Similarity of ST and T waveforms of 12-lead electrocardiogram acquired from different monitoring electrode positions

BackgroundIt is not always feasible to use standard electrode placement for limb leads when recording the 12-lead electrocardiogram (ECG). Other electrode placements have been accepted during monitoring. Nonstandard electrode positions, however, fail to produce waveforms identical to those recorded from the distal limb positions that are standard for diagnostic interpretation. The purpose of the present study was to validate the ST-T-segment for an alternative “Lund system” of proximal limb electrode sites.MethodsTwelve-lead ECGs (standard, Mason-Likar, and Lund lead placement) were collected from 167 patients.ResultsThere were systematic differences between measurements from standard vs Mason-Likar, but not vs the Lund system. The 95% confidence intervals of measurement agreement were similar or less when comparing measurements from the Lund system vs the first standard recording with measurements for the 2 standard recordings.ConclusionThe Lund system might constitute a uniform convention for “diagnostic” ECGs as well as for monitoring ECG applications with regard to ST-T waveforms.