A reference data base for multilead electrocardiographic computer measurement programs

Abstract

In an effort to standardize and evaluate the performance of electrocardiographic computer measurement programs, a 15 lead reference library has been developed based on simultaneously recorded standard 12 lead and orthogonal XYZ lead data. A set of 250 electrocardiograms (ECGs) with selected abnormalities was analyzed by a group of five referee cardiologists and 11 different 12 lead and 6 XYZ computer programs. Attention was focused on the exact determination of the onsets and offsets of P, QRS and T waves. The referees performed their task on highly amplified, selected complexes from the library in a two round process. Median results of the referees coincided best with the median derived from all programs. An analysis of stability proved that the combined program median was a robust reference. However, some individual program results were widely divergent. Paired t tests demonstrated earlier onset for P and QRS (p less than 0.001), as well as later offset for P and T waves in the median 12 lead than in the XYZ results. Significant differences also existed among results obtained by programs analyzing all standard ECG leads at one time, the so-called multilead programs, and those obtained by the conventional standard three lead analysis programs. As a consequence, the derived P, PR, QRS and QT interval measurements varied quite widely among the various programs. Significant differences were also observed among measurements of Q, R and S duration. Some programs showed Q waves that were on the average 6 ms (p less than 0.001) longer than those of others. This may significantly influence diagnostic performance.(ABSTRACT TRUNCATED AT 250 WORDS)

High free thyroxine levels are associated with QTc prolongation in males

“…The MEANS program has been evaluated extensively and has been validated (Willems et al 1987, van Bemmel et al 1990, de Bruyne et al 1997. In one of these validation studies, ECGs with selected abnormalities were analyzed by 5 cardiologists and 11 different computer programs of which MEANS performed as one of the best (Willems et al 1987) In another validation study in which QT intervals by manual measurement were compared with those generated by ECG machines, manual and automated measurements generated similar numerical results in three studies in healthy volunteers, which all included a positive control (Darpo et al 2006). MEANS determines common onsets and offsets for all 12 leads together on one representative averaged beat, with the use of template matching techniques (van Bemmel et al 1990).…”

Changes of the t‐wave amplitude and angle: An early marker of altered ventricular repolarization in hypertension

“…From each lead, the average complex was calculated by the MEANS (Modular ECG Analysis) system.22. 23 Individual averaged complexes were stored digitally. Standard criteria were used to diagnose ECG-documented LVH?4…”

Influence of Lead Selection and Population on Automated Measurement of QT Dispersion

“…Then, for each individual lead, a form of second derivative of the signal is used to locate the definitive T end. On the basis of a comparison with other programs published in 1987, 21 Given the availability of orthogonal XYZ leads, it is possible to derive the 12-lead ECG from these leads by the use of generally accepted equations. 22 For example, at any sampling instant, lead I can be derived as follows:…”