to depend on the inlet velocity, the effects of changes in the time-dependent inlet flow profile are not understood. In this study, we seek to quantify the effects of modulating temporal arterial waveforms to understand the effects of hemodynamic metrics. We expand on previous work that identified the minimum number of points of interest needed to characterize a left coronary artery inlet waveform. We vary these points of interest and quantify the effects on commonly used hemodynamic metrics such as wall shear stress, oscillatory shear index, and relative residence time. To simulate we use 1D Navier-Stokes and 3D lattice Boltzmann simulation approaches conducted on high performance compute clusters. The results allow us to observe which parts of the waveform are most susceptible to perturbations, and therefore also to measurement error. The impacts of this work include clinical insight as to which portions of velocity waveforms are most susceptible to measurement error, the construction of a method that can be applied to other fluid simulations with pulsatile inlet conditions, and the ability to distinguish the vital parts of a pulsatile inlet condition for computational fluid dynamic simulations.