The Seasonal Susceptibility to Myocardial Infarction

A bstract The data on 539 patients (358 men and 181 women) with proved myocardial infarction, admitted to the hospital during a four‐year period, were reviewed and tabulated according to yearly and monthly intervals for both sexes. The admission rates were studied in relation to hypertension, hypercholesterolemia, diabetes, and mortality, and also in relation to the seasonal changes in temperature. The analysis showed that, for men, the curves representing admission and mortality rates were not characteristic. In contrast, for women, there were two distinct peaks of admission, in April and in December; a chi‐square value of 16.10 (df = 11) tended toward a significant difference. A similar tendency toward a significant difference was noted in the increased mortality for women in the spring months of March, April and May; chi‐square value, 4.76 (df = 3). Perhaps in women an additional factor of macrothrombus formation is somehow influenced by the season of the year.