A 70 year old woman dies in a nursing home after a hea attack. The time of onset of her clinical symptomatology and the cause of death are unceain; fuhermore, the possibility of neglect is being considered. Therefore, an autopsy investigation is arranged. The forensic pathologist discovers acute thrombosis involving the posterior descending branch of the right coronary aery with resultant myocardial infarction (MI) in the posterior third of the interventricular septum. Histologically, there is coagulation necrosis with associated abundant neutrophilic infiltration. Histiocytes and lymphocytes are scanty. Which of the following is the approximate period between the onset of pain (ie, beginning of ischemic injury) and death?
Following irreversible ischemic injury, the hea (and any other organ) displays an orderly sequence of events that progresses from necrosis of parenchymal cells to inflammatory reaction, granulation tissue, and scar healing. Although ischemic injury manifests with pain almost immediately following vascular occlusion, histologic evidence of necrosis lags behind the clinical symptoms. At 1 hour after ischemia, there is no morphologic change indicative of necrosis. The first signs of necrosis appear 12 hours after irreversible ischemia: myocytes appear intensely eosinophilic and wavy, but there is no inflammatory reaction yet. Acute inflammatory cells (neutrophils) infiltrate the infarcted area beginning 1 day and peaking at approximately 2-3 days after injury. This acute inflammatory response paially overlaps with the subsequent influx of lymphocytes and histiocytes. Reabsorption of necrotic myofibers by histiocytes, as well as proliferation of small blood vessels, marks early formation of granulation tissue at around 5 days. Ref: Wyatt C., Kemp W.L., Moos P.J., Burns D.K., Brown T.G. (2008). Chapter 10. Cardiac Pathology. In C. Wyatt, W.L. Kemp, P.J. Moos, D.K. Burns, T.G. Brown (Eds), Pathology: The Big Picture.
1 hour
12 hours
2 days
5 days