According to the cardiologist I may or may not have occasional atrial fibrillation. He said it would be useful to have access to a portable EKG in case I felt some symptoms so I could get a reading at the time. One option is a $200 kardiamobile device and another is a smartwatch that has an EKG app such as an Apple watch.

I don't normally wear a watch other than a golf gps watch when golfing so the extra spend over the kardiamobile isn't great value, but on the other hand, if I'm out somewhere and I feel symptoms, the kardiamobile is no use sitting at home and I could live with leaving a watch on for a month or two.

Anyone have any experience of these? My cardiologist says both devices are reasonably accurate and medically worthwhile.

The other question is: are Apple watches a risky 2nd hand purchase? In terms of battery health, IMEI lockout etc? Any models to avoid? 

TIA

JohnO