Cherchez le P!

Report:

Sinus rhythm

Second degree AV block, Möbitz 1

Acute inferior infarction

Comment:

The title is part Marriott’s famous phrase on how to tackle arrhythmias95; it paraphrases the once even more famous cherchez la femme, now squashed by the politically correct. Most of the P waves are in hiding, superimposed on T waves; they are best seen in V1. It is relatively easy to misread this trace as sinus rhythm with 1o AV block and SVEBs. The obvious inferior infarction should suggest the possibility that 2o AV block, rather than ectopic beats, is the cause of the irregular rhythm.

The presence of 2o block may be a marker of non-infarct-related (awful new word!) LAD disease in this setting96.

The QRS is somewhat prolonged, in the incomplete bundle branch block range (0.10 – 0.12”), but neither RBBB nor LBBB are present. It is hardly worth commenting, except to mention that periinfarctional block was once a popular diagnosis. It has no specificity and is hard to define or diagnose; it deserves oblivion.

Below is the real reason this case is included here: a sustained period of 2:1 block misreported – by me, during my routine reporting, as sinus rhythm 55/min with 1o AV block! I feel better already, having confessed to this! But the students should feel less good: quod licet Iovi…