What is it?
MI is defined as the irreversible death or necrosis of myocardial tissue due to an inadequate coronary blood supply. MI is nearly always due to a thrombus in the coronary artery. Irreversible cell death begins within 20 minutes of the cessation of blood flow through the coronary artery.
The amount of damage or necrosis depends on whether the occlusion is complete or partial, the duration of the occlusion, where in the coronary artery the blockage occurred, and the amount of collateral blood flow to the affected area of the myocardium.