A Study on Normal Polarcardiogram by Digital Computer Analysis

Abstract

Methods using polar coordinates to display heart vector and their clinical usefulness have been reported by many investigators. In the present study, normal findings of polarcardograms, timerelated curves of sequential changes of spatial magnitudes and orientations of heart vector, were studied. Materials and Methods: Thirty healthy men ranging in age from 19 to 45 (average 25.2 years old) were included in this study. In all, simultaneous high-speed recording of the three scalar ECGs of Frank system were obtained by Mingograph Type 81 recorder (1, 000 mm per second and 1 mV=1 cm). These scalar ECGs were digitalized at each 0.002 second interval from the biginning to the end of QRS for the analysis of QRS wave and at each 0.91 second interval from the end of QRS to the end of T for the analysis of ST segment and T wave. About seventy digitalized measurements obtained by this method were used as input signals to the digital computer (Tosbac Type 3400) in order to calculate the instantaneous magnitudes, longitudes and latitudes of QRS wave, ST segment and T wave. The calculated values were printed out in numerical from and the sequential changes were plotted out in curves by automatic plotter. Three polar axes, namely the postero-anterior, infero-superior and right-left axes, were employed in this study. Time-related curves of the sequential changes of the electomotive forces of the heart expressed in polar coordinates were named as below following Dower, namely the spatial magnitude ECG (SM); the frontal, transverse and sagittal magnitude ECG (fm, tm and sm); the alpha-, beta- and gamma-longitude ECG (alpha-, beta- and gamma-long); postero-anterior, infero-superior and right-left latitude ECG (P-A, I-S and R-L lat).