At 3 to 4 weeks of age the intermediate myocardial infarction shown involving a papillary muscle at low power above and medium power below have decreasing cellularity along with more prominence of collagen. Note that there are remaining normal red myocardial fibers. Cardiac biomarkers are not positive at this stage and myocardial rupture is unlikely. The degree of cardiac failure depends upon the extent of myocardial loss