Killip-Gault Rule and Exception

Report:

Sinus rhythm and arrhythmia

SVEBs

9 beat run of (probable) atrial fibrillation

Rate-dependent bundle branch block, probably LBBB

Comment:

This is Lead 2 and one cannot tell with certainty that the IVCD is, specifically, LBBB. It looks like it, however, and the (aberrant) SVEB in 12-lead ECG (Fig 112a) confirms it.

P’ waves can be seen to precede LBBB beats: one disturbs the ascent of the T wave in the top strip, another the descent of the T wave in the bottom strip (first SVEB there). The second SVEB in the bottom strip is, again, on the ascending limb of the T wave, conducted with 1o AV block. The third SVEB in the bottom strip is normally conducted, both in the AV node and the ventricles: it is later-coupled than the others.

The SVEB starting a run of AF is has its P-P’ interval much less than ½ P-P interval; it occurs during the atrial vulnerable period and causes AF (Killip-Gault rule)100.

The second SVEB in the bottom strip is also very early, also has a P’-P less than ½ P-P interval, but does not demonstrate the rule. The rule does not always work.