I am an admitted ECG guru. I can look at these things for hours and hours on end. So I particularly enjoy getting a challenging, or different, one.
Sick dude’s 12-leads, with interpretation this time:
I agree and disagree with the interpretive algorithm here, which isn’t abnormal for me. I see atrial fibrillation, a right bundle branch block, and a right axis deviation. I don’t however, see any demand pacing.
Furthermore, complex #4 looks completely different than the rest of them, and it’s evident on the initial strip as well.
I am leaning towards a transient AV nodal block caused by the patient’s hyperkalemia. Hyperkalemia can certainly delay conduction through the myocardium, so I don’t believe my supposition be out of the realm of possibility.
Smarter people might disagree with me. But I’m okay with that.
So on to the patient’s second 12-lead, which the monitor spit out all on it’s own:
That’s cute. I chuckle a little bit every time I see those words “Pacemaker rhythm – no further analysis.” I take that to mean “Don’t really know what else to say.”
I certainly don’t think this is a paced rhythm at all. Those little pacer spikes at the bottom aren’t regular enough to be coming from a pacemaker, and frankly aren’t producing those complexes. This patient’s pacemaker was set at a back up rate of 70, yet the monitor thinks the pacer is firing at 50 times per minute.
What did happen, and I frankly can’t say why, is this man’s ECG changed from a right bundle branch block to a left bundle branch block. I have used my excellent cutting and pasting skills to elaborate:
I still use William Marrow to differentiate between right and left bundle branch blocks. Sure, I know that an rsR’ complex in V1 and S waves in V6 mean right bundle branch block, but I still use Ws and Ms.
“In a right bundle branch block, there is an “M” in V1 and a “W” in V6. In a left bundle branch block, there is a “W” in V1 and an “M” in v6.” WiLLiaM MaRRoW . I wish I could remember where I learned that, but it has long escaped my brain.
I don’t believe this guy is having cardiac issues, per se. I’m fairly certain saying that all his conduction problems are directly tied to his serum potassium, which was 7.7.
At the time of this writing, I still do not know the patient’s outcome.