Myocardial Ischemia Present the moment there is a decrease of complete absence of blood supply to myocardial tissue Mild or moderate anoxia can be tolerated for a short time by the cardiac cells without greatly affecting their function. Upon return of adequate blood flow and reoxygenation, these cells usually return to a normal or near normal condition

Myocardial Injury If ischemia is severe or prolonged, the anoxic cardiac cells sustain damage and stop functioning normally, unable to contract or generate or conduct electrical impulses properly. Damage cells still remains reversible so that the injured cells remain viable, and salvageable for some time. Cells may return to normal or near normal after the return of adequate blood flow and reoxygenation.

Myocardial Infarction Severe myocardial ischemia continues because of continued complete absence of blood supply, the anoxic cardiac cell will sustain irreversible injury and die Necrosis is present After occlusion of a CA the myocardium evolves through various stages and degrees of severity of impairment.

Acute Coronary Syndromes Silent Ischemia –ST depression with or without pain Stable Angina –Exertion induced angina that remains unchanged Unstable Angina –New onset of angina, increase of existing angina, angina at rest > 20 minutes Acute MI –Plaque rupture with thrombus formation Sudden Cardiac Death –V-Tach or V-fib is the most common cause of 80% of population –Asystole or EMD is the cause of the other 20%

Acute Myocardial Infarction After occlusion of a CA, the myocardium evolves through various stages and degrees of severity of impairment: Myocardial Ischemia-zone of ischemia Myocardial Injury-zone of injury Myocardial Infarction-zone of infarction (dead tissue)