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Updated: Aug 12, 2026
A Thrombotic Stroke Model Based On Transient Cerebral Hypoxia-ischemia
Published on: August 18, 2015
Triggering and hourly variation of onset of arterial thrombosis
1Institute for Prevention of Cardiovascular Disease, New England Deaconess Hospital, Boston, MA 02215.
Insights
Daily activities and stress can trigger heart attacks and sudden cardiac death, especially in the morning. Understanding these circadian patterns is key to preventing cardiovascular events.
Area of Science:
- Cardiology
- Circadian Biology
- Vascular Medicine
Background:
- Daily activities and stress are increasingly recognized as triggers for myocardial infarction and sudden cardiac death.
- Circadian variations in cardiovascular events suggest underlying physiological mechanisms influenced by daily rhythms.
Purpose of the Study:
- To investigate the role of daily activities and stress in triggering acute coronary events.
- To elucidate the mechanisms underlying the circadian onset of myocardial infarction, sudden cardiac death, and stroke.
- To propose a hypothesis for the sequence of events leading to occlusive coronary thrombosis.
Main Methods:
- Analysis of circadian variations in the onset of myocardial infarction, sudden cardiac death, and stroke.
- Examination of the relationship between transient myocardial ischemia, mental/physical triggers, and morning hours.
- Review of evidence on atherosclerotic plaque rupture, hypercoagulable states, and morning-enhanced physiological processes.
- Consideration of the effects of aspirin and beta-blockers on disease onset.
Main Results:
- Frequencies of myocardial infarction, sudden cardiac death, and stroke exhibit significant morning circadian variations.
- Transient myocardial ischemia episodes increase in the morning, often preceded by stress.
- Atherosclerotic plaque rupture is a common precursor to coronary thrombosis.
- Physiological factors like hypercoagulability and vasoconstriction are heightened in the morning.
- Pharmacologic agents like aspirin and beta-blockers can prevent disease onset.
Conclusions:
- Occlusive coronary thrombosis results from vulnerable plaque rupture, triggered by stress, and exacerbated by morning hypercoagulability and vasoconstriction.
- Recognizing circadian vulnerability necessitates pharmacologic protection during high-risk periods.
- Understanding these triggers and mechanisms can lead to improved prevention strategies for acute cardiovascular events.
Abstract:
Information obtained during the past decade suggests that the onset of myocardial infarction and sudden cardiac death is frequently triggered by daily activities. The importance of physical or mental stress in triggering coronary thrombosis is supported by finding that (1) the frequencies of the onset of myocardial infarction, sudden cardiac death, and stroke show marked circadian variations, with similar increases in the period from 6 AM to noon; (2) the frequency of transient myocardial ischemia shows a similar increase in the morning, and episodes are often preceded by mental or physical triggers; (3) a ruptured atherosclerotic plaque, often nonobstructive by itself, lies at the base of most coronary thrombi; (4) a number of physiologic processes that could lead to plaque rupture, a hypercoagulable state, or coronary vasoconstriction, are accentuated in the morning; and (5) aspirin and beta-adrenergic blocking agents that affect certain of these processes have been shown to prevent disease onset. The hypothesis presented is that occlusive coronary thrombosis occurs when (1) an atherosclerotic plaque becomes vulnerable to rupture; (2) mental or physical stress causes the plaque to rupture; and (3) increases in coagulability or vasoconstriction, triggered by daily activities, contribute to complete occlusion of the coronary artery lumen. Recognition of the circadian variation--and the possibility of frequent triggering--of the onset of acute disease suggests the need for pharmacologic protection of patients during the vulnerable periods and provides clues to the mechanism of disease onset, the investigation of which may lead to improved methods of prevention.
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