Kardia home EKG, missing P-wave, and my PM

pacers and ekg

by Tracey_E - 2022-02-25 17:21:13

Pacers make the ekg very difficult to read and we will almost always show abnormal.  I'm not sure how Kardia differs from ekg at the doctor's office but it should pick up the pacing spikes. They are huge, hard to miss!

Kardia home EKG

by Daedalus - 2022-02-25 18:00:12

I had and used the Kardia 6L device several times and it correctly picked up my AFib attacks.   I then had a PM implanted (3 weeks ago) and was curious about it possibly interfering with the pacemaker.  I contacted the Kardia maker and they told me the pacemaker could interfere with it, not vice versa.  To quote their response:

<< Yes, a pacemaker can cause interference with recording on the Kardia devices.

Kardia products have not been tested for accuracy with paced-EKG recordings. We do not recommend the use of Kardia products for patients with pacemakers, ICDs, or other implanted electronic devices because we cannot guarantee the accuracy of the resulting EKG recordings. >>

Too bad.  Neat little device. 

What do tracing look like

by sgmfish - 2022-02-25 20:06:48

Thanks for the feedback. It doesn't surprise me that Kardia disclaims use with PMs. I have no doubt their point of view has to do with testing and liability. Kardia read-outs claim if you have sinus, brady, or tachy rhythms. They ain't endoursing those claims for PM patients.....not with a 10 foot pole <grin>. But that don't mean that the tracings aren't still useful wihen you have a PM. My question is technical, and I think their answer is legal/liability.

And when you mention "spikes", I assume you mean the QRS complex. Yes indeed, those are VERY easy to see (PM or no PM). I'm talking about the P-wave that preceeds the QRS complex. It is a small bump in the EKG trace that is not so easily seen even with a full blown EKG machine (same with the subsequent T-wave).

Are you looking for a new arrhythmia diagnosis?

by Gemita - 2022-02-26 05:00:25

sgmfish, although Kardia Mobile has not been fully tested for use with pacemakers, I feel any Kardia report we generate will still be helpful for our doctors. I believe it is possible to change the Kardia settings to produce a longer recording period (from say 1 minute to 2 mins), and this would give our doctors more info to confirm any irregularities.  A skilled technician reading a ‘paced’ rhythm from a Kardia mobile tracing should have no difficulties determining the rhythm disturbance present.  

I largely go by “how I feel” nowadays rather than using home monitoring to confirm an event and can quickly recognise the symptoms of an arrhythmia like A-Fib, since my symptoms alone when out of normal sinus rhythm, are usually diagnostic.  I always feel my pulse to confirm whether my rhythm disturbance is regular or irregular, fast or slow and I know immediately when my disturbances start and when I slide back into blissful normal sinus rhythm.  

In my experience, a surface ECG at the time of an arrhythmia is often required to confirm the arrhythmia present, although a 12 lead, surface ECG doesn’t always get it right and needs to be confirmed by an experienced technician.  My 12 lead surface ECG once confirmed frequent premature ventricular contractions and when read by my cardiologist, was confirmed as frequent premature atrial contractions with aberrant conduction (right bundle branch block pattern). 

On another occasion my pacemaker downloads showed I had had 18 recorded fast Atrial and Ventricular episodes.  One technician said the pacemaker recording showed SVT with 1:1 AV conduction, then fast AF but the Medtronic rep said it was likely Multi Focal Atrial Tachycardia and stated "This is an AEGM and the signal representation is sensitive to how much slack you have with the tip/tissue interface, to be more conclusive the rhythm should be verified with a surface ECG", so I can imagine the potential for interference and error during monitoring with home devices.

For a definitive diagnosis, longer term monitoring would be helpful.  I was fortunate and had an implant monitor for three years which really gave important information that would otherwise have been missed.  I hope you get the answers you are seeking.  Have a look under "Q" and type in Kardia in the search box.  There are quite a few posts to read.  I attach one such link:

https://www.pacemakerclub.com/message/37329/will-kardia-or-similar-show-atrial-pacing-vs-ventricular-pacing

pacing spikes

by Tracey_E - 2022-02-26 11:51:06

Nope, I mean a spike on the report from the pacer's signals.

https://ecgwaves.com/topic/ecg-pacemaker-rhythm-malfunction-failure-tachyarrhythmia/

Tracey_E

by Gemita - 2022-02-27 07:27:58

Thank you so much for your helpful link.  The pacer spike is unmissable!  So is the ventricular pacing with wider QRS complexes with the appearance of a LBBB.  After reading the link you posted and checking out a few You Tube videos on paced ECGs, I think the picture is slowly becoming clearer.  But what a study and I will need to keep returning to it. But not today, the sun is shining and I need to clear my head. 

