EKG of the Week
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+ EKG Interpretation
Dr. Ohlbaum's Explanation
This EKG was done on an asymptomatic elderly patient with an irregular rhythm.
The computer called it atrial fibrillation. What do you think? Well, are there P waves? When I look at the rhythm strip (either V1 or II) I can see clear P waves that march through the tracing, so clearly NOT atrial fibrillation!
There are regular P waves so the atrial mechanism is sinus (The atrial rate is actually about 70 so not sinus brady). Are there QRS complexes? Some of the P waves are followed by QRS complexes but some are not, so 2nd degree AV block. Is it Mobitz I or II? Well the PR is short, then longer and longer until a QRS is dropped so it is Mobitz I.
Looking at the QRS, it is wide (140 msecs about right), why? There is an RSR’ in V1 and deep broad S waves in the lateral leads this is a nice example of a RBBB.
SO…
Sinus rhythm with 2nd degree AV block Mobitz I, and a RBBB.
Further Reading:
Life in the Fast Lane: Mobitz I
