Years ago, I was tasked with introducing 12-lead ECG interpretation to firefighter/paramedics who had been using ECG for rhythm monitoring for years.  Some were eager to add to their skills, others - not so much.  The feeling was, we have been doing just fine as we are.  When finally convinced that they could interpret STEMI with a 12-lead, many were content to use the 12-lead ECG only for that.  

To illustrate to students the great value of multi-lead assessment, I devised a little "quiz".  I showed the students ten to twelve short rhythm strips, like you see here.  All were cropped from 12-lead ECGs.  I asked my class to interpret the strips as they would if they were taking an ACLS class.  Usually, all did fine, or so they thought.  When shown the 12-lead ECGs the strips were taken from, EVERY student changed his or her mind on EVERY ECG.  The lesson is:  sometimes what we are looking for shows up in some leads and not others.  You can find this illustrated hundreds of times just in the ECG archives on this site.  I will supply some ECGs here on this page over the next few weeks that you could use to show your own students the value of "multi-lead assessment".  

What started as a hard-sell turned out to be a fun exercise.

The ECG shown here is of a patient in V Tach.  There are several strong signs that this is V Tach, including the wide QRS complexes, lack of associated P waves, "backward" axis, also called extreme right axis deviation (Leads II, III, and aVF are all negative and aVR is positive), and V6 is negative.  For more review of the differential diagnosis of wide-complex tachycardias, go to our Ask the Expert answer from Jason Roediger.  This LINK willl take you to Dr. Grauer's informative webpage where he offers a step-by-step guide to differentiating the WCTs.

 The focus of THIS lesson is that, while the patient is in V Tach, and it is in every lead, the tell-tale signs are harder to see in some leads than others.  Remember to show your  Remember to share with your students that the channels of the ECG (in this case three) are run simultaneously, so that the same heartbeat is seen several times - once for each channel.

Torsades de pointes, or polymorphic ventricular tachycardia, is a ventricular tachycardia precipitated by and associated with long QT Syndrome.  Long QT Syndrome can be congenital or acquired.  Torsades is life-threatening, and can be made worse by many drugs, including some of the drugs used to treat VT.  The rate is usually 150 - 250 / min. and the appearance is of a wide-complex tachycardia with QRS morphology changes.  In some leads, it will appear as if it is "twisting" around the isoelectric line, giving it the French name, Torsades de pointes, a ballet term meaning twisting of the points.  For a thorough discussion of Torsades, check this LINK.

This ECG was presented earlier this week as an example of SVT with LBBB aberrancy, which was ultimately converted with one dose of adenosine in the Emergency Department.  It is the most shared and commented on ECG yet to appear on the Guru.  The diagnosis given was the one accepted by the medical staff who cared for the patient, who was a man in his 30's who presented to the Emergency Department complaining of a rapid heart rate.  He was ambulatory with stable vital signs, in spite of the tachycardia. He reported that he has had several episodes of fast heart rate which responded to either Valsalva maneuvers or, in some cases, medication in the ED.  He was told he might benefit from an ablation procedure, but he did not have health insurance and continued to use the ED as his primary source of medical care.  When he was admitted to the ED, the tech initially called for help, thinking the monitor showed ventricular tachycardia.  The ED physician felt that this represented LBBB aberrancy, possibly rate-dependent, and he treated the patient with adenosine.  The rhythm converted to sinus after one dose, and the patient remained stable throughout the process.  He was advised to undergo further observation and testing, but he declined due to financial concerns, and the fact that he usually succeeded in relieving his symptoms with "bearing down".  

Wide-complex tachycardias can be difficult to assess simply from an ECG. The patient's stability depends more upon general health and cardiac output issues than the origin of the tachycardia.  When we presented this ECG, we also presented the diagnosis he had upon discharge from the ED.

Subsequently, ECG Guru Dr. Ken Grauer, a frequent contributer to this site, offered his alternative diagnosis and his explanation of why he believes this to be v tach.  Other well-respected ECG experts have also questioned the original diagnosis.  Please refer to the comments below for this very helpful explanation.  Unfortunately, this patient is lost to followup, as this incident occurred some time ago.

WTCs remain a most fascinating topic, especially for those who enjoy "detective work".  We thank Dr. Grauer, Tom Bouthillet, and others for their contributions to the ECG Guru on this topic.