CIRCADIAN VARIATION IN THE ONSET OF ACUTE MYOCARDIAL-INFARCTION - LACK OF AN EFFECT DUE TO AGE AND SEX

The circadian patterns in the onset of symptoms of acute myocardial in farction were assessed in a prospective study involving 450 patients. Analysis of the data in the 424 patients in whom the time of onset was known did not show any statistically significant circadian rhythms, e ither for the group as a whole or for subgroups divided according to s ex, age group (< 60, 60 - 69, 70 - 79 and greater-than-or-equal-to 80 years old), or the presence or absence of diabetes mellitus. The frequ ency of onset of symptoms was highest in the morning (06.01 - 12.00 h) for the group as a whole (29.2%). Patients aged < 70 and greater-than -or-equal-to 80 years old showed a peak in the morning, whereas patien ts aged 70 - 79 years old showed a peak in the afternoon (12.01 - 18.0 0 h).