VEBs: Retrograde Conduction

Report:

Sinus rhythm

VEBs, trigeminal, uniform

Retrograde VA conduction

Left atrial abnormality (LAA)

Borderline right atrial abnormality (RAA)

Probable old posterior infarction

Nonspecific ST/T changes

Comment:

The compensatory pauses are longer than two sinus cycles, despite the obvious retrograde conduction, which should render the pauses incompletely compensatory (like with SVEBs). This is due to post-ectopic sino-atrial depression (overdrive suppression), delaying the SA discharge. Any prematurely depolarised pacemaker may show this phenomenon. It is one of the factors making the compensatory pause such a poor discriminator between VEBs and SVEBs.

The posterior MI is evident from the broad primary R wave in V1 (>0.04”), even if the R/S ratio remains below 1.0. The T wave is upright.

The P wave axis of +70o is probably significant in this patient with COAD; it is an early sign of pulmonary emphysema136.

Below (Fig 189a) the single VEB has no retrograde conduction.

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