WCT

This is a good example of ventricular tachycardia with PRECORDIAL CONCORDANCE.  The QRS complexes in the chest, or precordial, leads all point downward.  When the precordial leads are all  negative or all positive in a wide-complex tachycardia, there is virtually a 100% chance that the WCT is ventricular tachycardia.  This ECG shows many characteristics of VT, including the extreme "backwards" axis:  aVR is positive and II, III, and aVF are negative.  Lead I is almost equiphasic.  Also, the lack of a clear BBB pattern and a negative V6 are strongly suggestive of VT.  REMEMBER:  In the treatment of wide-complex tachycardia, the rhythm should be considered VT unless proven otherwise.  This is especially true in unstable patients, patients over 50 years old, and patients with known heart disease.

INSTRUCTORS' NOTE:  We purposely left the machine interpretation on this week's ECG of the Week.  How many errors did the machine make?  This might be a good teaching point for students of all levels.

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.
   

This ECG was submitted by Sebastian Garay, EMT-P and ECG Guru (and ECG Guru Member sebmedic). It is a very interesting case of wide complex tachycardia in a patient with Wolff-Parkinson-White.

This is from a 57 year old man who sought medical help for a complaint of palpitations. He was known to have WPW. The paramedics determined that he was hemodynamically unstable, and in light of the wide-complex tachycardia, they performed a synchronized cardioversion at 100 j. The patient converted to the rhythm shown in the next ECG. The paramedics then administered a Lidocaine bolus and drip, considering this to be a ventricular tachycardia. The patient arrived in the Emergency Dept in improved hemodynamic condition.

This ECG can be used to teach V Tach for beginner students, WPW and WCT tachycardia differential diagnosis for more advanced students. It is also a good ECG for axis discussion, and for how lead placement affects the final product.

The differential diagnosis here is 1) V Tach and 2) SVT with aberrant conduction or left ventricular conduction delay. For a discussion of ECG criteria which help us diagnose WCT, see the "Ask The Expert" column from Jan. 11, 2012. Characteristics that make this look like V Tach include: wide complex and significant left axis deviation. Features which may favor a diagnosis of SVT are the pre-existing WPW and a rate of 222/min. There are no p waves seen. NOTE: V2 in this ECG appears to reflect electrode mis-placement, as it does not "make sense" in the normal progression of the QRS complexes in the precordial leads. It is clearly "out of place".

The second ECG shows the same patient after conversion of the tachycardia.  The delta waves of WPW are easily seen.