Comparison of the Selvester QRS scoring system applied on standard versus high-resolution electrocardiographic recordings.

A comparison was performed between the points measured using the Selvester QRS scoring system in 60 electrocardiograms (ECGs) displayed in both a standard format as well as a 4-fold magnified (quad-plot) format. Fifty criteria (a maximum possibility of 31 points) were evaluated in each ECG. The data indicate that in 50% of the ECGs, an identical number of points were measured. However, there was a single point difference in 31%, 2 points in 15%, and more than 2 points in 4%. The differences were primarily because of points scored on the quad-plot but not on the standard ECG. Thus, a systematic underestimation of infarct size may occur when the Selvester QRS score is measured manually from a standard ECG.