wide complex sinus rhythm
First Glance:
From across the room it looks like regular wide complex rhythm.
Discussion:
The complexes are wide in both leads, with regular positive P waves before every QRS in lead II.
Half way through the strip we see a premature beat. In the chest lead it is almost identical to the sinus beats, but in lead II instead of an S wave it has a deep ST and a long repol phase. Is this a PVC or an aberrant beat? Against PVC is the fact that the chest lead morphology is normal.
The early beat has a spiky P right before it in lead II, but with a short PR interval. This sounds a bit like a PJC, but the P wave is upright in II which is normal. We would expect a retrograde-depolarization of the atria to produce a negative P wave if this beat originated in the AV node. So is it a PAC?
Further skepticism that this is a P wave right before a QRS is that we are at a gain of 50%, which would mean that at standard calibration that possible premature atrial depolarization would have had a positive deflection of around 6mm, which is huge compared to the subtle native P waves. Heck, this thing is the same size as the QRS.
I’m not sure what to make of this, so I’m wondering whether that spike before the early QRS in II is artifact, and the early beat could be fusion or aberrant supraventricular or PVC.
Final Impression?
Wide complex sinus rhythm @ ~90 bpm with one premature beat.
Management implications:
Get a 12L. Compare to old EKGs. This could be a BBB and there could be ischemia.
The Take-home Point:
Whenever you see wide complexes it is intuitive to check old strips and 12L EKGs for morphology changes. New wide complexes suggest progressive cardiac disease. But you can also have axis changes in narrow complex EKGs that would suggest similar problems. Comparing the current 12L to old 12Ls takes seconds but is incredibly useful in picking up changes.
The limb leads are always going to be stable from 12L to 12L (barring interval cardiac changes like infarctions, etc), but the chest leads are very position dependent. For that reason, be careful making big management decisions based on subtle changes in 12L chest lead morphology, as a less-than-exacting provider may have just slapped them on in a haphazard fashion. In fact, in my experience, they are always slapped on haphazardly, honestly.
One star strip. Students should identify the rhythm correctly.