Myocardial Infarct with Wavy Fibers

This is a myocardial infarct with wavy fibers.

You should have no trouble telling these heart fibers are dead, because the nuclei are gone. The extra-dark pink staining of the cytoplasm also indicates necrosis. As the still-beating live heart pulls at the dead portion, it makes some of the fibers crumpled or "wavy".