I assume the heartrate calculation in the app uses an interval to create an average, then publishes the average as the current heartrate, redoing the calc every X seconds against a slightly shifted dataset. Generally this interval can be quite small due to normal heart beats being consistent and regular. An example of this we have all done is when we count the # of beats in 15 seconds and then multiply by 4 to get a heartrate expressed as beats/min.
For users with Afib, where the timing between beats varies significantly and irregularly, the interval chosen is critical to a useful reporting of 'heartrate'. If the interval is too small, then the heartrate could be 'un-usefully' variable.
It would be good if the app allowed for the user to set the interval, this would then make the heartrate reported to be useful.
