EKG of the Week
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+ EKG Interpretation
Dr. Ohlbaum's Explanation
This is an interesting EKG because something (the rhythm) CHANGES during the 10 seconds it is recording.
Start at the beginning. For the first 2/3 or so of the tracing there is a regular (or almost regular) rhythm at a rate of about 100 with a P before every QRS and a QRS after every P wave. So that is sinus rhythm with just a little sinus arrhythmia. The QRS during that early part is just a little wide (right at 120 msec consistant with the RBBB that we can look at a little later). Then there is a beat that looks like a PVC and then it all changes. What are we looking at? It is regular and wide (wider than before, around 160 msecs) at a rate of about 200. The QRS morphology in the leads that are all the way across the page (ie in the rhythm strip) is very different from the earlier morphology.
The differential is VT vs SVT with aberrant conduction.
It is hard to be sure about Brugada criteria when you only see a few leads, however, the key here is that the P waves continue to march through at the same sinus rate! (That's the third criteria of Brugada)
Tracing there is a RBBB with an RSR' in Vl, and broad Sin I and AVL. There are also Q waves in the inferior leads (II, Ill, and AVF) and deep T inversions in those leads all consistent with the recent but not acute inferior infarct that this patient had. So, sinus rhythm that is followed by a PVC, then VTACH (not sure if sustained or not on basis of this EKG since we do not see it end). He has a RBBB and a recent (but not acute) inferior Ml.
