Emotional stress and the electrocardiogram.

The joint function of electrocardiographic cycle duration and of the spatial magnitude of the repolarization maximum vector, recorded with the physically corrected orthogonal lead system McFee-Parungao was used for studies of the effect of mental arithmetics in man and of emotional stimulation in unrestrained macaques. This approach allowed to distinguish between heart rate changes with and without signs of direct sympathetic stimulation of the working myocardium, and to study the correlation between emotionally induced effects on the pacemaker and on ventricular myocardial fibers. The latter was found to be much more expressed in macaques than in man. Emotionally induced ECG changes may detect persons prone to hyperkinetic circulation.