Junctional Rhythm: Fusion Trigeminy

Report:

Junctional rhythm 65/min

Left bundle branch block

VEBs in trigeminy, late-diastolic

Ventricular fusion beats

Comment:

The junctional focus appears protected from the VEBs; the pauses are fully compensatory. The morphology of the junctional beats is that of a true LBBB; a similar idioventricular rhythm would have a slurred S descent in this lead (MCL1)

Because the VEBs are so late, some junctional beats contribute to ventricular activation, producing fusion complexes (last upright complex in the upper strip and all three in the middle strip). These VEBs may well be arising from the distal (unblocked) part of the left bundle branch. The LBBB rS and the VEB qR complexes retain, in fusion beats, the initial Q of the VEBs. 165. Maximum DC countershock (marked X) in a 45 year old man with extensive anterior infarction. Three things happened next.

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