Pulse Oximeter

Subject: Pulse Oximeter:

Last August the ER doctor found my pulse to be 30 bpm. Until this point, I had no interest in what the pulse does, I knew I had one and that was good enough for me. My painful sciatica was completely ignored, as I was hospitalized for Bradycardia and overnight observation.

My sciatica was the result of sitting around for seven weeks with an arm sling while recovering from Popeye bicep surgery. I did not know it at the time, but I was in for 6 months of PT to rehabilitate three torn roto cuffs and the gentle bicep exercises. I became very interested in cardio and pulse oximeters when my physical therapist used one on me. I went home and ordered one from Amazon.

This is when I became obsessed OCD style with my pulse. I would walk around with it on my finger. To me there seemed no logic to the readings, and as an engineer I needed statistical facts. I would test my resting rate and be able to relax and bring it down to 30, 31 and 29 on occasions. At this time, I purchased and returned two smart watches, the pulse app did not work!

I then touched base with my wife’s cardiologist  and discussed the low readings with him. After several visits he did a 30-day study with an adhesive Zio link, and further to this a Biotroniks Linq, he told me not to worry he had a stethoscope on me 24/7. I put away the Pulse Oximeter and trusted this arrangement.

Five weeks ago, I eventually had a pacemaker fitted. After a few days I needed to see it was working properly, the pulse had been set to 60 bpm. I was panicked to see the low readings once again. I tested the Oximeter on my wife, it read OK with her. We did the same with a Blood Pressure monitor, the same thing. Had the leads come out, or was the pacemaker set correctly?  

Our Cardiologist seeing my concern gave me an appointment the very next day, he thankfully fitted me in.

Everything was fine! The technician explained the PVC’s that I had were giving false readings for my pulse. He kindly demonstrated this: He put the Oximeter on my finger, and with his computer tuned out the PVC’s. I was amazed and relieved to see my pulse jump from 40 to the correct 80.

In conclusion: I learnt if you have Bradycardia-low pulse mixed in with PVCs most commercial devices will not read correctly, Including the two smart watches I had returned!!.  


6 Comments

PVCs

by Penguin - 2023-11-08 19:44:13

Hi, 

What an interesting story. 

Tell me, did the ER doctor who kept you in hospital overnight for observation, find the PVCs too?

Since receiving the pacemaker are you symptom free from the PVCs or do you now have symptoms. It doesn't sound as if you were symptomatic before the PM?

Obsessing over your pulse is a habit to get away from once the initial impact of your diagnosis dies down. It can be difficult not to obsess initially though. We've all been there! 

 

My PVC's

by ANDREW75 - 2023-11-08 21:19:24

Hi Penguin,

I needed to check and reviewed my overnight stay report, yes, they did find PVC’s and mentioned them as:” Frequent PVC’s”. This was the first time they were mentioned.

Both links picked up my PVC’s, but I had no knowledge or pain from them, so I was very lucky in this regard.

With the Pacemaker I still have them last time mentioned around 9,215 per day. So, they seem to be frequent but not apparent to me. I don’t know what this means, but my Cardio guy said he may have me on prescription if they don’t go away with exercise soon. He prescribed Cocoa nut water for the electrolytes, and my wife and I nick name this as “Electronic Juice” since we both take it!

As an engineer I am looking for exact correlation between activities and PVC’s, good luck to me!!!  

9,215 PVCs per day

by Penguin - 2023-11-09 04:52:34

That sounds like rather a lot of PVCs p/day to me! 

I'll wait to see what others say on the subject as PVCs are not something I feel able to discuss knowledgeably.

In the meantime this article re: PVCs and exercise may be of interest.  https://www.healthline.com/health/fitness/is-it-safe-to-exercise-with-pvcs

 

PVCs

by piglet22 - 2023-11-09 06:58:55

Hello

Welcome to the club and relating your experiences.

I can throw some light on some of this as I have had Complete Heart Block (CHB) for over 18-years, pacemakers fitted and now suffering the additional effects of PVCs (diagnosed as VEs or Ventricular Ectopy or Ectopics)

Firstly, I use an oximeter on a daily basis and deliberately bought the same model as the GP used (ChoiceMed).

VEs can be electrically sensed, but can be weak enough not to register as a palpable pulse, say the radial pulse at the wrist.

To quote my pacing consultant, VEs are rubbish.

An oximeter is useful but is not the best way to measure a pulse that contains strong "normal" pulses and weak VEs. The oxygen level is less likely to affected.

Your reported PVC burden of over 9000 a day is significantly high. I get 2400 a day and that is enough to cause me physical symptoms like blackouts and falls. These figures are averages so you might get none in one hour and a lot in another.

