Finger Oxymeter can lie about your heartbeats

When I was in Ambulatory Care they did the stats and put the finger oxymeter on and scribbled it all down and went away. Sister pops back and asks if I have AF still? I said yes? Okay no problem I need to do a physical check of your pulse then for the full minute. It seems that when in AF it will calculate the heart rate based on the faster heart beats. This will also do it on the single ones the doctors and bought from Amazon etc. do.

So I could show 159 on the oxymeter but on the AF real time check I could be 130. The one I have does show each beat so I can usually see it going into free jazz mode. But I have seen the difference my self on my own so another fact I can add to my list of useless facts.

Be Well

5 Replies

  • Hi as you probably know this also affects bp readings on automatic machines for much the same reason - it normally monitors them high or erratically just like fast AF pulses ! As my BP is normally completely different every time it is taken when in AF , the nursing staff write down nicest one! x

  • I like your nurses.

  • I thought it had been mentioned here so many times that these machines often fail to give proper readings. The only record should be from manual pulse checks or ECG. BP machines. pulse meter etc. seldom have the capacity to acurately read a pulse when in AF.. A good reminder though Offcut.


  • Thanks. I must of missed the posts before?

  • I did a lot of searching before I bought a cuff monitor last November and I only found one suitable for AF and it is an automatic one. It is the only one recommended by NICE and it is actually the one listed on the AFA website. It is the Microlife WatchBP Home A (note the A on the end which is the version suitable for AFib. I bought one off Amazon and was able to buy it excluding VAT. I have cross checked a few times this against the AliveCor HB results and the correlation is very good usually only 2 to 5 bpm different which in any event is good because your pulse can vary that much.

    As well as the finger pulse monitors being inaccurate so are wrist monitors. When I purchase my WatchBP monitor I cross checked it against a well known brand of wrist monitor and the wrist monitor was typically 30% to 90% high (ie almost double at the top end). As in persistent AF which was reasonably stable it was easy to truly compare.

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