Proximal placement of limb electrodes: a potential solution for acquiring standard electrocardiogram waveforms from monitoring electrode positions.

There is currently a challenge to produce an electrocardiogram (ECG) recording of waveforms that are "standard" and also achieve the "noise immunity" required for continuous monitoring. The potential solutions that have been considered are to label each torso-recorded ECG as "nonstandard, torso-recorded," designate torso placement as "standard," or to reconstruct the "equivalent distally recorded ECG." The purpose of the present study was to validate an alternative "Lund system" of proximal limb electrode sites as a clinically feasible solution to this challenge. Data were collected from 75 patients referred for exercise testing at the Lund University Hospital. The Lund system produced Q wave dimensions and frontal plane QRS axis measurements that were in much better agreement with the standard ECG than those variables recorded with the Mason-Likar torso limb electrode method. Indeed, the Lund system replicated distal waveforms at a clinically acceptable level. Studies of larger patient cohorts including patients with various cardiac pathologies and studies of the noise immunity attained should be performed, and the acceptability by health care professionals should be determined.