A Pulse Oxymeter CAN log your pulse and you can view your night' sleeping pulse to determine if your heartbeat is irregular. If you do see irregular, a cardiologist can measure using an EKG but will generally want to do this as a stress test. You can get a Pulse Oxymeter on amazon and get one that looks like a wrist watch and the probe is in the form of a little doo-hickey you stick on your finger. Mine can record all night and store quite a few night's results. I bought mine to measure blood oxygen as I was scary-low prior to therapy.
Thanks Wired George and this is of course correct. However, if anyone suspects a fib you should seriously visit a cardiologist. This is not a condition you want to diagnose on your own. The EKG is the first diagnostic tool and obviously the cardiologist will determine the course of remaining testing based on the individual patient's symptoms. Medical conditions like this are not a one-size-fits all.
I found my heartbeat a bit irregular based on the findings from the Pulse Oxymeter data. Went to my PCP and she told me I would probably drop over dead on the spot and rushed me to a cardiologist. He gave me a stress test and irregular hearbeats became very regular so he said I shouldn't worry and the PCP should be a bit more careful rather than frighten an old buy like me. Point is, the EKG would be great and the first tool of diagnosis if everyone got one in conjunction with a yearly physical but the tool I used was helpful in getting me pointed in the right direction as well as monitoring blood-oxygen saturation which had dropped down to about 70 for sustained periods prior to therapy. The Pulse Oxymeter was very valuable to me to give me confidence that PAP therapy was working for me as it should.
Everyone's mileage with a physician will vary and a patient must always manage this.
There are two important points here: 1) a fib and oxygen saturation with sleep apnea are two distinct issues 2) if you suspect you have a fib, don't wait for a physical, get in to see a physician right away. I'm not questioning the value you point out about a pulse oximeter; I have one also and you are correct that it can be helpful in monitoring oxygen saturation. It is not, however, a replacement for seeing a physician about concerns for afib. See more here: http://www.heart.org/HEARTORG/Conditions/Arrhythmia/AboutArrhythmia/Why-Atrial-Fibrillation-AF-or-AFib-Matters_UCM_423776_Article.jsp