Některé možnosti diagnostiky časných akutních ischemických změn srdečního svalu u náhlých úmrtí
Úvod: Ischemická choroba srdeční patří mezi nejčastější onemocnění a značnou měrou se podílí na mortalitě naší populace (v letech 1995–2003 52–56,2 %). Náhlá úmrtí tvoří téměř 2/3 pitev, se kterými se soudní lékaři setkávají, a z nich více než 50 % je způsobeno ICHS. Proto je její diagnostika, a to zejména akutního infarktu myokardu, tak důležitá. Základním diagnostickým kritériem akutního infarktu myokardu je dle společné definice Evropské kardiologické společnosti a American College of Cardiology z roku 2000 pozitivita biochemických ukazatelů nekrózy srdečního svalu. Obecně platí závislost mezi aktivitou enzymů a množstvím poškozených buněk. Již asi 10 let se v odborné literatuře objevují práce, které doporučují využívat stanovení aktivity či koncentrace těchto biochemických ukazatelů i při diagnóze časných fází infarktu myokardu post mortem.
Metody: Stanovovali jsme koncentrace myoglobinu, kreatinkinázy a troponinu I v krvi a v perikardiální tekutině zemřelých náhlou a násilnou smrtí. Soubor, který tvořilo 71 zemřelých, byl rozdělen do dvou skupin, první skupina (38 případů) byla tvořena zemřelými na akutní infarkt srdečního svalu (byl makroskopicky patrný nebo byla zjištěna ložiskově snížená aktivita SDH při histoenzymatické makroreakci v Šiklových řezech při výrazném zúžení či uzávěru věnčitých tepen a vyloučení jiné příčiny smrti). Zbylých 33 případů (tzv. non-IM smrti) tvořily 4 případy srdečního selhání, 6 případů intracerebrálního krvácení, 5 případů plicní embolie, 5 případů udušení (čtyřikrát oběšení, jednou traumatická asfyxie), tři případy zhmoždění mozku, dva případy otravy CO, dva případy utonutí, po jednom případu otravy kyanidy, otravy alkoholem, smrti vykrvácením, epilepsie, bronchopneumonie a hyperglykemického komatu.
Výsledky: Kreatinkináza a myoglobin v krvi a v perikardiální tekutině a troponin I v perikardiální tekutině byly zvýšeny ve všech případech jak u IM, tak u non- IM smrtí, statisticky se nelišily ani jejich hladiny. Troponin I byl v krvi zvýšen v 87 % u IM a v 91 % u non-IM smrtí, rozdíl není statisticky významný, rovněž koncentrace se statisticky nelišily.
Závěr: Nepodařilo se nám prokázat možné využití stanovení koncentrací myoglobinu, kreatinkinázy a troponinu I v krvi a perikardiální tekutině při diagnostice infarktu myokardu.
Introduction: Ischaemic heart disease is the leading cause of death in industrialised countries. Sudden death accounts for approximately 2/3 of autopsies in forensic medicine, which is why the accurate diagnosis of IHD and first of all acute myocardial ischaemia is so important. On certain occasions in forensic medical practice it is difficult to diagnose AMI from morphological observation alone. In such cases, complementary diagnostic techniques, such as the determination of biochemical markers of the necrosis of the heart muscle (myoglobin, troponin I and creatine kinase) in cadaver fluids, take on special importance, so we decided to test the diagnostic evaluation of postmortem cTnI, myoglobin and creatine kinase determination in serum and pericardial fluid. Recently, cardiac troponins have gained attention as very specific markers of myocardial cell injury, and the European Society of Cardiology and the American College of Cardiology have suggested that these proteins should be preferred markers for the diagnosis of the necrosis of heart muscle.
Methods: We studied 71 cadavers, which were divided into 2 groups. The first group (38 cases) consisted of people where the acute myocardial infarction was the only cause of death (the myocardial lesion could be easily detected by macroscopic examination or by formazan test, other causes of death were excluded and the constriction or obturation of the coronary arteries was detected). The second group (non-AMI deaths) was formed by 4 cases of cardiac failure, 6 cases of intracerebral haemorrhage, 5 cases of pulmonary embolism, 7 cases of asphyxia (4 hangings, 1 traumatic asphyxia, 2 drownings), 3 cases of brain contusion, 2 cases of carbon monoxide poisoning, 1 case of cyanide poisoning, 1 case of alcohol poisoning, 1 case of epilepsy, 1 case of bronchopneumonia, 1 case of hyperglycaemic coma and 1 case of exsanguination.
