Pulse below pacer low limit

Hi---new member here.
Just had a pacer put in this week with a low limit of 60. Things were going fine until yesterday, when I checked the pulse ox my pulse bounced around 40s and 50s even going to 30s once. I do have AFib and when pulse ox was registered 60 the first days was likely out of it. I believe I'm probably in it now. Even so, the low numbers scare me (I dont mind when it goes 70s 80s).


Get that checked

by BradyJohn - 2023-09-04 02:03:21

Hi there and welcome to the club that (as others have said here too) no one wants to join.  I have had a pacemaker for about three and a half years now, with no regrets.  One comment, sometimes certain devices may have difficulty accurately reading a paced pulse.  I eventually tossed my older version Garmin watch in the drawer just for peace of mind.  Also, it seems to be fairly common to have some issues early after implant.  That being said, if you're in afib or think you are for an extended period, I would be seeking medical advice.

All the best, I hope your team gets you sorted soon,


Ectopic beats / Missed beats

by Penguin - 2023-09-04 04:18:55


There are members on here reporting the same low pulse readings - with symptoms.  Have you been symptomatic? If so you need to contact your clinic. 

If not and you are taking these readings from a watch (as described above) they may be misleading.

As you know A.Fib is a fast, erratic heart rhythm. Pacemakers are often set up to mode switch to a pacing mode called 'DDI' when this happens, so that the fast, erratic beats are not tracked down to the ventricles. This is to avoid distressing symptoms.  

Gemita, the moderator here, posts widely on the subject of A.Fib. and other atrial arrhythmia. I'd suggest that you wait for a response from her as she knows a great deal about this subject. 

I will say though that the pacemaker operation / implant often triggers arrhythmia and they can take a while to settle.  You should be due a review in clinic and the interrogation 'should' show any episodes of A.Fib. They are often described as Atrial High Rate Episodes - (AHRE). 

Best Wishes


by new to pace.... - 2023-09-04 07:30:58

It would help in answering your questions if we know the make, type, model of your device and your  location. As the answers sometimes depend on that information.

new to pace 


by Newpace - 2023-09-04 10:24:00

Thanks for all the comments. What a great forum.

--I have no symptoms

--Now I appear to be more in in rythm - but the finger pulseox still reads 55 ish. It's bouncing around in the mid - upper 50s.

It is just a CVS model:


Is there a difference between pulse and HR? I seem to remember in the hospital there were two readings? Is the Pacer set to one? Are both in synch when I'm out of Afib? Which - if one or other are different - is limited by the Pacer?

So many questions .....

Pulse/heart rate and the use of oximeters

by Selwyn - 2023-09-04 13:02:15

The pulse should correspond to the heart rate, unfortunately this may not be the case.

Arterial pulses may be absent or not felt depending on the state of the arterial wall. It is even possible to have no pulses in a limb due to  a blocked artery and alternative circulation opening up.  You have easily felt arterial pulses in the neck, upper limbs, and groins. It is unlikely all your arteries are bliocked!

All electronic devices can be inaccurate. More so when using fingers ( for instance some people have spasm in their finger arteries in cold weather) and ill fitting oximeters. It is best not to rely on such devices for pulse rate. Atrial fibrillation will not be picked up by such devices. The pulse rate is therefore inaccurate. It ican be  quite hard to feel a completely  irregular and fast pulse such as atrial fibrillation. 

You can usually feel your heart beat ( typically for a normal size heart it is in the left 5th rib space in a line with the middle of the left collar bone), should you not have any problems such as excess fat, or effusions, emphysema.  Those of us with hypertrophic cardiomyopathy have a pronouced, apex beat. The apex beat is best felt lying on your left side.

I find my KARDIA ECG gaget an accurate device which is very good for detecting atrial arrhythmias.  If you really want to know whether you are in AF I suggest a purchase.

Erratic pulse ox numbers

by Gotrhythm - 2023-09-04 15:04:08

Welcome to the wonderful world of electronic devices. As you are already discovering, coming to terms with the pacemaker is just the beginning. 

But let's start with the pacemaker. Those funny pulse ox numbers you are seeing do not mean the pacemaker is falling down on the job. Pacemakers are incredibly reliable. If we could see a readout of what is happening at the level of your pacemaker, we would see it timing every heartbeat to the hundredth of a second. It knows exactly when the next heartbeat should occur, and it will supply a beat before you could possibly be aware there is a lag.

So what do the pulse ox numbers mean? My first guess is that you are having PVCs--not uncommon immediately after getting a pacemaker. A PVC is a heartbeat, so the pacemaker counts it, but it is an inefficient beat, and it might not be strong enough for your pulse ox to measure it in your finger. A finger a long way from your heart.

(Just do you know: somebody else mentioned ectopics. A PVC is a kind of ectopic beat)

I know it seems strange, but a pacemaker can't do anything to keep your heart from doing PVCs. Fortunately, PVCs aren't dangerous, and despite them, the pacemaker knows how to keep your heartrate steady.

About mode switching, I am clueless, but it might be something you need to learn about if you have a-fib. I don't know what effect that could have on pulse ox readings. 

But now is the time to learn the most important self-test you can run. How do you feel? Really it's the only reading/test that matters. Our weewonky, unruly hearts can run rhythms that no device yet made can unfailingly report and interpret. But we do have a pacemaker, and it will make sure we have heartbeat that's regular enough to keep us alive and with any luck, feeling good.

So here is the takeaway. If you are feeling okay, don't worry about the pulse ox numbers. But if you're not feeling good, and the pulse ox numbers don't look right, it might be a clue that the not feeling good has something to do with your heart rhythms.



You know you're wired when...

You have a $50,000 chest.

Member Quotes

I am very lucky to have my device.