The 12 Leads of Christmas: Lead III

This article is the third in our latest series, The 12 Leads of Christmas, where each day we examine a new finding particular to an individual electrocardiographic lead. Lead III Lead III is great at identifying STEMI’s. In patients presenting with signs and symptoms concerning for ACS but no clear ischemia on the initial ECG, it’s one of the three leads I usually choose to display on the monitor (the other two are aVL and V3). There’s three major reasons I like lead III in ACS. First, when a patient is experiencing an inferior STEMI, it is usually the lead that shows maximal ST-deviation in the form of ST-elevation. There’s a lot of ST-elevation, but lead III has the most.   It’s not as important when there’s giant ST-elevation, as in the case above, but when the ST-deviation is a bit more subtle it becomes vital that you know where to look. This inferior STEMI is a bit more subtle but lead III still has the most ST-deviation. This inferior STEMI is even more subtle but again lead III shows the most ST-elevation.   It’s no coincidence that lead III is great at identifying inferior STEMI’s. While it is commonly taught that II, aVF, and III are the “inferior leads,” lead III is really the star of the show. At an angle of 120 degrees, it is the lead best positioned to capture the bulk of the inferior, infero-septal, and infero-posterior walls. If you think of the ST-elevation we see in STEMI as a vector, meaning...
Source: EMS 12-Lead - Category: Cardiology Authors: Tags: 12-Leads of Christmas 360 Degree Heart Original Articles Vince DiGiulio Source Type: research