Not enough blood. Inferolateral generally refers to the location in the heart. Ischemia is insufficient blood flow to any part of the body - I am assuming you are referring to your heart in this case - so the heart muscle is not getting enough blood. This can be caused by atherosclerosis or narrowing of the blood flow in the heart.
Several. Stenosis of the artery to that area obstruction clot- plaque rupture/ disruption occasionally, embolism this is of the coronary arteries to, the heart as you asked it.