Unlike Thanksgiving leftovers. Those can definitely get old.
Shout-out to Katie Clark for contributing this week’s EKG.
Let’s throw out for a moment that the patient is a child and just start with analyzing the EKG. Looking at the rate, we see a lot of busy-ness on the EKG, but how many deflections are QRS complexes? While children do have a very narrow QRS, no one has the dagger thin marks that dominate this EKG. Those extremely narrow deflections are pacer spikes. Looking at the lower 2 rhythm strips we see there are both atrial and ventricular pacer spikes. Looking at V5 we can count 5 QRS complexes, this rate averages in the 30’s.
We’ve already started addressing the rhythm, we do see pacer spikes. The problem is that nothing comes after most of the spikes. There’s atrial pacing marks … but no P waves. There are ventricular pacing marks … but there’s a big box and a half before the QRS is either triggered or escapes. So we have an extreme bradycardia with a pacemaker that is mostly, or entirely, failing to capture.
Let’s look further at the QRS. Did we mention early on that children generally have VERY thin QRS’s? Would a full big box wide be the opposite of that? Because that’s how wide the QRS is, again best analyzed in the V5 rhythm strip on this EKG. Do the T waves somewhat mirror the QRS? What’s more the T waves take so much time to occur the pacer is already putting atrial spikes atop the T waves.
Reviewing the clinical situation, it’s a 15 month old who’s lethargic after 3 days of vomiting and diarrhea. There’s poor conduction in the heart with a very wide QRS with T waves that have amplitudes roughly the same as the QRS. A lot of people keyed in on the diarrhea and proposed hypokalemia as the cause. Hypokalemia, however, usually shows flattened T waves. The vomiting, diarrhea, and whatever underlying heart problem was bad enough to require a child to have a pacemaker combined to cause renal failure. What happens to people in renal failure? Hyperkalemia. Does Hyperkalemia cause uber wide heart tracings and bradycardic arrests? You bet. This child was hyperkalemic to the tune of 12.
I’m going to keep running Hyperkalemia EKG’s. I just am. And you may think they’ll get old. But they won’t.