Wenckebach AV Block in Acute Inferior Infarction

Report:

Sinus rhythm 90/min

Möbitz 1 (Wenckebach) second degree AV block

Intraventricular conduction defect (IVCD)

QRS 0.12”

Acute inferior infarction

Comment:

The most striking feature are the marked precordial reciprocal changes, indicating extensive infarction.

The IVCD escapes easy definition despite RSR’ pattern in V1, where the secondary (R’) R wave is too narrow and is not associated with S waves in 1 or V6. The latter leads suggest incomplete LBBB, but this is excluded by the presence of normal septal q waves there. The term periinfarctional block is attractive, but is (rightly) no longer used.

A week later (52a) there is considerable voltage loss, but the diagnostic Q waves have not developed in the inferior leads. R wave loss is their equivalent. The AV block persists, although increments in PR interval have become invisible. The mysterious escape beats terminating the pauses are in fact pacemaker-sinus fusion beats, with the (bipolar) pacing spikes too small to see. This is clearer overpage, without fusion Fig 52b).

If you have any suggestions for or feedback on this report, please let us know.