Rhythm Nation February 2015

emergencydrb · February 18, 2015 at 2:43 pm

So, I don’t think I really have the whole answer, but I’ll go with what I got since I spent some time on it.

What could this rhythm be?
The rhythm appears to be some type of ventricular tachycardia given an irregular tachycardia at a rate of 110’s-130’s with most notably complete A-V dissociation with regular P waves, but no capture beats or fusion beats. The QRS is slightly widened at 100-120ms with left axis deviation and negative concordance in the precordial leads (all the precordial leads are negative). So, this rhythm appears to be a type of fascicular ventricular tachycardia. With no RBBB morphology, looks like the only option left is a upper septal fascicular block because it looks more like a LBBB than a RBBB.

Why?
Here’s where I’m a bit shaky (or was I shaky in that entire paragraph above? don’t really know). I remember reading somewhere that if you have an accessory pathway (like in WPW) and the person is in A fib/flutter and you give them AV-nodal blockers (like adenosine) that it can send people into VT, so that’s gonna be my guess: that there’s a fascular block with an accessory pathway and it was initially a re-entrant SVT which after blocking the AVN is now a VT but with a fascicular block. (although, if the person was really activating through the accessory pathway initially with afib/flutter, her rate should’ve been higher and it should have been a wide complex tachycardia which doesn’t look like AVNRT, soooo yeah)