<prompt> Irreversible injury to myocardium in MI occurs earliest byFew seconds10 minutes20 minutes40 minutes  <response>: Answer- C. 20 minuteshlyocardial function is more seflsithe to kchemia loss of contractility occurs within 60 seconds than myocardial structureirreversible injury occurs in 2O-40 minutes, thus myocardial necrosis begins at approximately 30 minutes after coronary occlusion 