Results: The values of creatine kinase and myoglobin were increased in all cases (100%) of AMI-deaths and non-AMI deaths in blood and pericardial fluid and there was no statistically significant difference between these groups. Troponin I was increased in all cases of both groups in pericardial fluid, and again there was no significant difference in concentration between both groups. In blood, troponin I was increased by 87% in the group of AMI deaths and in 91% of non-AMI deaths. There was no significant statistical difference between the groups and there was no difference in concentration either.
Conclusion: We did not find a statistically significant difference in pericardial fluid or in serum for cTnI, CK-MB and myoglobin between the group of AMI deaths and the group of non-AMI deaths and we cannot confirm the diagnostic efficacy of these biochemical markers in the postmortem diagnosis of acute myocardial infarction.
heart disease (IHD) is a general term for illnesses which have in common
ischaemia of the myocardium based on a pathological process in the
coronary arteries. The term “ischaemia of the myocardium” has a broad
range; it includes additional aspects when the inadequate oxygen supply has
a noncoronary origin (for example reduction of the blood transport capacity
for oxygen, depression of the blood pressure, pathologically increased
coronary bed ensures a supply to the myocardium of metabolic substrates
(the crucial one is the supply of oxygen) and the recruitment of metabolic
waste. The contractility and relaxation of the myocardium depends on adequate
coronary flow, reduction of contractility appears with the restriction of
perfusion about 10–20%. (4) There is already a high arteriovenous
difference (75%) in the coronary circulation under normal resting conditions
(2) and so it is not possible to increase the release of oxygen markedly under
load. The greater metabolic requirements must be covered by increased coronary
imbalance between metabolic necessity and perfusion possibilities could be
increased requirements of the myocardium;
ireduced perfusion of the coronary bed;
a combination of increased requirements
and reduced perfusion (the most common). (4)
is a clinical term for situations with different aetiopathogenesis but
with the same consequence – the critical reduction of the blood flow through
the coronary system. The basis of the defect of perfusion can be organic
(atherosclerotic lesion, thrombosis, embolism, arteritis, coronary fistula or
dissection) or functional (coronary spasm). Most often we see
a combination of various pathogenetic factors, usually atherosclerotic
plaque complicated by thrombosis or spasm).
Clinical classification of IHD: (4)
unstable angina pectoris
acute myocardial infarction
sudden coronary death
unmanifested ischaemia of the myocardium
IHD manifested by insufficiency of the myocardium
IHD manifested by cardiac arrhythmia
infarction of the myocardium (MI) is the most important form of IHD. It is
a locus of acute ischaemic necrosis of the myocardium caused in most cases
by the thrombotic closure of an atherosclerotic coronary artery. This is the
most common cause of death in industrialised countries). (5)
primary reason for the onset of MI is:
an unstable atherosclerotic plaque (that is
a plaque with exposed subendothelium);
an occluding thrombus;
critical stenosis closing the lumen partially or completely;
spasm of the coronary artery (ordinarily
imposed on atherosclerotic plaque).
there are factors which can contribute to the expansion of the focus of MI:
increasing metabolic requirements of the
myocardium (hypertension, tachycardia).
6% of all patients and almost 25% of patients with MI younger than 35 years do
not have any detectable signs of coronary atherosclerosis by coronarography or
autopsy and they do not have any risk factors of atherosclerosis except for
smoking (9). The reason for MI in these patients may be protracted spasm,
exceptionally embolism of a coronary artery, sometimes inflammatory
changes, trauma, post-thrombotic conditions, congenital anomaly of the coronary
arteries, the acute onset of a disproportion between oxygen supply and
consumption in the myocardium (CO poisoning, aortic stenosis, cocaine abuse)
infarct of the myocardium can affect any part of the heart, an infarct in the
left ventricle is the most often and clinically most consequential; infarct in
the right ventricle appears together with lesions of the posterior wall;
infarct in the atria is usually silent but it can manifest as faults of
formation and conduction of impulses.
cells of the myocardium can survive about 20–30 minutes with the ability to
recover completely by restoring the oxygen supply after the closure of
a coronary artery. The progression of necrosis from the endocardium to the
epicardium and from the centre to the periphery of the coronary artery basin
lasts 4–12 hours (usually about 6 hours, exceptionally 24 hours). The ability
to contract of the ischaemic myocardial part disappears progressively for
several seconds after total closure of a coronary artery. Hypokinesis
(depression of contractions) is the least severe grade of lesion, akinesis is
the more severe one (extinction of contractions) and dyskinesis is the most
severe grade (extinction of contractions and passive paradoxical systolic bulge
of the affected region).
