Movement Artefact Simulating VEBs

Report:

Sinus rhythm 80/min

Within normal limits

Movement artefact in simultaneous V4-6 & V1 strip

Comment:

The computer diagnosed a (single) VEB. If there were a single VEB, it would have been about 0.56” in duration!

It is easy to see, once thought of, that the first sharp spike is a normal QRS – dead on time – superimposed on the movement artefact. The second one is too close to the first one to be another VEB. The whole thing starts with a slow negative deflection that, superficially, mimes a T wave without a preceding QRS.

Below (Fig 233a) is another example, where a similar spike-on-time can be seen in Lead 1. This time it’s easy to see that both “complexes” are movement artefact, since simultaneous Lead 3 does not show them. The trace is of an 80 year old lady with chronic RBBB and NW axis secondary to a past inferoposterior infarction. It must be said that an SVT with her morphology would look like a VT.

Both tracings fooled the computer and, I am sorry to say, not a few humans.

233a. The artifacts “borrow” some of the patient’s T waves to make themselves look like authentic VEBs. Computer diagnosed VEBs and SVEBs.

234. 73 year old woman recently cardioverted by DC shock from atrial flutter, despite toxic digoxin level