On the use of chest leads in clinical electrocardiography

Abstract

The literature on chest leads in clinical electrocardiography is reviewed. This review is accompanied by comments on articles and case reports dealing with the subject. The early literature appears to be colored by an unwarranted enthusiasm on the subject, leading on the one hand to an overemphasis of the value of chest leads, and on the other to a tendency to underrate the significance of abnormalities in the standard leads. The coventional chest leads, Leads IV, V, and VI have been examined, and their significant features are discussed. It is suggested that a chest lead for routine electrocardiography embody the following features: (a) that its tracing record maximal deflections and that it include well-defined auricular as well as ventricular complexes; (b) that its tracing be symmetrical with the standard leads; and (c) that the chest lead require but a single chest electrode. The right arm chest lead has been found to fulfill these requirements. Objections are offered to the numerical designation of chest leads. It is suggested that instead chest leads be designated by well-known anatomical landmarks, indicating the location of the principal or chest electrode. Right pectoral (Rp), left pectoral (Lp), and apical (Ap) leads are suggested as routine chest leads in clinical electrocardiography. In these the right arm attachment used in the standard leads serves as the fixed secondary electrode, and the principal or chest electrode is attached to the left arm cable. It is concluded that while chest leads have found a permanent place in clinical electrocardiography, standard leads are still to be regarded as the more dependable, and a parallel study of standard lead tracings, particularly with reference to minor deviations, should be persued with at least as much attention as the study of chest leads.