A coroner or medical examiner serves as a medical-legal investigator responsible for determining the cause and manner of death, especially in cases that are sudden, unexpected, or unattended. While heart attacks are a common cause of death, their accurate determination involves a detailed and systematic investigation. This comprehensive approach ensures that all potential factors contributing to death are considered, moving beyond initial assumptions to a scientifically supported conclusion.
Initial Investigation and External Clues
The process of determining a heart attack begins with a thorough scene investigation. The coroner or medical examiner documents the environment, noting medications, medical devices, or other pertinent items that offer insights into the deceased’s health or the circumstances of death. Reviewing the deceased’s medical history is also significant, as it can reveal pre-existing conditions such as coronary artery disease, hypertension, or diabetes, which increase the risk of a heart attack.
An external examination of the body identifies any obvious signs of trauma or illness. While external findings alone are rarely conclusive for diagnosing a heart attack, they can sometimes indicate underlying conditions or rule out other causes of death. For example, surgical scars from previous heart procedures, like bypass grafting or pacemaker implantation, suggest a history of cardiovascular disease.
Internal Examination of the Heart
During an autopsy, the internal examination of the heart provides macroscopic evidence of a heart attack. The body is opened, and organs are systematically inspected, with particular attention paid to the heart’s size, weight, and overall condition. Coronary arteries are meticulously examined for the presence and degree of atherosclerosis, and for any signs of thrombus formation or plaque rupture. Atherosclerosis in the coronary arteries is a frequent finding in sudden deaths, with varying degrees of blockage often observed.
The heart chambers, valves, and surrounding tissues are also carefully inspected for damage. This includes looking for areas of pallor or hemorrhage in the heart muscle, which can indicate a recent myocardial infarction. Evidence of scarring from a previous heart attack is also noted, as this can provide a timeline of cardiac events. Gross changes like dark mottling in the myocardium may only become visible after 12 hours following the onset of a heart attack.
Microscopic Analysis and Supporting Tests
Microscopic examination, or histopathology, plays an important role in confirming a heart attack and dating the event. Tissue samples from the heart are taken during the autopsy, processed, and then examined under a microscope by pathologists. At a cellular level, pathologists look for necrotic myocardial cells, inflammatory infiltrates, and signs of early healing, which can help determine when the heart attack occurred. For instance, loss of nuclei in myofibers and polymorphonuclear leucocyte infiltration are histological criteria used to diagnose early myocardial infarction, especially within 6 to 42 hours.
Toxicology screening is performed to rule out drugs or poisons that could have caused or contributed to cardiac arrest, or mimicked symptoms of a heart attack. This testing involves analyzing biological fluids for various substances, helping to differentiate a natural cardiac event from other causes of death. Specialized histochemical stains like Triphenyl Tetrazolium Chloride (TTC) can detect early myocardial infarction, sometimes within 5-6 hours, by highlighting metabolically inactive tissue. This technique can reveal infarcts that are not yet visible through gross or routine microscopic examination, minimizing false negatives in sudden death cases.
Formulating the Final Determination
The coroner synthesizes all collected information to arrive at a definitive conclusion regarding the cause and manner of death. This involves integrating findings from the scene investigation, the deceased’s medical history, the external and gross internal examinations, microscopic analysis, and toxicology results. The process requires careful consideration to rule out other potential causes of death, ensuring the attribution to a heart attack is scientifically sound.
The final determination includes both the “cause of death,” such as acute myocardial infarction, and the “manner of death,” which is typically classified as natural in such cases. This investigation ensures accuracy in official records and provides clarity for families and legal purposes.