Hemodynamic Endpoints

LV hemodynamics was characterized in terms of the mean in-plane velocity vector field (V¯12) and the mean out-of-plane vorticity (Ω¯12) field defined as:

and

respectively. Turbulence characteristics were quantified in terms of turbulence kinetic energy (TKE) and Reynolds shear stress (RSS) defined as:

and

respectively.

To investigate the possible impact of AoSA abnormalities on the WSS environment in DSS-prone LV anatomies, WSS characteristics were captured in the N-LV and S-LV models over a region on the septal wall susceptible to DSS lesion formation (see Figure 1A). This region was discretized into three equally spaced 2-mm sub-regions: the crest of the septum (site 2), and the sites immediately above and below this location (site 1 and 3, respectively). WSS characteristics consisted of the instantaneous ensemble-averaged WSS component τ¯12, the temporal shear magnitude (TSM), the temporal shear gradient (TSG) and the oscillatory shear index (OSI) defined as:

and

respectively, where T is the cardiac period. The TSM and TSG characterize the time-averaged magnitude and temporal gradients of the WSS over one cardiac cycle, respectively, while the OSI quantifies the oscillatory nature of the WSS signal (OSI = 0: purely pulsatile/unidirectional; OSI = 0.5: purely oscillatory/bidirectional).