ORTHOGONAL ELECTROCARDIOGRAM DERIVED FROM THE LIMB AND CHEST ELECTRODES OF THE CONVENTIONAL 12-LEAD SYSTEM

Methods of computing orthogonal X, Y and Z voltages representing the equivalent heart dipole activity are described. These components were obtained as linear functions of voltages from the limb and chest electrodes of the conventional 12-lead system. The coefficients of these linear functions are given and a close relationship with the Frank lead system is demonstrated. Two methods were used to obtain transformation coefficients - the lead vector approach and the statistical least-squares fit. ECG data from 92 individuals (healthy and with cardiac disorders) were used to obtain adequate coefficient values.