The patient was noted to be AV pacing more than 90% of the time.
Figure 1 - Lead II showing AV pacing
An rS lead configuration can be seen when patient is only atrial pacing.
Figure 2 - Atrial pacing with prolonged AV conduction and V-pacing
At a later point in monitoring (Figure 3), I noticed a difference in morphology in the QRS of the monitoring lead. At around 0150, we can still see atrial pacing with a prolonged AV conduction and a narrow rS configuration. The latter half of the strip showed wide QRS complex V-paced beat.
At 01:56, there is some widening of the QRS and the difference in the ST segment. At a later point (02:02), there is merging of the Q-ST segment.
Figure 3 - Time stamped changes in monitoring lead
These changes are better appreciated in full disclosure (Figure 4 vs Figure 5).
Figure 4 - Full disclosure at 0150
Figure 5 - Full disclosure at 0158
Side-by-side comparison of strips time stamped 0150 and 0158 (Figure 6). At full disclosure, there is generalized widening of the QRS (from leads I to aVF). I asked the primary RN to check the patient and noted that the patient has no pulse and breathing. This is a DNR patient.
Figure 6 - Side-by-side comparison in full disclosure (0150 vs 0158)
The take home message here is that, you should be like a child when looking at an ECG. You should understand the baseline strip by reviewing the old saved telemetry data and look for changes. I also advise you to look at the baseline and old 12 lead ECG if available. Do not forget that you have other leads to examine that is available in full disclosure. Do not rely on the usual lead II.
Using (ECG) telemetry in detecting physiological changes of a patient with a pacemaker takes time to master and demands careful observation.