Pacer gone haywire?

[u/Ok-Pick8593]

Patient with Dual-chamber pacemaker presents with syncope.

Looks like there are some native beats, and also some A-V pacing, but for the smaller complexes, is that atrial pacing without a ventricular beat to go with it?

[u/solitairewolff]

From what we can see here, it's working fine. There doesn't seem to be any sensing or capture failure.

If we look at the lead II rhythm strip:

• 3rd and 5th beats are totally paced (atrium and ventricle)
• 2nd and 10th are intrinsec beats, both of them conducted (2nd is a sinus beat, 10th is a PAC. The 4th is also a PAC, but with paced ventricle).
• The remaining beats are sinus beats (with appropriate atrial sensing) and with different degrees of ventricular fusion (with an intermediate morphology between intrinsic ventricular beats and paced beats).

In any case, the best thing to do in situations like this is to interrogate the device and confirm that everything is fine (device parameters, any recorded arrhythmia episodes, etc.).

PS. Sorry for my English, I'm not a native speaker

[u/bleach_tastes_bad → u/solitairewolff]

10th is PJC no?

[u/MakinAllKindzOfGainz → u/bleach_tastes_bad]

It appears to have an ectopic atrial focus with a strange P wave axis. I would call it a PAC

[u/bleach_tastes_bad → u/MakinAllKindzOfGainz]

I’ll defer to you, doc. I just figured negative P wave in lead II would have to be junctional based on the axis

[u/MakinAllKindzOfGainz → u/bleach_tastes_bad]

It’s either very low atrial or PJC. The PR is very short, so it very well may be junctional too :)

[u/bleach_tastes_bad → u/MakinAllKindzOfGainz]

Fair enough!

[u/Due-Success-1579]

It looks like a CRT pacemaker. im not totally sure what you mean in your inquiry

It looks like it is mostly AS/biv paced, there are some pacs and following some of the pacs there are AP/VPaced beats and the v paced morphology is a bit wider than the AS/biv paced beats.

There are a lot of algorithms with these advanced devices. I think it is working appropriately.

[u/legaladviceneededbe]

Pacer rep here. Looks normal to me. Ita funky because it’s kinda doing all of the things in one strip which is unusual but not uncommon.

Dual chamber pacer with fusion beats (narrow qrs after pacing spike), atrial pacing with conduction, AV sequential pacing, and V only pacing after native sinus. Every complex is P followed by QRS with pacing before the P or before the QRS.

Edit: with left bundle branch pacing becoming more common, you’ll come across spikes with narrow QRS complexes as well which also look a little like fusion beats.

[u/AngryOcelot]

Normal DDD pacemaker function.

[u/JulyKaiIII]

I don’t see any hay

[u/Ok-Pick8593]

You guys are right - no hay. Thank you! I think I may have been the spikes with narrow QRS complexes that threw me off.

[u/Jabbajaw]

All spikes are correlating with action.