When I get the first signs of ectopics kicking in, usually after relaxing after exercise or waking up in the middle of the night, I always go for the radial pulse, then the oximeter and the most reliable, a decent blood pressure monitor with arrhythmia sensing (Omron MIT-10 for example).

It's taken a while for me (scientist/technologist/part time engineer) to get my head around how VEs interact with the pacemaker and ultimately physical symptoms.

Initially, I was reporting pulse rates in the low 30 to 40 BPM even with the base IPG (Implanted Pulse Generator) rate set to 60 then 70-BPM. This is the minimum rate that the PM should maintain.

Time and time again, the technicians would say "pacemaker is working fine". Clearly their definition of fine and my definition were different.

I could be sitting down, get up and within a couple of steps, be grabbing something to stay upright. It didn't always work.

Slowly, through some knowledge of programming and coding devices similar to those in PMs, it became clear, later confirmed by the consultant, that what was happening was the VEs were being sensed by the PM, then included in the PM pacing timing.

The PM timing reacts to "normal" pulses or PQRST signals and if it deciphers a VE as "normal", it doesn't bother to sequence a pulse as it would do if the minimum rate fell below the IPG rate. 

In effect, the VEs introduce a pause into the pulse train.

When the technicians interrogate the PM, they may well see a normal rhythm on the ECG and report normal operation.

Deeper down in the interrogation, the PM might be recording the ectopics, but this could  be ignored if you aren't experiencing symptoms.

You may have heard of watchdogs in computing, where a gap in in a train of pulses is used as an alarm if one goes missing. In a roundabout way, the VEs are telling the watchdog that all is well when it isn't.

I'm surprised that the PM manufacturers haven't got a routine available to filter out VEs, but I 've been told they haven't, or the problem would have been fixed.

At the moment, the only solution other than a surgical one, ablation, is to increase my dose of beta blockers to the maximum dose (10-mg daily Bisoprolol fumarate) to smother the VEs.

I'm in the middle of a run of tests including echocardiogram and likely Holter monitor.

I used to exercise regularly, biking, throughout the 18-years of trouble-free PM support and kept detailed records of BP and BPM. Not once did the PM go below the IPG rate. I decided biking was getting too dangerous and I was picking up injuries. In the road pecking order, cyclists are seen as a nuisance. I now walk.

It’s a different story now and I’m assuming it’s a progression of the original condition.

Good luck

Oximeter - Penguin and Piglet22

by ANDREW75 - 2023-11-09 18:11:53

Hi Penguin,

Thank you for the exercise-PVC link. I have read it and saved it for future reading.

I’m wondering if my high level of PVC’s will go away with exercise or not. They may be totally unrelated, so it’s a wait and see situation. The article was informative, and the concern is that exercise in some cases induces PVC’s. I also note the different choices of exercise. Since I have been given permission, I have gradually been increasing my cardio. It’s kind of frightening to be honest.

I would like to monitor PVC’s at least when exercising. I have yet to find a device for home use, so will rely on the Pacemaker readings. My new plan is to record my gym time and dates and overlay this at my 3-month checkups to see if they are worse or improved, or even unrelated. My wife and I are on a joint three-month checkup, we call it a “double date”. We know the Doctor and Technician very well, and they are very obliging, and we have a family-friends atmosphere. 

 

Hi Piglet22,

My recent report since the Pacemaker was installed for 13-day period shows my PVC’s expressed as 28%. I do not know what this means and also get the impression they are mild in depth perhaps.

I certainly do not get any sensation like you with yours. I am hoping my PVCs are “Rubbish” as you mentioned. I personally have no idea as to the spread, when or how deep my PVCs are. I was very skeptical when my Oximeter show low pulse readings 30 even with a new Pacemaker. I felt relieved when the Technician tuned out the PVCs to show me my pulse was above the 60 bpm setting around 80 bpm, this was with a Biotronik PM. I was having them there and then in the office. Maybe in future they will be able to tune them out at the PM.

I have had no blackouts, falls and am increasing my exercise not decreasing like you. It must be frustrating for you with an enquiring mind not to get answers, after 18 years of good performance from your PM.

I have read your bio; I am also from the UK residing in the states Ca since 1977. I am 75 and hoping my PM will get my Mojo back and I can go windsurfing again.  

Thank you for posting. I value your insight. I am brand new to this area but take note for my future of your experiences.

Good luck with your current tests.

Good to Hear about the Monitoring

by Penguin - 2023-11-10 15:54:17

Thanks for the feedback. I'm pleased that you found the article useful. 

From what you say your EP and techs are keeping an eye on you and they will know you and your history best.  

Please keep us informed.  

Best Wishes

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