Stress Tolerance in Subjects with Myocardial Infarction

In our course of surveys to study the relationship between stress and myocardial infarction (MI), we have investigated whether stress tolerance may play a significant role when MI develops. To elucidate the possible role of stress tolerance, we examined 96 patients with MI (68 men and 28 women, age 40-90 years) with a stress tolerance check list in which stress tolerance was quantified as total points for 20 self-evaluated items, each scored between 1 and 4 points. Their scores were compared with control values obtained from persons not suffering from MI, and further analyzed by dividing them into 3 groups according to their grade of stress tolerance; that is, low (39 or less in score), moderate (40-49) and high (50-80). The mean stress tolerance score (± SD) was significantly lower in the 96 MI patients (49.5 ± 8.90 points) than in the controls (60.8 ± 7.3 points). The stress tolerance grade was low in 13 of the 96 (13.5%), moderate in 34 (35.5%) and high in 49 (51.0%). In MI patients, lowly or moderately stress-tolerant persons were significantly higher in percentage (49.0%) than in the controls (6.3%). These results clearly indicate that low stress tolerance is a risk factor in the development of MI.