Table 5.
Diagnostic pitfalls in post-mortem diagnosis of myocardial ischemia
| Diagnostic method | Finding | Possible pitfalls |
|---|---|---|
| Histological examination | Contraction bands | Marker for ischemia/reperfusion (including border zones of ischemic infarctions), and other types of myocardial injury |
| Histopathological timing of ischemia/infarction |
Evolution may be affected by several variables (individual heterogeneity in the response to injury, repair and inflammatory response, size of infarction and medications that affect inflammation and wound healing, collateral circulation) Resuscitation trauma and autolysis can mimic histologic features of early MI (false positivity). |
|
| Immunohistochemistry | Some antibodies may have low sensitivity/specificity for early ischemic necrosis |
Stains also other forms of myocardial injury; influenced by autolysis and post-mortem interval; probably early detection, but exact time of onset of immunopositivity not exactly known Can occur in cases with long post-mortem interval |
| Nitro blue tetrazolium (NBT) staining | Diffuse or spotty discoloration | Unstained areas can occur in cases of long post-mortem interval, resuscitation attempts, sepsis, technical failures (see text) |
| Post-mortem imaging | Calcifications in PMCT |
Heavily calcified coronaries can be observed in stable plaques, not necessarily related to acute coronary syndromes and MI Non-calcified coronaries or spotty calcifications of coronaries might be observed in eroded plaques |
| Perfusion of coronaries in PMCTA |
Difficult to discriminate thrombus from post-mortem clot Some thrombosed coronary arteries (eroded plaques) might be perfused (mural thrombi) Difficult to evaluate the perfusion of heavily calcified coronaries |
|
| Interstitial oedema in PMMR | Also positive in other forms of injury, including CPR, and may occur as post-mortem alteration | |
| Increased enhancement in PMCTA | Can be influenced by resuscitation and post-mortem alteration | |
| Cardiac biomarkers | Increased of hs-TnT in serum |
Serum value can be influenced by post-mortem alteration Cut-off of vital myocardial injury unknown |