Résumé : Discriminant analysis was performed on ECG data simultaneously recorded using 120 leads for 250 normal subjects and 214 patients with left ventricular hypertrophy (LVH). Instantaneous voltages on time-normalized P, PR, QRS, and ST-T waveforms as well as the durations of these waveforms were used as features. A total of six features from five torso sites accounted for a specificity of 97% and a sensitivity of 94%. The single most potent discriminator was the duration of the P wave; voltages were measured in mid and late P, in mid QRS, and slightly before the peak of the T wave. The optimal sites for LVH diagnosis were in general outside the conventional ECG lead locations. In comparison, multivariate analysis on the standard 12 leads correctly classified 86% of pure LVH patients and 83% of complicated LVH cases at specificity rates of 94% and 93%, respectively.