Wiktionary
n. A degenerative change (often reversible) that occurs to myocytes upon myocardial strain.
Wikipedia
Myo cytolysis refers to a degenerative change (often reversible) that occurs to myocytes upon myocardial strain. This phenomenon tends to occur when neighboring cardiac muscle loses its ability to contract (i.e. in ischemia or infarction). The remaining viable muscles, as the result, strain to compensate for the loss of other muscles in order to deliver the necessary cardiac output. During the process, myocardial cells are stretched and stressed to produce new contractile elements.
The histopathology of myocytolysis typically present with lighter stained cytoplasm (with clear patches), which is the result of presence of glycogen in place of contractile elements in the cytoplasm.