Rate dropping below low rate setting

Dual lead pacemaker placed on 1/3/22 to address bradycardia. The low rate was set to 60 and for the most part at rest that's what my Apple Watch and o2ring says. The pm and leads were working on 1/3. I was in the office on 1/14 for a wound check.  They checked the pm and said it was working fine. As an aside after three weeks I can sleep on my side.
 

 At night and while sitting occasionally the rate will drop to the low 50s. The number of occurrence initially was 10 to 12 nightly last 8 to 120 seconds in duration.  Over the past 5 or 6 days the number of occurrences has decreased a bit.

When I asked the nurse she dismissed it as a "recording device" issue.   At the time I didn't have the data to back up my concerns. I went home and spent an hour analyzing the data.  Once I felt the recordings were valid I pushed the issue with the cardiologist.  They wanted a reading.  Sent the reading and now I need to go in on Thursday for some fine tuning.  They're going to turn on auto check. I've been all over the Medtronic manual site and searched the internet without having any success.  That term might be the nurses interpretation of what the option does.  I imagine it probably triggers more diagnostic data when an event occurs. 

I think the rate dropping is fine, I feel fine and I'm thinking it's the hysteresis tunable.  I do find  the long durations perplexing.

So I guess the question is has anyone experienced this hr drop below the low value set by the cardiologist for long durations?

Anyone have any experience with this auto check feature?

Thanks


10 Comments

Rate drop

by AgentX86 - 2022-01-26 01:36:37

Watches aren't really very good at measuring heart rate.  They're useless if there is any arrhythmia going on.  PVCs are quite common after PM implant. The watch won't see them and if you're counting by palpating your wrist, you may not feel them either, though you may feel the arrhythmia.

There is a lot of information on PVCs in previous posts but essentially they're an early heartbeat (PVC = Premature Ventricular Contraction).  The real one is there too but you (nor your PM) will see it.  After the PVC the ventricles  don't have a chance to fill completely causing what may feel like a skipped beat.  It's not but it may be very weak.  Weak enough not to be felt in the wrist or counted by your watch.  If you feel for your pulse in your carotid or femoral artery, you'll get an accurate count.

It's rare that these PVCs would be dangerous.  Everyone has them but after a PM implant the heart is a little pissed off and it takes it a while to get used to being paced. 

Your PM doesn't record them because they aren't important and it has better things to record. PMs can be set to record strings of them but to show how unimportant they are, mine (a Medtronic also) can't even be set to record less than five in a row. It nail it down, I had to catch it in the act and send a remote transmission so they could look at the PMs EKG.

Your PM is not pacing you below its minimum setting.  Thats not how they work.

Watch and O2ring utility

by fxdci200522 - 2022-01-26 20:17:50

From past experience while in afib watches wouldn't work well while in afib and trying to get a pulse.

Currently no arithmias are occurring.  After a cardioversion in august and an ablation in September and a pm 3 weeks ago I watched the ekg monitor for about 90:minutes while I was waiting to be sent home.  No pvcs noted on the device at all.  My issue was low rate while at rest which the pm has corrected.  While in bradycardia The Apple Watch would detect and log a low rate alert after 10 minutes below the low threshold.  The o2ring would immediately alert for 10 minutes when the low threshold was breached.

I have a sense that your point about the heart being pissed about being paced is very much correct.  The first 7 to 10 days I had a lot of event < 60 at night for varying durations. Over the past 6/7 days the number of occurrences and durations are shorter.  So perhaps it's tolerating it better.

Rate dropping

by AgentX86 - 2022-01-26 21:46:28

When you were watching the EKG was your heart rate below your PM setting?

My point is that your PM won't lie but anything measuring your heartbeat on your wrist can easily lie because not every heartbeat will make it to the wrist.  It's there but it can't be detected in the smaller arteries going to the hand.  The heartbeat will be detectabe in large arteries like the carotid and femoral.

It would be exceptional if your PM really were going below it's minimum. i suggest that you do a remote transmission when you see this low rate. That'll put a nail in it.

Discrepancy

by Gotrhythm - 2022-01-27 12:51:53

Obviously nobody here can diagnose you with PVCs. However they are common. Many of us have them and have observed the apparent dip in pulse rate as measured by our at home devices that sometimes happens concurrently with PVCs we feel.

