Investigation of cardio-vascular reflex in atomic bomb survivors, (2)

Electrographic R-R interval variation was examined in a total of 915 A-bomb survivors exposed at ≤2,000 m from the hypocenter (the ≤ 2,000 m group) and a total of 1,162 A-bomb survivors exposed at >3,000 m or entered the city after the A-bombing (the >3,000 m group). Coefficient of variation (CV) for R-R interval variation on ECG tended to be decreased with advancing age in the >3,000 m group, irrespective of sex. Especially for men in this group, CV values were significantly lower for the age group of 45 to 54 years than the groups of 65 to 74 years and 75 to 84 years. Similar tendency was observed for CV values at deep breath. Decreased CV values tended to be associated with a decrease in glucose tolerance in both men and women of the >3,000 m group. In comparing the aforementioned CV values with those in the ≤2,000 m group, there was no significant difference between the groups. R-R interval variation on ECG was found independent of exposure condition, although it was influenced by sex, age, and glucose tolerance. (N.K.)