Diagnosis of myocardial infarction at autopsy: AECVP reappraisal in the light of the current clinical classification

Figures

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  Fig. 1. Coronary artery segments with different degrees of atherosclerotic stenosis. The diagrams demonstrate a 50% area stenosis, 75% stenosis and 90% stenosis; diameter x will usually be less than 2 mm in the left main stem and less than 1 mm in other major coronary arteries

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  Fig. 2. Patterns of topographic distribution of MI in the heart: regional transmural infarction; regional subendocardial infarction; circumferential subendocardial infarction; diffuse multifocal infarction

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  Fig. 3. Visualization of coronary collaterals in post-mortem angiograms. Contrast filling of right coronary artery (RCA) shows retrograde filling through collaterals of a large marginal branch of occluded left coronary artery (a). Contrast filling of RCA of another heart shows extensive ‘bridging collaterals’ surrounding a chronic total occlusion of the artery (b)

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  Fig. 4. Histological features of MI at different stages, without reperfusion; myofiber waviness (a); interstitial oedema (b); hypereosinophilia and coagulative necrosis of cardiomyocytes (c); heavy granulocyte infiltration with karyorrhexis (d); macrophages and lymphocyte infiltration with early removal of necrotic debris (e); granulation tissue with formation of microvessels (f); fibroblast proliferation and early collagen deposition (g); dense fibrous scar replacing myocyte loss (h). All sections are stained with haematoxylin and eosin

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  Fig. 5. Nitro blue tetrazolium (NBT)-stained myocardium; myocardial slice (middle) with circumferential subendocardial infarction indicated by loss of staining (pale area); purple-stained tissue represents vital myocardium, heart and apical slice are not NBT treated

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  Fig. 6. Immunostaining of early myocardial infarction. Positive staining for fibronectin (a) and C5b-9 (b) in irreversibly injured cardiomyocytes. Scale bars = 50 μm. Courtesy from Aljakna et al., Int J Legal Med, 2018; acute myocardial infarction in papillary muscle immunostained with C4d antibody (brown). Low power view, bar = 0.25 mm, highlights exact delineation of necrotic areas (geographic zones, and multifocal cells) (c); Higher magnification, bar = 50 μm, shows abrupt border between vital tissue and necrotic area (d)

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  Fig. 7. Histological features of MI with reperfusion; Detail of myocardium with contraction band necrosis (a); microvascular damage and extravasation of erythrocytes (b); macroscopic image of the heart with left ventricular widespread circumferential subendocardial haemorrhage(c); embolus of guide wire coating (blue material) surrounded by giant cells and some lymphocytic infiltration in myocardial microvessel of a previously PCI treated (stented) coronary artery (d); Histologic sections stained with haematoxylin and eosin