Bilateral Bundle Branch Block

Report:

Sinus tachycardia 113/min

Left anterior hemiblock

Right bundle branch block

Comment:

This is only a bifascicular block – complete right and partial left bundle branch block. The term BBBB is not usually used for this. But if, as here, the patient develops complete LBBB (Fig 40a), the diagnosis of BBBB can be made. It happened the same day. The patient remained in LBBB conduction ever after.

This means that the original RBBB was not an anatomical block. The right bundle took over all the conduction once complete LBBB occurred. The latter is divisional, with LAD inherited from the original trace. This confirms, some say, extra disease in the superior-anterior fascicle of the left bundle branch.

Fig 40a. Same patient with LBBB on the same day as previous RBBB.

Fig 41. 83 year old man with ischæmic heart disease and arrhythmias.

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