Effect of age on systolic intervals (STI)

Weissler's corrected STI was to be used in the assessment of cardiac performance taking into account only the heart rate and sex. But there are many other determinants of STI, among them an important one is the age. In the present paper, in 422 normal adults (280 men and 142 women) divided according the age into three groups (20-29, 30-39, 40-60 years), we found significant differences concerning STIc with age, especially over 40 years old. On the other hand, in a previous paper we have found in trained athletes similar modifications of STIc as those noticed in cardiac failure. That is why we, like other authors, do not consider Weissler's STIc as valid in the assessment of cardiac performance.