Even though atherosclerosis is highly linked to heart attacks and strokes which are two leading causes of death around the world, its mechanisms by which it forms, develops, and triggers the onset of myocardial infarction are not fully understood. In this study, we simulated blood flow in an artherosclerotic coronary artery to study the effect that atheromas have on the blood flow physics. Particularly, we take a deeper look at the temporal and spatial distribution of wall shear stresses (WSS) at locations that are more prone to trigger cell detachment that can lead to myocardial infarction. The idealized coronary artery was created using human anatomical dimensions. Simulations were performed under laminar flow conditions, density = 1060 kg/m³, and viscosity = 3.5 centipoise. We applied a physiological velocity waveform at the inlet and a zero relative-pressure condition at the outlet. No slip boundary conditions were prescribed at the coronary artery walls. The results showed that coronary arteries afflicted with atherosclerosis cause significant temporal and spatial variability of axial shear stress. Upstream from the occlusion, shear stress is mostly positive due to the unidirectional flow. After the occlusion, shear stresses oscillate between positive and negative values. This demonstrates that ECs downstream from the occlusion are severely exposed to WSS oscillations that in combination with specific ranges of WSS set the stage for cell detachment.