RBBB and LAFB. Is it trifascicular block? The complexities of Wenckebach, with Ken Grauer analysis.

This patient presented with complications of his dialysis fistula.Medical history:History of Ischemic Heart DiseaseHistory of Congestive Heart FailureDiabetes Mellitus requiring treatment with insulinPre-operative serum creatinine>2 mg/dLHe had this ECG recorded:What do you think?There is AV 2nd degree AV Block (Mobitz I, Wenckebach) with RBBB and LAFBThe physicians recognized the RBBB and LAFB, but not the Wenckebach. They compared to a previous ECG and thought they were identical.  Here is the previous ECG from 2 months prior for pre-op for cataract surgeryThis appears to be atrial fibrillation with RBBB and LAFB.  I don ' t see P waves and of course Wenckebach requires P-waves.  See Ken ' s interpretation below.Are these ECGs of similar risk?I could not find a single case report of Wenckebach with RBBB and LAFB, so I don ' t know the risk.However, 1st degree AV block with RBBB and LAFB carries the misnomer of " trifascicular block " and portends complete (3rd degree) AV block, and mandates admission if the patient presents with syncope.If the patient does not present with syncope, then outpatient management is probably OK, with referral to cardiology.Interestingly, the patient presented multiple times in the next months with these Wenckebach ECGs which were not recognized:This was interpreted as " First Degree AV Block " .  But it is Wenckebach.This was interpreted as " First Degree AV Block " by a cardiologist.  But it is Wenckeb...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs