Alternative Lead Systems

The Lewis or S5 Lead

Christopher Watford  has described the physiology and advantages of the Lewis lead extensively in his blog post, Highlighting Atrial Activity on an ECG: The S5 Lead,  as well as via audio on the EMCrit Podcast with Scott Wiengart. References as follows:

  1. Bakker, A., et al. (2009). The lewis lead: Making recognition of P waves easy during wide QRS tachycardia. Circulation, (2009), 119; e592-e593. [Free Full Text] doi: 10.1161/CIRCULATIONAHA.109.852053
  2. Lewis T.  (1931). Auricular fibrillation. Clinical Electrocardiography. 5th ed. London, UK: Shaw and Sons; 1931: 87–100.

High and Low Precordial Sequences

“High” and “Low” precordial leads have been utilized to visualize underrepresented regions of myocardium (such as the high lateral wall), as well as to better appreciate the typical 12-lead perspective when the heart is shifted up or down in the chest (as in emphesema). The Cardiophile blog describes this in greater detail.

Brugada Leads

ECG from a Brugada syndrome patient showing most severe ST–T abnormalities in leads overlying right ventricular outflow tract (shaded area): coved-type ST segment in second and third intercostal space (V2IC2 and V2IC3). Intermediate ST–T abnormalities (saddleback-type) arerecorded in fourth intercostal space (V2IC4). [Graphic and text – Meregalli, et al., 2005]

[Unknown image source.]

The three types of Brugada syndrome as seen on ECG. Image retrieved from

[Image retrieved from Life In The Fast Lane:]

  1. Meregalli, et al. (2005). Pathophysiological mechanisms of Brugada syndrome: Depolarization disorder, repolarization disorder, or more? Cardiovascular Research, 67, 2005, 367-378. [Free Full Text]

Body Surface Mapping

Heartscape Technologies has a case library describing some of the benefits of this modality, as well as a diversity of educational resources associated with their product, The 80-Lead Prime ECG. Obviously this is not without conflict of interest, but their “occult STEMI” cases are quite interesting.

Highlighting Pacemaker Activity 

Four lead placement variants used to better visualize pacemaker activity:

Images retrieved from:
Appendix A, RCA vs LCX in Inferior Wall STEMI
Image retrieved from, Eskola et al. How to Use ECG for Decision Support in the Catheterization Laboratory – Cases With Inferior ST Elevation Myocardial Infarction. Journal of Electrocardiography Vol 37 No. 4 October 2004

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s