I do my homework, the day I get it
and I put it in my bag so I don’t forget it!
Can you tell it’s back to school time? My wife makes the kids recite that mantra from time to time. Of course they still have to remember to take the bag with them to school, but no system is perfect. The important thing though, is to Have A System, because if there’s multiple things going on with an EKG you’re going to miss them. Case in point, this EKG:
You can clearly see inferior tombstones. And yes you should be calling your friendly neighborhood interventional cardiologist. But there’s something else going on in this EKG that should affect your treatment.
What’s the rate? It’s quite fast. It’s also hard to judge based on big boxes since it’s irregular. There’s 26 complexes though. If there were 25 complexes we’d multiply 25 x 6 and get 150; the rate is a little over 150 therefore. We’ve already said it’s irregular. Are there P waves? I can see how some people could sort of imagine p waves in some of the more widely spaced R-R intervals, but A fib can be mildly coarse and have some irregularity. The combination of significant irregularity with identical QRS complexes (if they were PAC’s/PVC’s the morphology would likely change) really can only mean Atrial fibrillation.
We already mentioned the inferior tombstones. There’s also significant reciprocal change to the lateral limb leads (I and aVL) and V2. A couple people noted that the V2 morphology could be consistent with a posterior infarct; they’re not wrong about that, but the tombstones in the inferior leads II, III, and aVF take precedence culturally in our description of an MI. This patient therefore has an Inferior STEMI in the setting of A Fib with RVR.
The significance of missing the A fib with RVR? Well, do you think it’s a good thing for your heart to be beating 2 or 2.5x normal in the setting of ischemia? Presence of a STEMI qualifies a patient as being unstable. We gave her aspirin. We started heparin after stat chest x-ray. We started her on fluids (remember inferior MI can involve the right ventricle and can be preload dependent, so be very cautious with nitro) and gave her something for pain. We then started her on amiodarone (as an aside I chose this instead of cardizem or lopressor as theoretically an inferior MI could be more likely to go into a heart block which pure AV nodal agents could exacerbate – but used a long acting drug that partially does that as well; maybe a short acting drug would have been the better choice) in the hopes it might work by the time we had the patient consented and prepped for a cardioversion while awaiting readiness of the cath lab (at 5 in the morning). The amio didn’t affect the rhythm, and after a conversation with the patient and family we sedated her with etomidate and performed synchronized cardioversion. Here’s the EKG about 20 minutes later just prior to going upstairs:
The ST waves are markedly improved. Interestingly she’s mostly in sinus but it looks like she may be trying to go back into A fib in the 6th and 7th beats of the EKG; the amio may be helping her stay in sinus.
You can see therefore the importance of looking at the entire EKG since there may just be 2 abnormalities.