Tracey_E and Gemita

by sgmfish - 2022-02-27 22:50:23

Following Gemita's links I found a strip that shows the "spikes" you are talking about. The strips from my Kardia-Mobile does NOT show any such spikes. I have no idea why.

Thanks for all the info. My interest is not actually to diagnose something, or to catch an episode, or anything like that. I just have the Kardia device from well before the PM was installed. Over the years I've educated myself to "read" EKGs (lots of education available on youtube) just for interest sake. I'm kind of a science-y guy and just like data etc. The Kardia does an amazing job for a 2 lead device. The manufacturer doesn't claim it can demonstrate to you AV blockage patterns and other complex conditions, but if you know how to read the strip it produces, you can see LOTS more than they are willing to advertize the device can do.

I just struck me as curious that I no longer see the P-wave now that I have the PM. Next time I go to the EPs office, I will ask one of the techs why I don't see the spikes or the P-waves. It's just scientific curiousity; I have no concerns.

Please let us know what the technician says

by Gemita - 2022-02-28 04:35:04

sgmfish, I have seen ECG tracings of an atrial pacemaker with "tiny" pacing spikes, followed by a "minute", almost invisible P wave.  

Providing you feel okay and don't suspect any kind of output failure from leads or other causes, then you should be seeing some pacing spikes/P waves, especially since you are 100% paced (unless your atrial rate intermittently is well above the preset level and your natural pacemaker is doing the work)?  But then you should see P waves.

If you are getting absolutely no evidence of having a pacemaker, perhaps this is confirmation that Kardia recordings cannot be relied upon.  Overall though, your experience with Kardia mobile seems to have been such a positive one, so I would be very interested to hear what your technician has to say about this and whether he/she feels Kardia is useful for pacemaker patients?

Atrial Pacing and Pacing Spikes?

by Marybird - 2022-02-28 05:54:12

Just a question here. If a pacemaker is pacing the atrium, say in a person with SSS, wouldn't there be a P wave as the atria respond to that "zap" by the pacemaker? And if the conduction system/AV is normal, so that in response to the atrial pace the ventricles contract normally ( ie, not paced), wouldn't the QRS complex seen on a surface EKG look pretty normal ( assuming no heart block, arrhythmias going on, etc) 

I've only had a couple EKGs- not even 12 leads, just 3 leads hooked up to a monitor, in the 2.5 yrs I've had my pacemaker,( one trip to the ER for a broken wrist, large goose egg on my head as I banged it into a sliding glass door during the fall that broke my wrist, and later surgery on that wrist), but in my unexpert opinion, those EKG patterns on the monitor looked pretty normal, P waves ( albeit varied in their morphology, and some pretty small, seems to me) and all. I also didn't see any pacing spikes I could identify,,despite numerous remote and some in-office device checks reporting atrial pacing between 91 and 95% for me. 

Apparently the voltage for my leads are set to the lowest setting ( have been since day 1), and they tell me my heart responds well to the zaps at those low voltages. I wonder if those lower voltage zaps might show pacing spikes that are much smaller, perhaps small enough to be inapparent, on an EKG? Because I wasn't able to see any ( neither was a nurse I asked about it, just out of curiosity- though she didn't spend much time looking) on those monitor EKG tracings when I was hooked up to it.

I don't know much about the Kardia, but from what I've read about the two lead handheld heart monitors, they don't pick up pacing spikes, typically, and the small print on the advertising and brochures for these devices does include disclaimers about the accuracy of their readings for people with pacemakers. Might just be CYA on their part, but it does bring these things into question. 

Kardia and P-waves

by AgentX86 - 2022-02-28 16:28:49

I don't know exactly how a Kardia works but it's not recommended for those with PMs and AliveCor makes no bones about it.  Clearly they're not designed for PMs but it may also be just CYA. There is another possibiity, though just a guess. Pacing spikes are huge compared to the normal electrical activity of the heart. EKGs sometimes blank right after a pacing spike is detected to keep the spike from overloading the front end of the EKG.  P-waves come immediately after the pacing spike so it's possible (?) that the P-wave is being hidden.  Just a WAG.

Pacing.

by PacedNRunning - 2022-03-05 01:40:05

Atrial pacing via Kardia shows flat P waves. I get it all the time paced. I have a mixture of paced and non paced. Just how it looks in Kardia or Apple