[Studies on the reliability of the polarcardiographic records (author's transl)].

Reliability of the polarcardiogram obtained by the newly constructed polarcardiograph, in which the vector sum circuit applying absolute value operations were used for the computation of the magnitude curve, were examined in fifty normal subjects. There was no statistically significant difference between the means of the measured values of the polarcardiogram and of the corresponding polar components calculated from the three scalar ECG concerning all twenty items, namely spatial magnitude, magnitudes in each plane, each longitude and latitude at the time of the spatial maximum QRS and T vectors, except alpha-longitude. Highly significant positive correlations were observed between these two sets of values in all twenty items. Configurations of the pattern obtained by plotting the instantaneous polar components, which were calculated from the three scalar ECG, on the linear time scale were very similar with those of the polarcardiographic records. These findings showed that the records obtained by the newly constructed polarcardiograph were reliable.