An alternative limb lead system for electrocardiographs in emergency patients.

It is occasionally difficult to record the standard 12-lead electrocardiograph (ECG) in emergency patients. The aim of this study was to evaluate the influence on electrocardiographic wave form recordings of moving the location of electrodes from the standard limb lead position to the trunk. The participants were 10 normal subjects and 20 patients with heart disease. In the new lead system, the limb electrodes were placed on the anterior acromial region and the anterior superior iliac spine using adhesive electrodes. Conventional 12-lead ECGs were recorded by the standard and the new lead system simultaneously in the supine position. Wave form analysis was done by an automatic analysis program. Motion artifacts in the recordings were less in the new lead system. The R wave amplitude of the new lead system increased in leads II, III and aVF, and decreased in leads I and aVL. However, the amplitudes of each wave obtained by standard electrocardiography and the new lead system correlated well (y = 1.008x + 2.038, r = 0.99, n = 2,880). In 99.6% of all wave forms, the differences in amplitudes were within 5% of the values of standard recordings. The average of differences in the ST-segment was 2.6 +/- 11.4 microV. The frontal plane QRS axis obtained by the new lead system showed a vertical shift of 7.8 +/- 8.5 degrees (y = 0.94911x + 10.346, r = 0.98, n = 30). The recording errors produced by the new lead system were within the permissible range of variation. The new lead system is a reasonable alternative for recording ECGs if application of the standard lead is difficult in an emergency.