Circadian variation and triggering of cardiovascular events

Abstract

Myocardial infarction and sudden cardiac death demonstrate a marked circadian variation with an increased risk during the morning after awakening and arising. The recognition of the morning increase of acute cardiovascular events has convinced many that they may be triggered by morning activities. It is of note, however, that cardiovascular events occur throughout the day -even if at lower frequency compared with the morning.There is a strong association between external triggers and the onset of myocardial infarction and sudden cardiac death beyond what is to be expected by chance alone. The magnitude of this association (relative risk two-to threefold) is comparable with the known long-term risk factors of cardiac disease. Trigger factors occur relatively frequently and may play a causative role in up to 20% of cases of acute coronary syndromes. Physical exertion, bursts of anger and sexual activity have been proved to have triggering potential. Other possible triggers include external and environmental events such as earthquakes, war threat and climatic factors.The pathophysiological links between external triggers and the onset of cardiovascular events are important in addressing the question of a causal relationship between triggers and disease onset and in perhaps improving preventive strategies.

A matter of life and death: population mortality and football results

“…7 Trigger factors have been estimated to play a causative part in 20% of cases of acute coronary syndrome. 18 Our results do not identify the trigger factors that may have provoked the additional deaths observed. Losing at home may lead to anger, frustration, or depression among supporters, which are known to increase the risk of acute coronary and cerebrovascular events including sudden death.…”

Firefighters and on-duty deaths from coronary heart disease: a case control study

“…Therefore, if on-duty CHD events had no relation to work, firefighter deaths should have a circadian pattern similar to the general population in whom cardiovascular events peak between 6 am and noon [45-48]. In stark contrast, we found most on-duty CHD fatalities occurred between noon and midnight.…”

Sex differences in potential daily triggers of the onset of acute myocardial infarction: a case-crossover analysis among an Iranian population

“…In fact, bad news can be defined as a sudden emotional stress. Between 20 and 40% of sudden cardiac deaths are precipitated by acute emotional stressors [6,11]. Studies in both animal models and humans confirmed a causal relationship between emotional stress and coronary atherosclerosis [12,13].…”