Characteristics of the electrocardio-gram under physical and emotional stress in man.

The changes in the length of interval R-R and in heart rate are widely used for estimation of man's physical state. How-ever, this ECG index has several drawbacks including a relatively low sensitivity and non-specificity, unindirection of changes under different states: attention and fatigue, physical and emotional stress, etc. Moreover, one and the same factor, e.g. emotional stress, can lead both to a decrease and an increase in the heart rate. Hence, it is necessary to find other more adquate ECG parameters, which would enhance the reliability and accuracy of assessment of man's state. The analysis of data found in literature and the results of our preliminary experiments have shown that the amplitude of the t-peak and duration of the R-T interval of ECG can be used as such parameters.