We continue with the 2nd EKG from our patient last week:
And a quick refresher on the patient’s original EKG:
The good news is that it’s gotten narrower. The bad news is that it’s gotten considerably faster. The rate is about 120 on the original EKG, now the rate is in the 180’s. I’m going to be completely honest, I’m not sure I have a convincing answer with regards to the rhythm. The first question is narrow or wide. It certainly looks wide in some leads, but in other leads it looks narrow. That’s generally an argument that it is a wide EKG but the hyperkalemia may still be present and artificially widening a rhythm whose source is supraventricular. A couple of you asked if this could be a baseline LBBB (hey, thanks for paying attention a few weeks ago!) and at least one person thought the uber-wide inferior leads actually represented a STEMI with tombstones in a patient who’s about to code.
There is a clue though, that I think the underlying rhythm is narrow. Look again at the V1 rhythm strip:
There’s a PVC looking complex considerably wider than the rest of the beats. I think that if this was as Vtach that it would be unlikely to have an additional even wider ventricular beat. However, a counter-argument would be that the polarity of the PVC is very similar to the rest of the EKG’s polarity arguing it’s coming from the same area.
Even if this is V Tach, amiodarone in hyperkalemia is still a bad idea. We considered shocking her, but I felt we had time to trial adenosine (while frantically sending off another basic to see where the electrolytes stood after a couple rounds of Calcium, D50, insulin, and bicarb). At a rate of 180 it’s not sinus tach and probably unlikely to be A flutter, though I will definitely grant that the V1 rhythm strip suggests flutter waves. There’s another entity, however, that we haven’t discussed in this setting, and that is Atrial Tachycardia. Essentially Atrial Tachycardia is SVT that isn’t coming from the AV node. It will look basically identical to SVT but won’t respond to adenosine.
What happened when I gave the adenosine? Well initially nothing which perhaps makes V tach more likely, Atrial tach definitely more likely, but SVT still possible. Two minutes later however, she converted to the final EKG in the series. And hopefully you’ll agree that her final EKG will more than payoff a somewhat unsatisfying EmpireStrikesBack-like middle installment of a 3 part series.