Triggers of acute coronary syndromes☆
Section snippets
General theory for triggering of acute coronary syndromes
It is proposed that the onset of an acute coronary syndrome can result from an interaction between a vulnerable plaque, a trigger, and acute risk factors. (Fig 1) As noted, the coronary plaque suspected to be most vulnerable to rupture is lipid rich and has a thin fibrous cap that is weakest at its junction with the intima,14 probably caused by increased inflammatory cellular activity with elaboration of metalloproteinases.15
Circadian variation of MI
The onset of MI has a distinct daily pattern with a peak incidence in the hours after awakening and arising. Serum creatine kinase (CK) measurements obtained from 703 subjects in the Multicenter Investigation of Limitation of Infarct Size study27 were used to demonstrate a marked circadian variation in the incidence of MI, with a threefold increase at 9 AM compared with 11 PM (Fig 2).
Cardiovascular triggers
The circadian, circaseptan, and circannual variations in the incidence of onset of MI suggest that the onset of acute cardiac events is not random but rather can be triggered by endogenous rhythms in combination with external activities and exposures. The Myocardial Infarction Onset Study (MIOS) investigators have identified several activities/exposures that serve as triggers of MI onset including heavy physical exertion, anger, mental stress, sexual activity, cocaine use, marijuana use, and
Physical activity
Physical activity has a favorable effect on the lipid profile by lowering total serum cholesterol and triglycerides and raising high-density lipoprotein cholesterol. In addition, physical activity is associated with reduced blood pressure, improved glucose tolerance, increased insulin sensitivity, and reduced blood coagulability.72 The higher rate of infarction in the morning hours has raised concerns about the desirability of physical activity during this time period. Murray and colleagues73
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2020, International Journal of Hygiene and Environmental HealthCoronary artery disease, sudden death and implications for forensic pathology practice
2017, Diagnostic HistopathologyRisk and Protective Factors for Sudden Cardiac Death During Leisure Activities in the Mountains: An Update
2017, Heart Lung and CirculationThe myth of the "vulnerable plaque": Transitioning from a focus on individual lesions to atherosclerotic disease burden for coronary artery disease risk assessment
2015, Journal of the American College of CardiologyCitation Excerpt :Specifically, we need to understand and potentially to predict the response of the coagulation system to stimuli occurring with atherosclerotic plaque alterations. Variability in the coagulation system’s performance depends on numerous hormonal, dietary, and environmental influences, hampering our ability to predict its function at a given time, for example, when plaque ruptures (90–92). Thus, we must strive for comprehensive risk assessment that integrates specific information on the atherosclerotic plaque burden and systemic factors that increase the risk for disease activity and vascular thrombosis and is tailored to specific patient populations and individual patients.
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Address reprint requests to James E. Muller, MD, Cardiology Division, Massachusetts General Hospital, Boston, Massachusetts, 02114.