to the European Society of Cardiology and The American College of Cardiology,
the basic clinical diagnostic criterion of acute MI (AMI) is the positivity of
the biochemical markers of myocardial necrosis (9). Generally the relation
between the activity of the enzymes and the amount of cellular damage is valid.
determination of creatine-kinase(CK) activity and its specific
myocardial fraction (CK-MB) is one of the most specific tests. The normal
values of CK are 0.2–3.2 μkat/l, CK-MB up to 0.4 μkat/l. At least a double increase is required for
the positive diagnosis of AMI. Problems with diagnosis can occur from
simultaneous contusion of skeletal muscles (for example after cardiopulmonary
resuscitation – CPR, cardioversion) or after prolonged exercise, from myopathy
next specific sign of necrosis is the rapid increase of the concentration of
myoglobin and troponin in the serum. The increased value of myoglobin lasts for
1–2 days only, the value of troponin about 1 week. The normal value of
myoglobin is 5–70 μg/l, but an increased
value is not just specific for myocardial lesions, we can find it in lesions of
the skeletal muscles and in renal insufficiency.
are regular proteins supervising calcium mediated interaction between actin and
myosin. Cardiac forms of these proteins (cTnI a cTnT) are products of
specific genes, which occur only in the heart. Their increase is mostly proof
of “minimal cardiac necrosis”. Normal values of troponin T are up to 0.05 μg/l, of troponin I up to 0.5 μg/l. False positive results are found in dialysed
patients with advanced renal failure. Almost 29% of these patients show
a positive troponin T value without a simultaneous lesion of the
myocardium. We do not see an increase of troponin I so often, but its
value increases in patients with serious heart congestion, probably in connection
with myofibrillar degeneration and in patients with hepatic cirrhosis with an
alcoholic aetiology. Acute lesions of skeletal muscles do not have any
influence on increasing values of troponins (Table 1, Graph 1).
earliest macroscopically apparent pathologic-anatomical changes arise after 6
hours of ischaemia, usually even later. Non-specific changes (paleness, red and
bluish cyanosis, “boiled look”, thinning of the left ventricular wall in the
area of the infarct) are apparent usually after 12–18 hours. The completely developed
yellow-coloured coagulative necrosis with haemorrhagic border can be seen after
focus of ischaemia becomes greyer at the end of the first week; this is caused
by gradual substitution of necrotic muscle by granular tissue. Complete cicatricose
transformation forms over 6–8 weeks, it depends on the size of the infarct.
early diagnosis of myocardial infarct after 3–6 hours is possible by the use of
histoenzymatic reaction (macroreaction) with nitro-blue-tetrazolium on
cross-section of the ventricles of the heart; necrotic myocardium loses its
enzymes (mainly dehydrogenases) and so the resulting colour of the necrotic
tissue after the reaction is different in comparison with the healthy muscle.
is possible to demonstrate the irreversible cellular changes in the myocardium
20 minutes after the onset of experimental ischaemia by using the
electron-microscope. The electron-microscope is not usable in autopsy diagnosis
because of post mortem autolysis of tissues.
earliest, but not specific, changes of ischaemia are thinning, waving and
stretching of the muscle fibres observed with a light microscope, which
are caused by the traction of surrounding live musculature. After 12-24 hours,
coagulative necrosis of myocardial cells can be seen – the plasma is becoming
more eosinophilic and the nuclei are becoming pale (karyolysis) or shrunken and
darker (pycnosis); in the end, the myocardial cells are changed into shrunken,
eosinophilic anuclear formations without cross-striation. After 24 hours, an
infiltrate of neutrophils occurs in the interstitium; the infiltrate is the
most extensive after 2–3 days.
