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Fascicular tachycardia

Wide-complex Tachycardia: Ventricular Tachycardia

Tue, 06/14/2016 - 14:23 -- Dawn

This ECG is from a man who was experiencing palpitations and light-headedness with near-syncope. On first look, you will see a wide-complex tachycardia (WTC) with a rate around 240 per minute.  It is difficult to assess for the presence of P waves because of the rate and the baseline artifact. 

 

The differential diagnosis of WCT includes ventricular tachycardia and supraventricular tachycardia with aberrant conduction, or interventricular conduction delay (IVCD). We should ALWAYS consider VENTRICULAR TACHYCARDIA first.  If the patient is an older adult with structural heart disease, WCT almost always proves to be VT. 

ABERRANT SVT?   In the setting of SVT with wide QRS, the most common aberrancy is right or left bundle branch block.  This ECG could be said to have a “RBBB” type pattern in V1, rSR’ and in Lead I and V6 with a wide S wave.  However, the other precordial leads do not have a RBBB pattern. 

VENTRICULAR TACHYCARDIA? There are some features of this ECG that favor the diagnosis of VENTRICULAR TACHYCARDIA (VT).  They include, but are not limited to:

* Regular, wide QRS complexes, about .14 seconds in this ECG, but varies because of difficulty in measuring the beginning and end of the QRS in each lead.  The artifact obscures the exact points of beginning and ending. The QRS complexes, especially from V2 leftward, are very “ugly”, and don’t resemble patterns we would expect with bundle branch block.

* Horizontal plane axis extremely abnormal:  Leads II, III, and aVF are negative and aVR and aVL are positive.  The biphasic Lead I indicates a nearly vertical axis at around – 90 degrees.

* There is “almost” precordial concordance, but V1 is biphasic. 

Unfortunately, we do not see capture beats or fusion beats, which would secure the diagnosis of VT. Disassociated P waves would also be a sure sign of VT, but the artifact in this ECG makes it impossible to say whether there are P waves. 

Wide Complex Tachycardia: V Tach

Sat, 06/02/2012 - 14:02 -- Dawn

This wide complex tachycardia occurred in a 91 year old man with a history of atrial fibrillation. He complained of "fluttering" in his chest, and denied chest pain or other problems.  While the paramedic attempted to start an I.V., he spontaneously converted to atrial fibrillation with left BBB, and PVCs.  Once he converted, his symptoms abated.  Remember, all wide complex tachycardias (WCT) should be treated as V Tach in the field, as this is by far the most common WTC and the most dangerous.

Some of the ECG clues that this WTC is ventricular tachycardia are:

* Monophasic upright QRS in V1  (does not have RBBB pattern of rsR')

* Extreme left axis deviation (II, III, and aVF are negative, I, aVL, and aVR are poisitive)

* V6 is negative

 

For a more thorough discussion of the ECG signs of V Tach, go to Jason Roediger's Ask the Expert page discussion on the topic:

http://www.ekgguru.com/node/157

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