[Acute risk factors for the onset of acute coronary syndromes].

Acute coronary syndrome (ACS) is an important entity of the cardiovascular morbidity and mortality. Everyday circumstances which significantly increase the risk of the onset of ACS during the period of several hours have been termed acute risk factors. This term includes morning hours and various possible external triggers such as heavy physical exertion, emotional stress, sexual activity, meteorological stress, and large meals. Possible external triggers precede approximately a half of the onsets of ACS, more frequently in men. Conversely, emotional stress plays a more important role in the triggering of ACS in women. Circadian rhythm represents an independent natural pattern of endogenous functions which is responsible for the morning excess in the incidence of ACS. A beneficial effect of regular physical activity and use of beta-blocker, calcium antagonists, nitrates and aspirin in the prevention of triggering ACS by acute risk factors has been described. Identification of further acute risk factors and better understanding of internal triggering mechanisms may improve the prevention of ACS and other cardiovascular incidents.