Multivariate analysis of body surface potential maps in left ventricular hypertrophy

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