Acute myocardial infarction: recent physiopathological data. 1: acute coronary occlusion
Monassier, J.P.; Hanssen, M.; Ameur, C.; Weisse, D.; Zimmermann, A.; Laval, G.
Archives des Maladies du Coeur et des Vaisseaux 85(5): 663-670
1992
ISSN/ISBN: 0003-9683 PMID: 1530407 Document Number: 390393
Acute myocardial infarction is the result of sudden coronary occlusion in the absence of a collateral circulation. There main factors are required for this to occur: an acute parietal lesion on a stenosis of variable, sometimes minor, importance; local coronary vasoconstriction and a platelet and fibrin thrombus. Parietal fissuration is the commonest "trigger" of coronary spasm and the thrombotic cascade. All factors of coronary occlusion are potentially reversible--vasodilation--platelet anti-aggregation--physiological fibrinolysis--remodeling and cicatrisation of the plaque, thereby explaining cases of spontaneous regression of occlusion (10% at 1 hour; 20% at 6 hours; 30% at 24 hours; 50 to 70% at 1 year). The pathogenesis of myocardial infarction with angiographically normal coronary arteries may be reviewed and attributed to acute parietal fissuration at a non-significant or angiographically undetectable plaque resulting in occlusive thrombosis. In this case, the role of other pathogenic factors is also discussed (diabetes, oral contraception, haemostatic abnormalities, platelet disorders...).