After tissue necrosis the heart muscle turns into scar tissue at the area of infarct, myocardial cells are not able to "repair themselves" fibrinolytic therapy would have possibly been the route during the heart attack, or within the 6 hour time window if he met the specific criteria for fibrinolytic treatment, above all that was for the hospital to decide. As for know the area of infarct (dead tissue, scar tissue) can be a site for dysrhythmias. Hope this helped.
Sometimes the heart muscle is stunned from lack of oxygen that occurs with a heart attack. Sometimes providing oxygen to the deficit area can revive the heart cells.
If the heart cells are dead (necrosis) scar tissue will inhibit effective contractions and cardiac output is decreased and functionality impaired. The future probability with stem cell therapy may be a solution.