Looking through the smoke screen

In honor of our Armed Forces and Memorial day, here’s a picture of the Coast Guard doing some exercises on the pier from a few years ago.  My generation is probably the first American generation not to be a part of a war that mobilized large segments of the population.  As part of that majority who hasn’t served all I can do is acknowledge the service and sacrifice of those who have.  So Thank You.

What does this have to do with today’s EKG?  Well, let’s dive in.

60 y.o. man with a cough, please interpret EKG

Rate is fairly straightforward, it is right around 60.  There is a PVC.  What of the rhythm?  Aside from the PVC it looks fairly regular.  We see a lot of chatter in this EKG.  Does that mean that it’s A fib or flutter though.  The EKG is regular which makes A fib a lot less likely.  A flutter can be regular but it would be unusual to have such a consistent R-R interval, usually there will be a few R-R intervals that are different multiples of the flutter waves.  This EKG is very consistent in its R-R intervals, but very inconsistent in the appearance of the apparent flutter waves.  Flutter waves are generally very stereotyped, and usually one big box wide (they can sometimes be smaller).  In this EKG we see all sorts of different sized deflections.  Are there actually P waves underlying all this smoke?  Let’s zoom in on the V1 rhythm strip.

20180522_nsr zoom

In fact there are P waves there.  It would appear that all the baseline business is just artifact.  It’s impossible to know the source of the artifact, this could be muscle tremor from shivering to go along with his fever.  He might have Parkinson’s.  Maybe there’s some interference with the EKG.  In any case, the patient doesn’t have Afib/flutter.

Finishing up the interpretation of this Normal Sinus with Artifact EKG, the PR interval looks reasonable.  He has a Left axis (up in I, down in aVF).  The P waves are a little biphasic in V1, he probable has some left atrial enlargement to go along with the presumed hypertensive heart disease that led to the left axis.  QRS is a narrow though the precordial R wave progression is a bit on the slow side.  There does appear to be some flattening of the T waves, and I almost get a sense of mild QT prolongation, though that’s difficult to prove.  As always an old EKG might be useful.

Take-homes from this EKG?  Always ask yourself if things make sense even if obvious.  At first glance this EKG looks like A fib, but the regularity should stand out.  The regularity might lead a person to choose A flutter, but again, flutter waves are very stereotyped, these aren’t.  Finally, the rhythm strips are where P waves are best seen, this EKG is another example of them coming out most strongly there.  Finally, fake A fib is a common topic on board exams since they don’t want us anti-coagulating people without a reason.

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