Quantitative Evaluation of the St-T Pattern in the Exercise Electrocardiogram

A new method for the quantitative analysis of the exercise electrocardiogram was developed for the diagnosis of coronary heart disease. In this method, a second order function, f(t)=at2+bt +c, which represents the configuration of the initial portion of the ST-T segment was obtained by the function fitting method and its coefficients a (a parameter which represents the ST-T pattern) and c (a parameter which reflects the ST junction's depression) were used for the evaluation of the exercise electrocardiogram. Serial changes in the ST-T pattern throughout exercise tests were also investigated using this method in two distinct groups; a group of 35 healthy adults (group H) and a group of 28 patients with effort angina pectris (group EA). Although the smaller coefficients a and c which were obtained during an after exercise tests in group EA may reflect the ischemic changes, substantially large overlaps in each of these parameters was observed between group H and group EA. However, the discrimination between these two groups was improved if the combination of coefficients a and c were applied. These results strongly suggest that the configuration of the ST-T pattern is indispensable for the evaluation of the exercise electrocardiogram and that the new quantitative method used in this study is useful in the objective analysis of the fine changes in the ST-T pattern.