RECONSTRUCTION OF THE STANDARD 12-LEAD ECG FROM RECORDINGS USING NONSTANDARD ACTIVITY-COMPATIBLE PROXIMAL LIMB LEAD POSITIONS

Proximal or torso placement of limb leads in the 12-lead electrocardio gram (ECG) has been shown to influence the appearance of QRS waveforms considerably. A method was developed for computer-based reconstructio n of standard-like waveforms from nonstandard torso-recorded waveforms . Reconstruction coefficients required by the method were determined u sing ECG data obtained from 30 patients. The coefficients were then ap plied on an independent test set of 100 patients. In 21 of these patie nts, a second standard EGG was obtained the next day to determine the day-to-day variation in QRS waveforms. R wave amplitudes in leads I an d II, and electrical axes in the frontal plane were measured in the st andard ECG, the nonstandard ECG, and the reconstructed ECG. It is show n that the reconstruction method yields ECGs that differ less from sta ndard than do two standards ECGs recorded on consecutive days. The per formance of the reconstruction method was not influenced by age, sex, height, or weight.