A 60 year old male presented with acute chest pain of 4 hours duration. Electrocardiographic examination revealed new Q wave with ST segment depression. He succumbed to his illness within 24 hours of admission. The heart revealed presence of a transmural haemorrhagic area over the septum and anterior wall of the left ventricle. Light microscopic examination is most likely to reveal -
The patient in the question succumbed to myocardial infarction after about 28 hours of the attack. After twenty-four hours of the attack light microscopy shows coagulative necrosis of myofibrils with loss of nuclei and striations along with an interstitial infiltrate of neutrophils. For details, see the table of morphological changes of MI in text.
Edema in between normal myofibres
Necrotic myofibres with presence of neutrophils
Coagulative necrosis of the myocytes with presence of granulation tissue
Infiltration by histiocytes with haemosiderin laden macrophages