Korean Circ J.  1984 Dec;14(2):253-257. 10.4070/kcj.1984.14.2.253.

Difference in QRS Onset in an Electrocardiogram by Lead Selection

• Lee HW
• Lee CK
• Jun JE
• Park WH

• KMID: 2093188
• DOI: http://doi.org/10.4070/kcj.1984.14.2.253

Abstract

To determine the difference in QRS onset in an electrocardiogram(onset of ventricular depolarization) by lead selection, simultaneous recording of three standard leads and that of three unipolar limb leads were compared between 64 electrocardiographically normal subjects(group I) and 36 abnormal cases(group II). The frequency of synchronous QRs onset in all three leads was 1% for standard leads and 3% for unipolar limb leads. Among standard leads, the earliest QRS onset was most frequent in lead III followed by lead II and I in decreasing order for both groups I and II. The time intervals between the earliest and the latest QRS onset varied from 1.0 to 26.5 msec with a mean of 7.8 msec. Among the unipolar limb leads, the lead which showed the earliest QRS onset most frequently was different between groups I and II, although the time interval between the earliest and the latest QRs onset was essentially similar to that in standard leads. This suggests that it is feasible to include standard lead III, among six leads included in standard and unipolar limb leads, in various cardiographic studies for the identification of onset of ventricular depolarization, and that the indiscriminate routine use of lead II appears to be a poor choice.

MeSH Terms

Electrocardiography*
Extremities