II. Diagnosis of Left Ventricular Hypertrophy and Myocardial Infarction from "Total" Surface Waveform Information

Abstract

Eight surface leads were found to account for the "total" waveform information in 282 patients (145 normal subjects, 59 patients with LVH, and 78 with myocardial infarction). In each patient the Frank leads were also reconstructed. After time normalization of the eight leads and the XYZ leads and division of the QRS complex into eight equal parts, the resulting variables (64 in the eight lead system and 24 in the Frank lead system) were submitted to multivariate statistical procedures. In a first step, the variables which proved best for the differentiation between normal records and those from patients with LVH or myocardial infarction were selected through stepwise discriminant analysis. A discriminant function was then computed and applied to both pathological groups. The results clearly point up the superiority of the eight lead system. With the level of specificity kept constant at 95%, 91% of the patients with LVH and 95% of the patients with myocardial infarction were correctly classified. With the Frank leads 83% and 85%, respectively, were recognized. The reproducibility of the results also proved to be better with the eight lead system.

Activation patterns in atrial fibrillation: contributions of body surface potential mapping.

“…Similar results have been also observed in [72], where in patients suffering from BBB more leads were needed to contain the same information content than in patients with other pathologies.…”

The Missing Waveform Information in the Orthogonal Electrocardiogram (Frank Leads)

“…33' 34 356, 37 The diagnostic results were compared with those obtained with the Frank leads. 38 This paper describes the performance of the 9-lead sys-tem in angina pectoris using the same statistical procedures applied to the QRS complex at rest.…”