TRIGGERS OF ACUTE MYOCARDIAL-INFARCTION REGARDING ITS SITE

We have studied the incidence of possible triggers of the myocardial i nfarction regarding its site in 750 patients with anterior and 731 pat ients with inferior infarction. Infarctions occurred most frequently w ithout recalling any triggering activity, especially in patients with anterior infarction (67 vs. 44%). Physical effort as the possible prec ipitator was also more frequent in anterior infarctions (22 vs. 16%). However, the onset of inferior infarction was more frequent during met eorological stress (9 vs. 2%), emotional stress (10 vs. 3%), after ove reating (13 vs. 3%) and nicotine abuse (6 vs. 1.5%). These triggers we re independent and highly significant (P<0.02 in each case) discrimina tors of the site of myocardial infarction. Bimodal circadian rhythm, w ith primary peak between 6 and 9 h a.m. and the secondary peak between 3 and 6 p.m. was observed in patients which did not recall any trigge ring activity, and this was more pronounced in patients with inferior infarction. These results support the hypothesis that the influence of the vegetative tone is most pronounced in the onset of myocardial inf arction of inferior wall. (C) 1997 Elsevier Science Ireland Ltd.