Sinus with aberrancy
First Glance:
From across the room it looks like a bizarre narrow complex sinus rhythm.
Discussion:
This is a ‘V’ lead, which could be placed anywhere, so it is hard to interpret specifically. We see a positive P wave with a hyperacute-appearing T wave, and some ST elevation.
But wait. What’s the gain? Here we see we are at 200%, so the big P is actually normal, as is the T, and the ST elevation is probably just under a millimeter. That’s a big difference.
Not explained by the gain is the spiky aberrancy seen in the QRS. This lead actually has what might be termed an rsr’s’r” pattern, which is nonspecific here. If this lead was in a septal position we might wonder about an incomplete RBBB. If it was in a lateral position we might wonder the opposite. This kind of choppy bizarre morphology can be caused by injury, old infarction, and post-surgical conduction changes, or in transplanted hearts. It isn’t normal, but it isn’t necessarily functionally pathologic. Unfortunately it makes the QRS harder to interpret in terms of standard voltages for chamber abnormalities.
Final Impression?
(presumably) narrow-complex sinus rhythm @ ~85 bpm with nonspecific conduction pathway delay, likely with insignificant ST elevation.
Management implications:
Check where the V lead is placed. 12L to evaluate for ischemia. compare to old 12L. changed morphology could imply new ischemia/infarction or anatomical changes (injury, displaced device, etc).
The Take-home Point:
Check the gain on the monitor before you make a final decision. Unlike on a 12L (where the gain is left at standard almost all of the time) the gain on the telemetry box is constantly being fiddled with by nurses, doctors, and med students who want to optimize the view for either visual interpretation or monitor interpretation.
We are all familiar with the false findings associated with gain that is too low. The strip looks like a low-voltage pattern, T waves look flattened, P waves are not visible, ST changes are minimized or appear absent. There are similarly false findings with gain that is too high as we saw in this strip.
‘Too high’ is probably not the right term. This is actually a good gain setting for this strip to visualize well the cardiac activity, but we must be cognizant of the subsequent changes in the morphology.
One star strip. Students should identify the rhythm correctly.