Approximately 90% of MIs result from an acute thrombus that obstructs an atherosclerotic coronary artery. Plaque rupture and erosion are considered to be the major triggers for coronary thrombosis. Following plaque erosion or rupture, platelet activation and aggregation, coagulation pathway activation, and endothelial vasoconstriction occur, leading to coronary thrombosis and occlusion.
Within the coronary vasculature, flow dynamics and endothelial shear stress are implicated in the pathogenesis of vulnerable plaque formation. A large body of evidence indicates that in numerous cases, culprit lesions are stenoses of less than 70% and are located proximally within the coronary tree. Coronary atherosclerosis is especially prominent near branching points of vessels. Culprit lesions that are particularly prone to rupture are atheromas containing abundant macrophages, a large lipid-rich core surrounded by a thinned fibrous cap.
Nonmodifiable risk factors for atherosclerosis include the following:
Age (> 45 for a male; > 55 for a female)
Male sex
Family history of premature coronary heart disease
Postmenopausal status
For more on the risk factors for MI, read here.
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Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Yasmine S. Ali. Fast Five Quiz: Are You Prepared to Confront a Myocardial Infarction? - Medscape - May 26, 2016.
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