Do these rock formations look like last week’s EKG at all? I’m in Yellowstone blogging about EKG’s; maybe I’m seeing tombstones everywhere. It’s possible (errrrrrr, highly likely) that I need a life, but that’s probably fodder for a different blog.
Here’s the quiz EKG again as a refresher:
They love to put non-STEMI causes of STE on the boards (I think I had 3-5 questions in that vein on my re-cert last fall) and this EKG falls into that category. You can see right away that I left the computer’s interpretation visible. Whether you look at that first or second (I recommend 2nd) you have to make sure that you’re seeing what the computer sees. In this case it’s focusing on the inferior leads which admittedly do suggest STE. But let’s not jump around. Have a system, use it!
Rate: It’s about 2 1/2 big boxes so between 150 and 100; the computer’s interpretation of 120 looks to be reasonable.
Rhythm: Here’s where it gets tricky. A significant number of you said sinus tachycardia and I think you were probably looking at the rhythm strip in II. There’s a lot of leads though (I, V1, V2) where typically a person can see P waves fairly easily; there’s no evidence of P waves on this EKG in those leads. Let’s look back at III, the source of the computer’s confusion:
Does III and aVF look a little saw-toothed to you? They should because this is Atrial Flutter. At least one of you commented that it seemed a little slow for A flutter and I agree, flutter waves are usually clipping along at 300 leading to a rate of 150, but not every patient reads this blog to know what they’re supposed to do.
If you don’t believe me then here is a follow-up EKG after getting a dose of IV lopressor to slow him down a little:
Zooming in on the rhythm strip in II we see this:
Here the lopressor brought at least some of the 2:1 conduction down to 3:1 conduction making the flutter waves much easier to pick out.
Moving right along to round out our interpretation, looking at the QRS complexes I think just about everyone noticed the RBBB morphology.
The ST segments are harder to evaluate given the presence of super-imposed flutter waves. A number of people felt that the twist in this case was S1Q3T3 and that PE, rather than STEMI, was the cause of the abnormalities. I don’t disagree that S1Q3T3 is present, but I think you have to first recognize that flutter is contributing to that appearance. I would have given credit for answers that included both; indeed PE is an uncommon cause of new onset A fib/flutter. For those who questioned posterior MI, I agree there is STD in V1 and V2. If you reversed and then looked through the EKG it would look like this:
Notice that it coves up, not over; so not a tombstone pattern. Obviously in early ischemia STE can cove up rather than over into tombstones, but this wouldn’t be a classic posterior MI at least.
The decision as to whether or not to tone this out as a STEMI and activate the cath lab is a hard one. You never want to miss a STEMI and that will by necessity mean there will be some activations that don’t end up as real. I did not activate the cath lab on this one but again if in doubt, get the EKG to your cardiologist prospectively and share the decision making!
And hopefully you won’t be activating the cath lab on me anytime soon; the kids paced us 2.5 miles up to the summit of 10,000 foot Mt Washburn yesterday, I’m still alive and kicking!