Image 1: Note the contraction bands in the center of the field.
Image 2: A closer look.
Image 3: A different case with contraction bands.
Image 4: These bands represent hypercontracted sarcomeres.
Contraction bands are another feature of early ischemic damage, in addition to hypereosinophilia, loss of striations and wavy fiber change. Contraction bands are associated with reperfusion injury and the mechanism is thought to be calcium overload. They are most likely seen at the margin of the infarct.