Case 5 -
Acute Myocardial Infraction of 3-5 Days Duration on a Background of Older Myocardial Infraction
Christopher Milroy, The Ottawa Hospital, Ottawa, ON
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53 year old male. Had a confrontation with the police. He was taken to a police station where he was declared fit for interview by a medical officer and released after a few hours detention. He subsequently complained of back pain, collapsed and could not be resuscitated. Can you date the lesions(s) seen on microscopy ?
Pertinent Laboratory Data:
Toxicology was negative Vitreous biochemistry was unremarkable
This case involved a 53 year old man who was involved in a incident with the police. He was sprayed
in the face with CS spray, a noxious and acutely stressing agent. Four days later he collapsed and died
unexpectedly. He was a diabetic. There was a history of chest pain before the event, that was provided
before the autopsy but this was subsequently disputed by his family. At autopsy there was a macroscopic
infarct and coronary artery thrombosis Pathological/Microscopic Findings and any Immunohistochemical or
Other Studies: There is an acute myocardial infarct on a background of older myocardial infraction. The
dating of the acute infarct suggests it is 3-5 days old. This time span straddles the event.
The differential diagnosis in this case relates to whether the acute infarct dates from around the
time of the infarct or was older. This timing is central to the issue of whether the use of CS spray
precipitated the acute infarct, as the use of the CS spray was contoversial. If a noxious agent
precipitates an acute myocardial infarct and that act was illegal, then the possibility of homicide by
natural causes is raised.
Acute Myocardial Infraction of 3-5 Days Duration on a Background of Older Myocardial Infraction.
Acute myocardial infarction (AMI) is a very common entity and can raise a number of Forensic
Pathology questions. The presence of acute myocardial infarction does not necessarily mean the manner of
death is natural. Use of stimulant drugs of abuse may precipitate AMI and their presence would mean the
manner of death would be an accident. Where an unlawful act causes an AMI then the possibility of
homicide by natural causes is raised.
More common than AMI at autopsy in sudden death is macroscopic stable coronary artery disease. In
these cases the presence of other changes may help determine whether the death is cardiac or not.
Changes such as acute plaque hemorrhage and early microscopic changes may help, but are often absent.
Timing of myocardial infarction is, in reality not that common a forensic issue but may be important
in accidents and homicides. The changes allow a likely time range, but it is not possible to be specific
about timing based on pathology alone, but rather a range should be given. However a basic timing
schedule on hematoxylin and eosin staining is:
Most cases of sudden death with ischemic heart disease occur before histological changes are evident.
- 0-12 hours - No significant changes
- 12-24 hr myocyte eosinophilia,
- 24 hr - neutrophil infiltrate at periphery
- 36 hr - Neutrophil karyorrhexis starts
- 3-5 dyas - Myocytes lack nuclei and banding. Prominent karyorrhexis
- 4-5 days - Macrophages with hemosiderin start
- 7 days - Granulation tissue starts to form
Review of the Literature/Treatment Options:
Precipitating events of acute myocardial are important for the forensic pathologist as they may be
central to legal proceedings.
Often there is stable coronary artery disease present at autopsy. Less often there is obvious acute
Establishing the precipitating event requires an analysis of history, cardiac findings and
toxicological analysis. The epidemiological studies on earthquakes, the Iragi missile attacks on Israel
and watching sporting events have shown that emotional stress as well as physical exertion can
precipitate acute myocardial infraction. Studies on stimulant drugs have also shown these can precipitae
acute myocardial infraction.
Ischemic heart disease and acute myocardial infarction remain major causes of sudden death. The
manner of death in the presence of stable ischemic heart disaese or acute myocardioal infarction cannot
simply be dismissed as natural, as use of drugs or physical or emotional stressors may change the manner
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