Sometimes it’s best not to over-think things. This EKG is probably a good example. It’s pretty common on board exams to not even really need to look at the stimulus, you should have a pretty good idea of where the item writer is going with the question just with the question stem.
Similar to the previous EKG, let’s look at the clinical data to frame our minds first. There’s a murmur that decreases with squatting. Remember that squatting will force blood and lymph out of the legs and return it to the heart, increasing venous return. This patient’s murmur decreases with increased venous return. For the purposes of board questions there’s basically one thing that does that, HOCM. Most patients with HOCM will be on beta blockers as well to help slow the heart down and force the heart to pump more blood with each beat; this helps decrease the obstruction of HOCM as well. So do we see signs of HOCM on this EKG? Let’s look.
Looking at the rate, the QRS’s are about 4 big boxes apart, this rate is around 80. The lead I and II rhythm strips show clear sinus rhythm. The P wave is biphasic in V1 indicating some Left Atrial Enlargement. Axis is borderline left, it’s up in I but I think (barely) predominantly down in aVL. The QRS is narrow but there are massive voltages in V1. I put my pointer where the QRS in V1 stops 9(!) big boxes below the V1 baseline.
There’s also some repolarization abnormalities, some elevation of the J point in V1 and a lot of strain pattern STD and TW inversion elsewhere.
So to summarize, we have a patient who has a murmur that acts like a HOCM patient, a patient who got worse after stopping their beta-blocker like a HOCM patient, with an EKG which shows huge septal voltages and a bunch of repolarization abnormalities like a HOCM patient. The patient has HOCM. The cardiologist suggested (and by that I mean told me in no uncertain terms after questioning who the #*@% stopped her beta blocker) to re-start the beta-blocker and have her follow-up with him.