Dipole analysis of data base for body surface potential maps of normal population

: The dipolarity of the body surface potential distribution and locus of the main dipole were estimated by means of the least square method in data base for body surface potential maps of normal population. The main dipole moved smoothly within the actual cardiac region and was inscribed in a clockwise direction during the QRS. The nondipolar content (residue) showed time-dependent fluctuation the QRS. The main dipole during the T wave moved near the center of the heart. The nondipolar content during the ST-T period was less fluctuation than that during the QRS. These results indicated that a large percentage of the body surface potential maps of normal population could be represented by a single moving dipole.