The 12 Leads of Christmas: Lead I

This article is the first in our latest series, The 12 Leads of Christmas, where each day we examine a new finding particular to an individual electrocardiographic lead. The Lead I Sign This patient has COPD.   So does this patient.   How do I know that? Well, I met the patients and they told me, but there’s also a very specific (but not very common) sign of COPD present on both tracings: the “lead I sign.” This manifests as nearly isoelectric complexes in lead I with barely any visible P, QRS, or T-waves. Often termed “Schamroth’s sign” or “Schamroth’s pattern,” it should not be confused with Schamroth’s window test for identifying clubbing of the fingers. Schamroth’s window test.1   Also known as the “isoelectric lead I sign,” as far as my research can tell it was first identified and termed the “lead I sign” in 1965 by N.O. Fowler et al. in a series of 15 patients with severe emphysema and cor pulmonale.² The term was popularized, however, by Dr. Leo Schamroth, cardiologist and Chief of Medicine at Baragwanath Hospital in South Africa , and likely bears his name thanks to the efforts of Dr. Bill Nelson and his use of the eponym. Though there is mention of strict voltage criteria in the Fowler paper (isoelectric P-wave, total QRS < 1.5 mm, T-wave <0.5 mm), Dr. Schamroth himself never used those numbers and simply described his sign as: “absent or very low...
Source: EMS 12-Lead - Category: Cardiology Authors: Tags: 12-Leads of Christmas Original Articles Vince DiGiulio Source Type: research