3–7 days there is disintegration of necrotic cells and macrophages can be seen
in the infiltrate. Substitution of the necrotic myocardium by granular tissue
(capillaries with endothelium, fibroblasts and sparse lymphocytes) begins on
the 5th–7th day. The majority of the infarcted focus is substituted by about
the 10th day. The granular tissue turns completely into stable collagenous cicatrix
over the next 6 weeks. (5)
most cases of interest to the forensic pathologist, the death is sudden and the
morphological changes of infarction do not have time to develop. In these
occasions the positive diagnosis of AMI is difficult. In such cases,
complementary diagnostic techniques, such as the determination of biochemical
markers (myoglobin, troponin I and CK-MB) in cadaver fluids, were
suggested. (7, 3, 1, 6) We decided to test the diagnostic value of postmortem
cTnI, myoglobin and creatine kinase determinations in serum and pericardial
Materials and methods
studied 71 cadavers, which were divided into 2 groups. The first group (38
cases) was formed by people who died with acute myocardial infarction (the
myocardial lesion could be easily detected by macroscopic examination or by
formazan test and the constriction or obturation of the coronary arteries was
detected and other causes of death were excluded) – AMI deaths. The second
group (non-AMI deaths) was formed by 4 cases of cardiac failure, 6 cases of
intracerebral haemorrhage, 5 cases of pulmonary embolism, 7 cases of asphyxia
(4 hangings, 1 traumatic asphyxia, 2 drownings), 3 cases of brain contusion, 2
cases of carbon monoxide poisoning, 1 case of cyanide poisoning, 1 case of alcohol
poisoning, 1 case of epilepsy, 1 case of bronchopneumonia, 1 case of
hyperglycaemic coma and 1 case of exsanguination. The blood was collected from
the femoral vein.
The average age of all the deceased was 58.4
years, the average age of the AMI group was 60.3 years.
Women formed 26.8 % of all cases (but only
one was in the AMI group).
Cardiopulmonary resuscitation was pursued in
44.7% in the AMI group and in 12% in the non-AMI group. Other than
post-resuscitation traumatic changes were found in 2.6% of the AMI group (i.e.
haematomas, fracture of femur) and in 27% of the non-AMI group (i.e. brain
contusion, chest contusion, many excoriations, extensive haematomas).
The heart weighed more than 350 grams in
94.7% of the group of AMI deaths (average weight 452 grams), and in 82% of the
non-AMI group (average weight 387 grams).
Pulmonary oedema was found in 97.4 % of the
AMI group and in 60.6 % in the group of non-AMI deaths.
Alcohol was positive in 21% of the AMI group
and in 30% of the non-AMI group.
The formazan macroreaction test was positive
in 3 cases of non-AMI deaths (alcohol intoxication, drowning, pulmonary
There were macroscopically visible acute
ischaemic changes in the heart in 68.4% and total atherothrombotic closure in
13% of the deceased in the AMI deaths group.
Chronic ischaemic changes (i.e. myofibrosis)
were macroscopically visible in 63% of cases in the AMI deaths group and in
almost 58% of cases in the non-AMI deaths group.
The average values of biomarkers in blood
and in pericardial fluid in the AMI deaths and non- AMI deaths groups are in
Table 2 and Table 3.
Creatine kinase and myoglobin were increased
in blood and in pericardial fluid in all AMI and non-AMI deaths; there was no
statistical difference in their concentrations between these groups.
Troponin I was increased in pericardial
fluid in all cases of both groups, there was no statistical difference in concentrations
in these groups.
Troponin I was increased in blood in
87% of AMI deaths and in 91% of non-AMI deaths; this difference is not
statistically significant; there is no statistical difference in concentration
in these groups.
studies discussing the efficacy of the postmortem determination of biochemical
markers in IHD and the possibility of using them in the diagnosis of acute
myocardial infarction have been undertaken recently (7, 3, 1). Statistically
significant differences in pericardial fluid for cTnI, CK-MB and myoglobin
between myocardial infarction and other deaths were obtained (7), but in serum
only cTnI showed statistically significant differences. The authors of this
study recommended the use of CK-MB and cTnI in pericardial fluid in postmortem
diagnosis as a factor with a high negative predictive value for AMI.
the study (8) it can be concluded that blood is not a suitable medium for
determination of biochemical markers of cTnI and atrial natriuretic peptide (pro-ANP)
for postmortem diagnosis of myocardial damage and for determining the diagnosis
of sudden cardiac death in a manner similar to the diagnosis of myocardial
damage in living patients.
in our study we did not find statistically significant differences in
pericardial fluid and in serum for cTnI, CK and myoglobin between the group of
AMI deaths and the group of non-AMI deaths and we cannot confirm the diagnostic
efficacy of these biochemical markers in postmortem diagnosis of acute
myocardial infarction. We cannot attribute the increased values of all
biochemical markers in both groups to heart damage as a consequence of
resuscitation. The proportion of resuscitation was higher in the AMI group
(44%) in comparison to the non-AMI group.
the evaluation of postmortem diagnosis of early myocardial infarction we should
still rely on up to the present time well known methods- macroscopic
examination, formazan test or histological evidence of acute infarction.
MUDr. František Vorel, CSc. Oddělení soudního lékařství Nemocnice České Budějovice, a.s. B. Němcové 585/54 370 01 České Budějovice
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