You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is The MAJOR histological feature of MI is? and explain in detail?
For 2 hours after the onset of myocardial infarction (as indicated by onset of pain or arrhythmias and shock), there are no morphologic changes in the necrotic myocardial fibers. At about 2 hours, electron microscopic changes appear (swelling of mitochondria endoplasmic reticulum, fragmentation of myofibrils). Light microscopic changes may appear in 4-6 hours but are rarely detectable with ceainty before 12-24 hours. Coagulative necrosis of the myocardial fibers is recognized by nuclear pyknosis and dark pink staining of the cytoplasm and loss of striations in the cytoplasm.Coagulative necrosis is the most common pattern of necrosis characterized by conversion of cell to acidophilic and opaque gravestone. This pattern of necrosis results most commonly from sudden severe ischemia in organs such as kidney, hea and adrenal glands. Ref: Chandrasoma P., Taylor C.R. (1998). Chapter 23. The Hea: III. Myocardium & Pericardium. In P. Chandrasoma, C.R. Taylor (Eds), Concise Pathology, 3e.