Rapid SVT With RBBB Aberrancy

Report:

Broad-complex, probably supraventricular, tachycardia 270/min

?Atrial flutter with 1:1 conduction and RBBB aberrancy

Comment:

The initial QRS looks normal in all the leads, while the late forces could “pass” for RBBB; the axis appears indeterminate in the limb leads. Very fast rate like this favours an SVT, too.

Below (Fig 62a) is the sotalol-revealed atrial flutter at a rate somewhat slower than the original tachycardia (cycle length 240 ms, vs. original 220 ms). Thus the diagnosis of SVT or, rather, atrial flutter, appears quite likely.

The patient was referred for EPS with view to catheter ablation, but neither flutter, nor SVT, nor VT could be induced; he had runs of ectopic atrial rhythms and RBBB aberrancy, often sustained. The diagnosis is therefore as stated above. He remained well over the follow-up of 7 years.

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