Could you be having PVCs even though you observed the EKG for 90 minutes and didn't see one? Sure. To me, PVCs are like the weather. Sometimes the sun shines all day. Sometimes it rains. Seeing an hour and a half of sun doesn't mean it won't rain tonight.

The nurse who dismissed your concerns as a "recording device issue," unhelpful as that seems, was essentially right. Your pacemaker is directly sensing electrical activity at the heart. The wires are actually touching the heart. PVCs and PACs (premature atrial contractions) though inefficient, are "real" heartbeats and the pacemaker will count them as such.

All our other devices are sensing at some distance from the heart. We use them to infer things about the heart, but it's important to remember that they are actually measuring is what's happening at a wrist or fingertip. Does the signal travel that far? Hopefully yes, but sometimes not. Sometimes there will be a discrepancy between what the pacemaker records and what other devices report.

When there is a discrepancy it only makes sense to trust the pacemaker since it is closest to the heart.

For more information on PVCs and why different devices will report differently, see the Youtube video PVCs:Symptoms and Treatment--In Plain English! by Dr. Joshua Cooper. Sorry I don't have the URL.

Hope this helps.

Low Rate

by Flo - 2022-01-27 15:51:01

I was upset a few months ago when I felt my heart beating irregularly (PVCs) and checked my oximeter to find the pulse rate was dropping below my low set rate of 60.  I read an older posting concerning same on this forum saying oximeters, etc do not always detect the weak premature beat and show a low HR.  It made sense and was good to know.

Thanks for all the replies

by fxdci200522 - 2022-01-27 16:41:34

If the drops below were of  short duration I could agree, but most that have been caught are 12 to 20 seconds in duration.  The longest one caught was 126 seconds.  As a look at the loggings the thing that strikes me odd is why did it drop to only 52 and stay there for 100 seconds.  My low rate pre-PM was typically 42/44.  So I think that there may be some value in suggesting something is going on with the O2RING. 

Today the cardiologist enabled bipolar pacing and hopefully as someone has mentioned the heart is somewhat objecting to being paced and will adjust asI feel crappy.

Low rate

by AgentX86 - 2022-01-28 12:18:53

100 seconds is a very short time.  When it  happened to me, it was an hour or more. I had the problem until they raised my minimum rate to 80bpm and it's been there since I got the pacemaker four years ago.

Sorry you're not feeling good

by Gotrhythm - 2022-01-28 13:52:47

You seem to be under the impression that PVCs (if they occur at all) only happen once or twice. Not true.

You can have just one PVC and then no more, or PVCS randomly spaced over several minutes, or the PVCs can even become "regular."  When I was having bigeminy--one PVC every other beat--my pulse measured by my pulse/oxymeter was 35, exactly one-half my pacemaker setting of a minimum of 70 bpm. It could go on for anywhere from a couple of minutes to several hours.

A person can also have one PVC out of every three beats (trigeminy) one in four (quatrageminy.) The list goes on.

One or two PVCs randomly spaced over several minutes probably won't make a noticeable difference in how you feel. A lot of them, occuring frequently will make you feel terrible or "crappy" to use your word.

Again, I can't tell whether you are having PVCS or some other arrythmia that has some of the same effects. Let our doctor how you feel. Although the vaious arrythmias  aren't caused by the pacemaker sometimes a pacemaker adjustment can make them less bothersome.

Or it might be time for a Holter monitor to get a clearer picture of what's going on.

ditch the watch

by dwelch - 2022-02-01 16:21:42

I would ignore anything a fitness tracker or watch says.  Would certainly not bother the doc about it.   FULL MINUTE against a stop watch or clock taking your own pulse, no 10 or 15 second shortcut.  The EKG if you end up at the doctors office is what matters.  If you can turn off heart stuff on your watch, do that.

Hysteresis is likely your answer

by bposter - 2022-02-07 17:41:24

I had them disable hysteresis altogether and it made things much more straight forward. That's my suggestion, but my main rate is set at 50 so dipping below that is fairly noticible. It happens primarily while I'm asleep. All that said, lately my watch has started to tell me that I'm droppping below 50 for a few minutes at a time while I sleep. I'll be trying to figure that one out, the idea that my pacemaker isnt capturing properly makes me uncomfortable.

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