However, if your not willing to trust you equipment you'll end up hanging ami on a paced rhythm one day. I've seen it happen. For all of the "treat the patient" BS that exist out their, modern cardiac monitors are pretty dang good. The distrust that exist, and continues to be taught, is often misplaced blame from a bygone era. There are times you absolutely WILL NOT see a spike through the filtering software. As pacers get better, you'll see it less and less.You can't always think that just because the monitor is showing arrows means it is the holy grail of pacemaker detection.
What I gave was an incredibly oversimplified explanation. Someone once gave me a much more detailed rundown on the ins and outs of modern pacers....and I've forgotten most of it in the ensuing years.Furthermore if it is set to a specific R R interval; it is the same as pacing at a specific heart rate and the heart rate should be constant regardless of how often the pacer has to pace. This is further indication that these are PVC's.
Me too, BUT...the times I've seen this have been randomly and oddly spaced, never correlating with "PVCs" (by your argument there's a bit of artifact at the same point before every PVC that the machine is sensing as a pacer spike? Unlikely). Furthermore the morphology of the ventricular beats appears similar to most of the paced beats I've seen lately. Deep S wave, slight elevation above the baseline of the ST segment, no it's not something I can say is an absolute, but pacer beats, at least in my very anecdotal experience all appear "similar".I have seen the monitor show arrows in patients who had no pacemaker and it was simple artifact.
All of these are 15 years old. Pacemaker technology and monitor technology has come a LONG, LONG way in 15 years. Back then you were looking at LP10s, very few prehospital 12 leads, non-sensing pacers being commonly, no atrial pacing, ect. It's like comparing a 1997 car to a 2011 car. Not really easy to do.Here are some pacemaker strips, yes not all will show pacemaker spikes on the monitor, but most do.
http://library.med.utah.edu/kw/ecg/image_index/index.html
Scroll down to (9) artificial pacemaker strips
That said, I could be wrong, cardiology is not a particular area of special interest to me.